,,ketchup ------- ,,methods ,,of ,,manufacture ,a4 ,w4 ,,bitting ,,microscopic ,,examination ,k4 ,g4 ,,bitting ,,lafayette1 ,,ind4 ,,murphey-,,bivins ,,co4 ,,press #aiae ---------------------------------------- -------------------------------- ,this brief presentation of some facts concerning the manufacture of ketchup and discussion of the methods for its examination is offered in appreciation for the many favors shown to us by manufacturers4 ,the text has been kept as free from technical terms as the subject would permit1 and the results of observations and experiments covered by direct statements instead of giving details and tables4 ,nothing new is offered in the method of manufacture1 but the doctrine of the use of sound fruit1 sanitary methods1 and sterilization is reiterated4 ,the position taken upon the method of examination is not new but it is thought proper to present something concerning this phase of the work to the manufacturer4 ---------------------------------------- -------------------------------- ,,ketchup ,ketchup is a spiced sauce used for its condimental effect in imparting flavor1 or to give relish to other foods4 ,it receives its distinctive name from the base used1 as1 tomato1 grape1 currant1 mushroom1 walnut1 etc4 ,the terms ketchup1 catchup1 and catsup are used to designate any spiced sauce and seemingly without any reason for the one used other than personal preference4 ,though the derivation of the term has been attributed to different sources by the dictionaries1 there seems to be more reason for the use of the term ketchup than for the others1 both upon the ground of its prior and more general use1 and from the history of its derivation4 ,murray#a gives the derivation of ketchup from the ,amoy dialect of the ,chinese1 the term being koechiap or ke-tsiap1 meaning a brine of pickled fish or shell fish2 and he states that the ,malayan kechap1 which has been claimed as the original source1 may be from the ,chinese1 but that the word kitjap1 as given by some dictionaries from the ,japanese1 is an impossible word for that language1 and is possibly an error for ,javanese4 ,the term catchup given by some dictionaries appears to be based on the assumption that the first syllable ketch is a colloquial form of catch4 ,many manufacturers use the word catsup1 a spelling for which there seems to be no etymological warrant4 ,the earliest use of the term catsup1 found by the writer1 with any particular significance attached to it as distinct from the other two terms1 is by ,kitchiner1 an ,english physician1 in the ,cook's ,oracle1 in which directions are given for reducing 8catchup0 to half the quantity1 the statement being that 8it may then be called double cat-sup or dog-sup40 ,the first edition of the book appeared in #ahag in ,england4 ----- ,footnote #a3 ,murray1 ,j4 ,a4 ,h4 ,new ,english ,dictionary4 ,,the ,,manufacture ,,of ,,tomato ,,ketchup ,it is but natural that a product of this kind should vary greatly in flavor due to the selection and quantity of spices1 salt1 sugar1 and vinegar used1 and in consistency due to the degree of concentration and fineness with which the base has been comminuted4 ,most of the recipes for home-made ketchup call for rather liberal spicing and long cooking so that they have a fairly heavy body4 ,these insure good keeping quality1 but impart a dark color to the product4 ,the manufacture of ketchup upon a large commercial scale is of rather recent development and is confined almost wholly to the use of tomatoes as a base4 ,there was little ketchup of the kind best known at present made prior to #ahij1 as most ketchup was made by what was known as the natural fermentation method1 that is1 allowing the tomato pulp to ferment spontaneously and using the solid portion for stock4 ,this method was continued1 though on a decreasing scale1 until #aijh1 at which time it was practically prohibited4 ,beginning about #ahij1 ketchup was made from fresh pulp and barrel stock without fermentation1 the fermentation being prevented by the use of a preservative4 ,the method is still in use4 ,the first extensive manufacture of non-preservative ketchup began about #aijh1 though a few firms had been making it prior to that time1 the pioneer probably being ,e4 ,c4 ,hazard1 of ,shrewsbury1 ,new ,jersey4 ,from the amount of space given to the subject of ketchup in the canning and food journals1 one might conclude that it is a difficult product to make1 or that it is one of very great importance4 ,it is in reality very easy to produce1 but has assumed a prominence among food subjects which it does not deserve1 due to the fact that some manufacturers have not yet learned the necessity for using care1 or persist in using material of questionable quality4 ,ketchup is made in the home with very simple apparatus2 a colander or sieve for breaking and straining the pulp1 and a copper1 porcelain1 or earthen kettle for cooking1 being all that is necessary4 ,the cooking of the tomatoes with the spices1 sugar1 vinegar1 etc41 is generally done slowly1 until a heavy body is obtained1 which results in a dark color1 but insures sterility of the product when it goes into the container1 and also contributes to keeping quality after it is opened4 ,in the factory many refinements are necessary to make a commercial article which will attract the eye as well as satisfy the sense of taste4 ,the usual dark colored1 rough1 home-made article will not command a sale over a grocer's counter alongside of that made in a modern commercial kitchen4 ,here1 sorting tables1 washing machine1 scalder1 cyclone for pulping1 steam-jacketed kettle1 tanks with coils1 or vacuum pan for cooking1 finishing machine1 bottle washing1 and filling machine1 are all necessary4 ,the pipes carrying the pulp from one machine or vat to another must be enameled1 bronze1 tin-lined1 or silver-plated to prevent the fruit juice from coming in contact with iron or anything which will cause discoloration4 ,the work is done speedily1 and the cooking done in the shortest possible time in order to secure the brightest color and smoothest consistency4 ,the stock should be whole1 sound1 ripe tomatoes1 preferably grown near the factory so that they may be delivered promptly after picking and with the minimum injury4 ,they should be picked when in prime vine-ripened condition4 ,fruit picked when just turning and allowed to stand one or two days to color will not have the same rich flavor as when vine-ripened1 but will stand rougher handling4 ,green fruit gives a weak color1 and over-ripe fruit is prone to become injured and spoil in handling4 ,the tomato should be through the process of manufacture within twenty-four hours from the time that it is taken from the vine4 ,repeated experiments have shown that rapid handling of fruits and vegetables gives the best results for canning1 and the tomato is no exception to the rule when used for ketchup4 ,the variety of tomato used is of importance4 ,the tomato will vary in solids from less than #e4e per cent to nearly #h4ge per cent2 in soluble solids from less than #c4e to nearly #f4e per cent2 in sugar from about #b4be per cent to #d4be per cent2 and in acidity from 4#c per cent to 4#f per cent4 ,the colors will vary from an almost creamy white to a very deep red with variations in yellow and purple4 ,the only way to get uniformity in a product is to select one good variety and discard others4 ,the preference is for a clear red smooth tomato of medium size1 firm1 and of fair acidity4 ,while color may be only 8skin deep0 as far as being red1 yellow1 or purple is concerned1 experience has shown that a clear red variety gives a better and more lasting color than yellow or purple4 ,a medium sized smooth tomato is preferred because of less adherence of dirt1 fewer cracks1 and generally more even ripening to the stem4 ,a fairly acid tomato imparts more flavor and needs less vinegar in the finished product4 ,the fleshy portion of the tomato gives the body1 but the pulp about the seeds furnishes the characteristic flavor4 ,the collecting of tomatoes in the field should be done at short intervals so that the fruit may be taken when in prime condition4 ,where picking is done at too wide intervals1 there is a tendency to take fruit that is only colored and not really ripe1 and for some to be left and become over-ripe4 ,in both cases the manufacturer is the one to suffer1 by increasing the expense of sorting1 holding the green if he is to make a high grade product1 and by waste from cracking and mashing of the over-ripe4 ,the stems should be left in the field1 as they increase the weight and may injure the product to a certain extent4 ,the handling should be in shallow crates4 ,these should have strong cleats across the ends so that one may be placed above the other without touching the fruit1 and if of considerable length1 should have a partition4 ,the cleats permit space for ventilation in case they must be stacked for a few hours or more4 ,the depth should be such as not to permit more than three or four layers of fruit4 ,the deep box and the conical basket are not well suited as carriers and should not be used unless delivery can be made by wagon direct from the field and within a few hours after gathering4 ,it is the rule to see cars and barges loaded with baskets arrive at the factory with more or less of the fruit in bad condition4 ,when one basket is set on the edges of two or three others in stacking1 there is always cutting of a few of the top fruit1 the movement in riding causes others to gradually settle and pack into the cone shape of the bottom1 so that if they be held for a day or more1 there will be loss of juice1 consequent growth of mold1 and contamination of the sound fruit from the infected4 ,the actual loss from this form of handling has not been determined1 but is undoubtedly much larger than is generally supposed4 ,it is the belief of the writer that the loss is not far from #aj per cent4 ,it is certainly much greater than the difference in the cost of freight and handling of the box over the basket4 ,all baskets and boxes become more or less infected with mold during the season and this spreads to the fruit1 the contamination increasing the longer the fruit is held1 the tighter it becomes wedged together1 or the greater the cracking4 ,the shallow crate affords the better protection4 ,when tomatoes arrive at the factory1 they should be purchased by weight for sound fruit4 ,buying by the box or basket is antiquated and not satisfactory to either buyer or seller4 ,under the recent ,federal net weight law1 purchase by basket or crate must show on each container the exact weight or measure if there be interstate shipment1 and the same is true for some of the states4 ,it should not be necessary to give more than a general inspection at the factory4 ,a contract for ripe fruit at ten dollars per ton1 which1 when delivered1 requires sorting1 and the holding of unripe and the discarding of defective fruit1 is equivalent to ten dollars1 plus all the additional cost in labor and the loss in making it fit for use4 ,if it be necessary to hold the tomatoes for some time at the factory before manufacture1 the crates should be stacked in tiers with a foot or more of space between each tier for the circulation of air4 ,stacking the tomatoes in solid blocks affords the ideal condition for the increase of molds4 ,there can be no doubt that large quantities of fruit have been lost each year from neglect of this simple precaution4 ,recently a method of holding in water has been originated by ,mr4 ,e4 ,w4 ,grosvenor1 at ,paoli1 ,indiana1 and consists in using large tanks capable of receiving #ejj or more bushels in which tomatoes are submerged in cold water as soon as received1 and then held until they can be used4 ,the device is based upon the theory that the tomato skin is practically impervious to water1 also that the molds require air for their development and by submergence in water their activity would be lessened4 ,these tanks are made with false bottoms to receive the sand and dirt1 are provided with jets to supply fresh water and to cause the tomatoes to automatically feed upon the conveyor4 ,the first impression is that the tomatoes are soaking in rather dirty water1 but tests show that they absorb very little1 if any1 water1 and examination at every stage shows them to be washed cleaner than by the usual method4 ,the work has not been carried far enough to be conclusive1 nor to indicate its limitations4 ,experiments made to duplicate the factory conditions1 comparing air and water storage for short periods1 were decidedly favorable to the latter4 ,much less change occurred in water storage for twenty-four to forty-eight hours than in the air1 and there was the further advantage that the tomatoes were washed freer from dirt1 sand1 and mold1 and that rot was cut out better under the water sprays4 ,some lots of tomatoes were held as long as eighty hours1 but this is not to be recommended4 ,when rotting does occur under water1 it is of a different character from that in the open and is far more offensive4 ,if tomatoes be accepted at the factory in a mixed condition1 that is1 greenish1 ripe1 and over-ripe1 they should be passed first over a sorting belt and preferably one which will turn all sides of the fruit to the inspectors4 ,the green fruit should be held out in separate crates to ripen1 and the unfit fruit be discarded4 ,if green fruit be not accepted1 the inspection can be done better after washing4 ,in any event the fruit must pass slowly on the table and in single layers4 ,no inspection can be made adequate if the tomatoes pile on the belt two or three layers deep1 or pass at such a rate that the eyes tire and all look alike4 ,this is a place where more belts moving slowly1 and fewer persons working on each belt1 will give the better results4 ,hand sorting is essential and far more important than in tomato canning4 ,in the latter the defective parts are cut away1 but no machine has yet been devised to make the separation complete in making pulp or ketchup4 ,one other point in inspection is the removal of the stems1 which should be the duty of the pickers1 but which is often neglected4 ,if the ketchup is to have the brightest1 cleanest color1 the removal of the stem is advantageous and1 furthermore1 if the tomatoes are raised on sandy ground1 there may be enough sand held around the stem to make appreciable grit4 ,some manufacturers leave the stem on to give flavor4 ,,washing4 ,the washing is the most important mechanical operation in making pulp or ketchup in order to get a clean product4 ,it is the weak spot in most factories1 but fortunately is the one that can be most easily changed4 ,the ideal washer is one that first receives the tomatoes in a tank1 holding them for a sufficient length of time to soak and to loosen the dirt1 and then submits all parts to a thorough spray under strong pressure4 ,most washers do not meet these requirements4 ,in many cases the tomatoes are either not dropped into water1 or go in and then out again so quickly that they are only made wet and bright1 but not clean1 then pass under a few cross-sprays1 each of which does not deliver a stream more than an inch or so in width1 the total spraying not being active over a space of more than six inches and only from above4 ,some machines do not actually spray the fruit more than one or two seconds4 ,in some cases1 it is not so much the fault of the machine as that of the owner in over-speeding and over-loading it4 ,most machines use a sufficient volume of water1 but not under sufficient pressure1 nor over a sufficient area4 ,one of the best washers in use is a slight modification of the cylindrical washer used for removing the lye and peel from peaches4 ,it consists of a cylinder about two feet in diameter and twelve feet long1 made of a specially corrugated iron4 ,the corrugations are sharper than the ordinary pressed metal used for building and siding1 and in addition they are perforated at frequent intervals4 ,this cylinder is mounted on a slight incline4 ,the tomatoes are fed in at one end and the revolving motion causes their discharge at the other4 ,the effect of the corrugation is to cause each tomato to turn over and over in its course and thus avoid all sliding4 ,a spray pipe passed through the entire length and1 when provided with the proper nozzle1 insures a thorough washing1 the tomatoes being under actual sprays from six to twenty times as long as in many machines that are now in use4 ,the water pressure should not be less than sixty pounds per square inch and is better above one hundred pounds if fine perforations or nozzles be used4 ,in nearly every case it is necessary to augment the natural pressure by an auxiliary pump4 ,the principle of the strong pressure is seen in using a hose without a nozzle to wash a floor and one with a nozzle and strong pressure4 ,in the former case it does not clean1 while with the latter it does and with less water4 ,the washer just described is too vigorous for tomatoes for canning1 as the treatment is too rough4 ,if the tomatoes are soft or badly cracked1 it causes considerable loss1 but not of material that should be used in ketchup4 ,the strong sprays will also cut off adherent mold and soft rot4 ,a thoroughly good washer will do about nine-tenths of the work for the inspectors4 ,during the past season some modifications have been made of this washer in the east4 ,the machine has been enlarged1 but better results would be obtained by using a greater number of small ones4 ,again1 some washing machines have been ineffective1 not on account of any defect1 but because of over-speeding4 ,the vigor with which the washing is done is always apparent in the finished product4 ,the poor washing usually given to tomatoes for canning1 accounts in a measure for the relatively large numbers of organisms found in ketchup made from trimmings4 ,,pulping4 ,after washing1 the tomatoes may be reduced to a pulp in one of three ways3 by running the raw tomatoes directly through a grinder and into the cyclone2 by passing the tomatoes through a scalder and into the cyclone2 and by turning the tomatoes into jacketed-kettles or tanks and cooking them until soft before running through the cyclone4 ,there is a difference in the product obtained by these methods4 ,the first one gives a somewhat larger yield1 as the hard parts are cut and torn so that more will be squeezed through the sieve4 ,the color is generally stronger and inclined to the purple side rather than the yellow4 ,the color1 however1 does not hold so well when exposed to light4 ,the pulp inclines to froth and there is a marked separation of red pigment on the top4 ,a raw pulp will begin to separate into a clear layer below and solids at the top in about fifteen to twenty minutes after standing in a tank4 ,this is due to the air incorporated in the solids and possibly to difference in specific gravity1 and not to fermentation1 as frequently alleged4 ,changes will take place more rapidly in such pulp than in that made from scalded fruit4 ,there is not a great deal of difference between the second and third methods1 the object in both cases being the same4 ,if a long scalder be used1 the skins will be loosened and the tissue softened so that it will be easily separated from the green parts1 hard cores1 or black rot4 ,there will be no acquisition of color from the stems to discolor the ketchup4 ,the loss is a little heavier in scalder heating than where the fruit is cooked in the tanks1 but there is the compensation that there is less carrying of hard or objectionable material4 ,a scalder to be effective should be much longer than that used in canning1 or a greater volume of steam should be used4 ,the tomatoes should be heated to about #ahj deg4 ,f4 ,there is little choice in the two methods1 but the preference is with the scalder1 both being preferred to the raw ground fruit4 ,a pulp made in this way separates slowly and there will be no material increase in organisms for a rather long time 7three or four hours74 ,there is less separation of pigment on cooking and there is a clean look to the tissue under the microscope4 ,in making pulp it is important that the paddles in the cyclone be held back from the screen and the juice driven through by centrifugal force rather than by hard grinding4 ,when kept well back1 the green butts1 cores1 and tissues which have been hardened by brown mold are carried over the end so that there will be fewer black specks in the finished pulp and it will have a better appearance under the microscope4 ,the pulp should be conveyed immediately from the cyclone to the cooking kettle1 and the next operation begun at once4 ,a storage tank is unnecessary when there is large cooking capacity1 and in most cases it is a source of trouble rather than a help4 ,a sample should be taken as soon as the batch is drawn1 and the specific gravity determined so that the proper quantity may be used to give a finished product of uniform consistency4 ,assuming that #ejj gallons of pulp will give a normal finished batch1 if the tomatoes are watery1 it may require #eej gallons or more to give the same result when concentrated4 ,this is easily calculated from the specific gravity so that reasonably uniform results may be obtained4 ,samples should also be tested for acidity once or twice each day so that the addition of vinegar can be governed accordingly4 ,the concentration of pulp will vary from #dj to #fj per cent depending upon its condition and the weight of body desired4 ,,cooking4 ,the cooking is done in copper-jacketed kettles1 in glass-lined metal1 or in wooden tanks1 the tanks being heated with coils4 ,the glass-lined tank has the advantage of very little metal coming in contact with the pulp and can be kept cleaner than wood4 ,a question has been raised regarding the suitability of copper for a cooking utensil1 though no positive objection has been made4 ,the vacuum pan is coming into use for concentrating pulp1 but has been little used in making the finished ketchup4 ,the jacketed-kettle is used by most manufacturers1 though the tank and coil is being adopted by those who wish to make large batches1 as it is the more economical4 ,agitators are no longer used1 as by proper handling of the steam and automatic traps1 little burning occurs on either kettles or coils4 ,the efficiency of the open tank or kettle is increased by providing a strong exhaust or suction for the air at the back and just above the top of the kettle4 ,a swiftly moving current of air across the top of the kettle will carry off the steam and shorten the time of heating from ten to twenty per cent4 ,a pulp may be reduced in a vacuum pan in about one-fourth the time necessary in the open kettle and with a marked conservation of color and flavor4 ,the vacuum pan may be used for quick reduction and the finish be made in open kettles in order to apply the heat long enough to spice and to sterilize4 ,there are possibilities along these lines which have not been developed4 ,the time of cooking a batch of ketchup will depend upon the equipment and the consistency of the finished product4 ,with a good kettle or coil and ample steam-supply a batch should be completed in from thirty-five to forty-five minutes4 ,this gives sufficient time to get the most desirable flavor from the spices and is not so long as to result in discoloration4 ,,seasoning4 ,the selection of the spices depends entirely upon the flavor desired4 ,cinnamon1 cassia1 cloves1 allspice1 mace1 pepper1 paprika1 cayenne pepper1 mustard1 ginger1 coriander1 bay leaves1 caraway and celery seed1 are all to be found in the various formulae4 ,some manufacturers spice lightly in order to retain the maximum of the base flavor1 while others go to the opposite extreme on the misguided assumption that they will act as preservatives4 ,the quantity used should be determined by the flavor desired and upon no other consideration4 ,the spices may be used whole1 ground1 or in some cases as acetic acid or oil extracts4 ,the whole spices are preferred by nearly all the manufacturers of high grade goods4 ,they are more expensive1 but give a different flavor from the extracts4 ,the spices are weighed for each batch and are tied in a bag or placed in a wire basket and suspended in the kettle while cooking4 ,some use very large quantities and cook from only ten to twelve minutes in order to get a distinctive flavor4 ,this is very expensive1 as only a small quantity of the flavoring matter is extracted in such a short time4 ,one of the serious objections to the use of the whole spices is that they may darken the ketchup and also cause some discoloration in the neck of the bottle4 ,for that reason1 black pepper and allspice in particular are being discarded1 and oil of cloves is being used in part for the whole berries4 ,the grade of the spice will also have an effect1 the cheap stock being unsuitable for a bright clean product4 ,small quantities of ground cayenne pepper are used as a substitute for the black pepper4 ,acetic acid extracts of some of the spices are being used to a certain extent1 but they have a peculiar harsh flavor that makes them undesirable4 ,the oil extracts can be used to only a very limited extent1 as they impart a flavor suggestive of the drug store4 ,one method of making a nearly complete extraction of the spices is to place them in their proper proportion in vinegar a few weeks before the ketchup season begins and then add the spiced vinegar in the proper proportion to each batch4 ,the result is different from that obtained by cooking1 and the method is not recommended for first grade goods4 ,the waste of spices in the usual process of manufacture is indicated by some work done by ,mr4 ,h4 ,e4 ,bishop of the laboratory of the ,indiana ,state ,board of ,health4 ,he found that in making ketchup1 when the boiling was kept up for thirty minutes1 that only #bg4h per cent of the oil of cassia1 #aa4e of the oil of cloves1 and #cc4c per cent of the oil of allspice were extracted4 7,unpublished report47 ,paprica rosen1 ,hungarian1 or sweet paprika1 is used for coloring purposes1 though it parades as a spice4 ,this is a mild variety of ,capsicum annuum1 one of the species of the genus ,capsicum1 from which cayenne pepper is made4 ,the variety offered to manufacturers has a more intense red color and much less pungency than the ordinary paprika4 ,this paprika can be obtained as the bright fruit1 ground dry1 or in oil4 ,in the latter1 it is said1 that part of the capsicin is removed1 also that the oil sets the color in inferior material4 ,the oil is of a reddish-yellow color and the large number of globules and irregular masses serve to distinguish it from cayenne pepper4 ,it fulfills the claims of the importers--8coloring the ketchup1 not adding materially to the pungency1 and coming inside the laws in being one of the regular ingredients40 ,it requires just about sixteen times as much as would be required of ordinary paprika to get the same flavor4 ,considering the cost1 in the relative proportion required1 there can be little doubt of its real purpose4 ,it will conceal inferiority to ordinary observation in that it gives a red color where otherwise a muddy color might be present4 ,the color does not have durability1 and it is easily recognized under the microscope4 ,onions and garlic are added in varying quantities and may or may not be kept in the batch throughout the whole cooking period4 ,considerable difference in flavor is apparent with the length of time of the cooking4 ,chili peppers are also used in hot ketchup or cocktails4 ,vinegar is added to nearly all ketchup4 ,formerly the acidity was obtained from the fermentation of the tomatoes and the resultant acid was probably mostly lactic4 ,the flavor was different and not so agreeable4 ,a good cider1 grain1 or malt vinegar may be used4 ,most manufacturers prefer to use grain vinegar of ten per cent acidity1 as the volume required is less and interferes less with concentration4 ,for real flavor1 however1 this may not be the best4 ,lately1 glacial acetic acid has been substituted for vinegar1 a practice which can not be approved and which ought to be abandoned4 ,citric acid is also added by some4 ,vinegar is usually added near the finish of the batch1 as otherwise it attacks the kettle to some extent and a part is driven off in boiling4 ,experiments made by adding vinegar to pulp and evaporating to fifty per cent of its weight in twenty and forty minutes1 respectively1 show that in the former case the added acidity was decreased in almost the same proportion as the total evaporation1 but in the latter case the acid was not driven off quite so rapidly as the moisture4 ,this does not correspond with views held by chefs1 as most of them seem to believe that practically all the vinegar is driven off4 ,in order to obtain the sterilizing effect of boiling in an acid medium1 it is advisable to make this addition at least five to ten minutes before the end of the cooking period4 ,in home-made ketchup1 vinegar is usually added near1 or at1 the start1 and aids in sterilizing the product1 as boiling alone may not1 whereas1 boiling in the presence of an acid will1 sterilize4 ,oil is not an essential to ketchup1 and while a small quantity is often used to prevent foaming1 its use in large quantities is undesirable4 ,sugar is added to give the desired flavor4 ,the higher the acidity1 whether natural1 or acquired by adding vinegar1 the greater the quantity of sugar needed4 ,in the high grades of ketchup1 granulated sugar only is used1 but in the cheaper grades1 soft sugar or glucose1 may be used1 though the latter must be declared on the label4 ,the sugar is usually added when the cooking is about one-half completed4 ,there is an advantage in heating both the sugar and vinegar in a separate kettle and adding them while hot1 as it will prevent a check to the cooking and lessen the sticking to the coils or kettle4 ,salt is used in small quantity and is added near the close of the cooking process4 ,the use of flour or starch in any quantity for the purpose of making the body thick or heavy is properly regarded as an adulteration4 ,this is also true of pulp from a foreign source1 like pumpkin or apples4 ,the density of the ketchup is left usually to the judgment of the chef1 who depends upon the appearance as it pours from the ladle4 ,a quick test can be made by weighing1 as done for pulp1 but in this case each manufacturer must determine his own standard4 ,a ketchup having specific gravity of #a4jij is apt to be thin2 a satisfactory consistency is usually about #a4abj to #a4adj4 ,as soon as the cooking is completed1 the ketchup is run through a finishing machine to remove all hard particles of tomato1 bits of spice1 etc41 and to give smoothness to the product by breaking it up into very small particles4 ,there are two types of finishers1 the shaking sieves and the rubbing machines4 ,the former is suitable for thin ketchup4 ,the resultant product gives the best possible appearance under the microscope1 the tissue showing whole cells1 little tearing1 and the minimum amount of debris and mold filaments4 ,the objections to the sieve are that the capacity is small and the waste is comparatively large4 ,the rubbing finisher needs to be very carefully adjusted1 otherwise it forces practically everything through in a very finely comminuted state4 ,the cells of the tissues are torn to shreds1 their contents discharged1 molds are broken into hundreds of fragments1 and a ketchup may be made to have the appearance of being made from poor material4 ,the finishers have large capacity and will work on either light or heavy goods1 but like the cyclone1 must be handled with judgment1 not attempting to force the last ounce through the sieve4 ,,bottling4 ,only new bottles should be used and these should be thoroughly rinsed before using and preferably with hot water4 ,since new bottles have no tightly adherent particles on the inside1 the use of clear water is sufficient1 dependence being placed upon the after process to insure sterilization4 ,the bottling should be done at as high temperature as is practicable1 about #afe to #agj degrees ,f4 ,if the temperature is higher than this1 the possibility of burns in handling is increased1 and too much space is left in the neck of the bottle after corking1 due to shrinkage of the ketchup on cooling1 and if much lower1 the expansion in processing causes excessive loosening of caps or corks and breakage4 ,furthermore1 when low temperature is used1 it requires a very long time to heat the contents of a bottle in pasteurizing4 ,a ketchup is a very poor conductor of heat and the heavier the body1 the longer the time that is required4 ,the closure may be made with either corks or seals1 the recent improvements in the latter making them much safer than they were a few years ago4 ,,processing4 ,after the bottles are sealed1 they should be given a process to insure sterility1 the time being about fifty minutes for half-pints and an hour and fifteen minutes for pints--or sufficient time to insure #aij degrees ,f4 for twenty minutes at the center of the bottle4 ,this step is omitted by many manufacturers1 dependence for sterilization being placed upon washing the bottle and subsequent heating for about twenty minutes4 ,the heating is accomplished by conveying the bottles through a chamber containing numerous steam pipes at high temperature and discharging them at the bottling machine4 ,it is assumed that sterilization of the ketchup has taken place in process of manufacture1 and the heat within the bottle will care for any infection which may possibly have taken place at a later time from the cap or cork4 ,the safety of this measure depends upon using a fairly acid ketchup or one with a heavy body4 ,it is a risky procedure for mild or thin ketchup4 ,it is a common occurrence to have the stock keep apparently while in the bottle1 but spoil shortly after opening4 ,the spoilage after opening is most often due to forms which have been present since manufacture and only need the presence of air to start growth1 and are not due to infection from the air4 ,a ketchup will inhibit the growth of organisms which gain entrance from without1 while those which are present but held in abeyance through exclusion of air1 will sometimes grow4 ,the writer has samples of ketchup put up in #aijf which apparently are sterile1 but which will show spoilage within a few days after opening1 though done under sterile conditions1 and the spoilage be identical in kind with that observed soon after manufacture4 ,how long these organisms will remain alive is not known4 ,in canning1 no foods are considered safe without processing1 and the same principle is a good one to follow with ketchup4 ,processing may be accomplished in open tanks1 in retorts1 in specially constructed pasteurizers1 such as used in the brewing industry1 and in hot chambers1 the method is not material1 though there may be considerable difference in point of economy4 ,,factory ,,arrangements4 ,the making of ketchup is simple and the factory arrangement for doing the work should be as compact as possible1 so that after the pulp is once heated1 there is an advantage in having the various steps follow in succession by gravity rather than be conveyed by pumps1 especially in small plants4 ,the piping should be as short and direct as possible4 ,the machinery for filling bottles1 corking1 etc41 leaves much to be desired2 as separate units they work fairly well1 but there needs to be some method devised for handling the bottles automatically from the time they are placed on the washer until they are labeled1 ready for the box4 ,at present the time between turning the crate of tomatoes upon the sorting belt until it is ready for the box is only slightly over two hours4 ,further improvement will not be so much in shortening the time as in eliminating the hand labor4 ,the foregoing description applies to the making of unfermented1 non-preservative ketchup1 made from sound stock and delivered into the bottle4 ,very little ketchup1 comparatively speaking1 is sold to the consumer in any package other than the bottle4 ,it can be delivered into the bottle when first made1 at less expense for labor1 with less fuel1 and with distinctly less waste than at any subsequent time4 ,it will have a better color and consistency than if stored in bulk and bottled later4 ,it is1 therefore1 advisable to bottle as much as possible at the time it is made4 ,ketchup may be packed in bulk in jugs1 tin cans1 and in barrels1 but not satisfactorily2 the jug is a poor package2 the enamel may be dissolved off the tin can and pinholes form2 and the barrel always gives a poor color and off flavor4 ,the best container for bulk ketchup is the gallon glass bottle4 ,,pulp ,,stock4 ,during the height of the season1 it may not be possible to convert all the tomatoes directly into ketchup1 in which event the surplus may be made into pulp4 ,the first part of the operation is identical with that already described4 ,the concentration is carried just far enough so that subsequently by slow heating for spicing it will give the proper consistency when made into ketchup4 ,a standard has not been fixed1 but tentatively it has been proposed that it be at about a specific gravity of #a4jce4 ,the concentration may be carried further and water added at the time of the final cooking1 but when this is done1 the resultant product does not have the same smooth consistency that is obtained by using the thinner pulp4 ,heavy pulp is made for the purpose of economizing in cans1 but experience has shown that economy does not always follow4 ,the higher the concentration1 the higher the acid content1 and this may attack the enamel and metal with resulting bitter flavor and frequent pinholes4 ,some manufacturers who prepare their own pulp carry the concentration between #a4jcj and #a4jcc4 ,the method of obtaining this density is to use flasks graduated to hold #ejj or #ajjj grams of water at #bjj degrees ,f41 fill them with the hot pulp and weigh at once4 ,for each flask there should be a proper counterpoise1 and the balance be sensitive and weigh in grams4 ,if the #ajjj-;gram flask be used1 the specific gravity will be the same as the weight of the pulp4 ,with a valve funnel the flask may be filled level full and the weight taken in less than thirty seconds4 ,for cold pulp1 a similar flask is used1 but graduated at #fj degrees ,f4 and after filling1 the flask is set in a sling and whirled a few times to free it from bubbles1 filled again to the level1 and then weighed4 ,for pulp of a specific gravity of less than #a4jcg1 this gives fairly concordant results1 but the errors increase rapidly the higher the concentration4 ,the same methods may be employed on ketchup4 ,recently1 ,w4 ,d4 ,bigelow has improved the apparatus by using a copper flask and adding a handle by which the flask may be submerged in the kettle to take the sample and thus prevents the entrance of air4 ,the use of flasks of any size is described in ,bulletin ,no4 #c1 ,national ,canners' ,association4 ,the use of the specific gravity method only partly solves the question of standardization4 ,two pulps each of #a4jce may vary considerably in what the chef terms body and there is no method of accurately measuring this factor or expressing it4 ,pulp made by draining will be lighter in weight with the same body1 and that from skins and cores will be rough or have the appearance of separating into small flakes or lumps4 ,the specific gravity bears a close relation to the soluble solids1 and as these do not have a constant ratio to the fiber in whole fruit1 and as the ratio is further disturbed by drainage and in the use of trimmings1 it is obvious that the method will not give an exact standard4 ,pulp should be filled into gallon or five gallon cans as hot as possible and sealed at once4 ,the practice followed by some manufacturers is to steam the cans first1 then depend upon the heat in the pulp to sterilize4 ,the cans are allowed to stand hot for forty minutes1 then cooled4 ,the other practice is to give the hot cans a process of about twenty minutes for gallons1 forty minutes for five gallons1 and then to cool4 ,cooling is essential to retain color and flavor1 as prolonged heat causes 8stack burning10 producing a brownish color and a bitter taste4 ,the highest grade pulp can not be held in barrels for the reason that the heat is retained too long4 ,stack burning will take place in glass if the packages are not allowed to cool well in the air before being stored1 though the changes are not so marked as in the tin4 ,,pulp ,,from ,,trimmings4 ,the losses in stock from canning tomatoes amounts to about forty per cent4 ,this is due to the unbusiness-like attempt to can all kinds--very large1 very small1 and wrinkled1 which can not be peeled with economy--to wasteful methods of peeling1 and to excessive draining of fruit from handling in too thick layers4 ,in this waste there is much that has good food value and which might be worked up into pulp or ketchup stock if properly done4 ,in order to do this1 the tomatoes should be sorted so that only those which are in perfect condition for canning will go to the peelers4 ,these should be medium sized1 firm1 evenly ripened all over1 and free from wrinkles4 ,such tomatoes can be peeled at the minimum of expense and loss4 ,the sound tomatoes which are small1 excessively large1 wrinkled1 or with green butts1 can go in with whole tomato stock4 ,the loss in peeling will then be small and can advantageously be discarded4 ,if it be decided to use trimmings from the peeling tables1 provision must be made for extra washing1 as the ordinary washer removes little more than the coarse dirt and particles1 is not sufficient for unusual conditions or to remove tightly-adhering material1 and1 furthermore1 rot must be eliminated before the tomatoes go to the peelers4 ,the writer has never seen a group of one hundred1 or any number1 of peelers who will stop to trim and separate rot from peels and cores4 ,trimming can be done better by a few when sorting the tomatoes than at any subsequent step4 ,if clean skins and cores can be had from the peeling table1 they can be converted into pulp and sold if labeled properly1 8from trimmings40 ,whether such waste is suitable for a good product depends upon how it is handled4 ,for the most part1 it has not been handled as well as it should be4 ,the finished pulp made from skins and cores is not the same as that from whole stock4 ,it contains more fiber1 remains more or less lumpy1 and lacks the smooth body of whole pulp4 ,the color is not so good1 and the flavor is likely to be somewhat different4 ,the flavor of the seed cells and that of the fleshy portion of the tomato are different4 ,pulp made from each part separately shows marked difference1 that from the seed cells being poor in color1 but with the more characteristic fruit flavor4 ,tests show that neither part has any true jellying powers1 but that the part from the seed cells gives the quality of smoothness1 the holding together of the particles of solids4 ,neither gives a first class pulp alone4 ,,color4 ,home-made ketchup generally has a rather dark reddish or brownish color1 due to prolonged heating1 made necessary under kitchen conditions4 ,at one time this was thought desirable and some of the older recipes call for the use of caramel in order to imitate this color4 ,most manufacturers now aim to secure a clean1 clear color1 preferably bright red4 ,this may be obtained when good fruit is used and handled quickly2 a muddy brownish or yellowish color is looked upon with suspicion as indicating poor material or defective methods4 ,the necessity for a clear red variety has already been pointed out1 for without proper stock1 a superior product of uniform quality can not be made4 ,the tomatoes must be well vine-ripened1 as the presence of green fruit and green butts has a decidedly dulling effect4 ,colorimeter tests show that the use of even small quantities of green material have an immediate dulling effect4 ,promptness in handling the fruit after the tissue is once exposed to the air is also essential4 ,the tomato1 like some other fruits1 turns brownish when the surface is cut or exposed4 ,this does not occur as rapidly1 nor is it so marked as in apples or in pears1 but it is present4 ,when the tomato is converted into pulp1 every particle is exposed to the air for a very short time--long enough to make some slight change4 ,the change is most marked in pulp from raw stock and least in that which has been well heated4 ,it naturally follows that ketchup made promptly from whole stock will have the best color1 that from canned tomatoes next1 then canned pulp1 and lastly1 that from trimming stock4 ,pulp allowed to stand hot for too long a time will have a brownish color like stack burning4 ,when barrel pulp was used1 this was ascribed to the tannin extracted from the oak4 ,pulp should not come in contact with iron at any stage1 as the union of the acid of the fruit with the metal will cause discoloration4 ,when such discoloration does occur1 it becomes uniform throughout the mass1 and not in the neck of the bottle as has sometimes been described4 ,darkening in the neck of the bottle is frequently due to the spices used1 as has already been pointed out4 ,it can be redistributed throughout the whole by placing the bottle in a shaker for a short time4 ,darkening at the top may sometimes be due to extraction of color from the corks4 ,soaking corks in two per cent acetic acid1 then in hot water before drying1 and paraffining1 will assist in preventing discoloration on cheap grades4 ,discoloration in the neck also results from the small amount of air incorporated and from any subsequent addition which may come in through the cork or seal4 ,bottles which are full to the cork may show no darkening1 those having a space of an inch or more between the contents and cork may show little discoloration1 while those having more space will show much more marked discoloration4 ,this holds for both pulp and ketchup and in this case the discoloration begins on the surface and works downward4 ,the product made from some fruit will discolor more than that made from fruit grown in another section of the country4 ,a bright red color is secured in some brands of ketchup by means of paprika1 as indicated under spicing4 ,a light colored ring in the bottom of a bottle is generally due to organisms and debris1 indicative of the use of barrel or trimming-stock pulp1 or it may result from changes after the process of manufacture4 ,it has been mistaken for sand4 ,,keeping ,,quality4 ,ketchup must not only keep while in the unopened bottle1 but for a reasonable time after opening1 if it is to be a commercial success4 ,every canner understands that if he puts food in a hermetically sealed package and sterilizes by heat1 that it will keep until opened4 ,the same principle applies to ketchup in the bottle1 but there are some packers who wish to be spared this expense and trouble and prefer to use a substitute for heating4 ,the keeping quality after opening depends upon the utilization of the same principles followed in the household operation of making fruit butters1 ketchup1 preserves1 and pickles1 that is1 sufficient concentration and the use of sugar and vinegar4 ,a ketchup can be made essentially a pickle with an excessive quantity of vinegar and it will keep2 it can be made a preserve with excess of sugar and it will keep2 or1 it can be made a distinctive sauce well concentrated in which the vinegar and sugar are used only in sufficient quantity to give proper flavor1 and it will keep4 ,apple juice or cider will spoil quickly if allowed to stand in a warm place2 apple sauce will behave in like manner only a little more slowly2 but if the juice and sauces be boiled together until they have acquired the consistency or state known as apple butter1 they will keep very well4 ,the acidity1 sugars1 and solids have been increased by the concentration4 ,in the making of tomato ketchup1 the fruit does not have sufficient acidity and sugar of itself to give preservative property at the concentration desired for a sauce1 so these are augmented by the addition of vinegar and sugar4 ,a great deal of stress has also been placed upon the effect of the spices in acting as preservatives4 ,experiments have demonstrated conclusively that when these are used in the small quantities required for flavoring1 that their effect is practically nil4 ,the active principles of the spices are effective only when present in the proportion of #a to #ejj or #fjj and in ketchup the proportion is only #a to several thousand4 ,likewise the quantity of salt is too small to have effect4 ,the keeping qualities of a mild ketchup will depend far more upon the sterilization than most manufacturers realize4 ,it is easy to make almost any ketchup apparently keep while the bottle is unopened4 ,the spoilage after opening is most often observed to be due to mold which has been assumed to come from infection from the air4 ,as a matter of fact1 this is nearly always due to spores which have been held in abeyance1 due to lack of air while in the bottle1 and which begin growth as soon as conditions are favorable4 ,spores which fall into the bottle from the air might be unable to germinate upon such a medium1 while those already present would4 ,,characteristics ,,of ,,commercial ,,ketchup4 ,while tomato ketchup is a complex and variable product1 its general composition may be determined with a fair degree of accuracy4 ,inspection will give a good idea of color1 consistency1 smoothness of body1 fineness of finish1 tendency to separate1 presence of objectionable particles1 and evidence of gross fermentation4 ,the odor and taste will give a clue to the kind and quantity of spices used and to a certain extent the character of the raw material4 ,judging by odor and taste is not so well done as judging by the eye by most persons4 ,the education of those two senses has been neglected and therefore fail to give all the information which might be acquired in this way4 ,a chemical examination which will give the specific gravity1 total and soluble solids1 sugar1 salt1 and total and volatile acidity1 will be sufficient to give a good idea of the stock used--tomato1 salt1 sugar1 and vinegar1 but not the spices4 ,a microscopic examination will assist in determining the condition of the material used and whether decomposition has taken place before or after manufacture4 ,the facts obtained through these sources will permit of classifying commercial ketchup with a fair degree of accuracy4 ,there has been a very marked change in the character of ketchup since the transition from the preservative to non-preservative goods1 not only microscopically1 but also in composition4 ,formerly1 there were very many brands of thin liquid ketchup1 showing little concentration of pulp1 very low in sugar1 and having only small quantities of vinegar2 the standard was bulk rather than quality4 ,the microscopic examination also showed that the product had frequently undergone change before and after preparation4 ,recent examinations show that there has been a very marked improvement2 that the body is decidedly heavier1 more sugar and vinegar are used1 the tissue is cleaner1 and there are fewer organisms present1 also that the difference in composition in preservative and non-preservative ketchup is small1 whereas1 formerly it was marked4 ,the variations found in ketchup of rather recent examination show in the non-preservative kind the specific gravity varied between #a4jia and #a4agg2 the solids between #ai and #cg per cent2 the salt between #b and #d per cent2 sugar between #ab and #bi per cent2 and volatile acids between 4#ed and #a4bd per cent4 ,in the preservative kind1 the specific gravity ranged from #a4jcb to #a4abj2 the solids from #i4bc to #bh per cent2 salt1 #a4dh to #c4d per cent2 sugar1 #d4ie to #af4i per cent2 and volatile acidity1 4#af to 4#fd per cent4 ,as a class they averaged lower in concentration of tomato and in sugar and vinegar1 though if proper sterilization had been used1 some of them would have kept without difficulty4 ,in experimental work it was found that a ketchup concentrated so that when finished it showed an added sugar content of #ae per cent or more1 a total acidity of #a4b per cent1 and a specific gravity of #a4abj or more1 that it would keep4 ,to obtain a total acidity of #a4b per cent means the addition of about 4#d to 4#f per cent acidity in the vinegar used4 ,however1 there are brands of ketchup on the market which keep well after being opened and which have a total acidity of less than #a4j per cent4 ,the manufacturer can use the following as a starting point for non-preservative ketchup2 pulp1 #ajj gallons2 sugar1 #fj pounds2 salt1 #h pounds2 vinegar1 #ajj grain1 #b gallons2 spice to flavor2 and concentrate to #ej to #ee gallons4 ---------------------------------------- -------------------------------- ,,microscopic ,,examination4 ,a discussion of the microscopic appearance of ketchup in terms which can be readily understood by manufacturers is not an easy task1 as it necessarily involves technical knowledge4 ,the subject has become one of importance1 owing to the attitude of many food officials in enforcing a microscopic standard for this product1 and on the part of many brokers in requiring a guarantee to comply with this standard in making purchases4 ,many manufacturers have either assumed or found it necessary to have their finished products examined4 ,some employ 8experts0 to make the examinations in their own plants1 while the majority send their samples to commercial laboratories4 ,the total tax upon the industry for such work amounts to thousands of dollars annually4 ,the result of the work as a whole has been beneficial1 as any effort is which attracts attention to details4 ,it has likewise been the means of causing much unpleasantness and not infrequently loss1 because of lack of understanding on the part of both manufacturer and examiner as to the cause of certain findings4 ,the manufacturers have proceeded in the usual way without sufficient knowledge of what the resultant product will be unless there is careful supervision of material and methods1 while too frequently the examiner is neither experienced in technique of the examination nor in the effects of the different steps in manufacture upon the product4 ,furthermore1 much distrust in microscopic finding is evinced when a half dozen or more samples from the same batch1 sent to as many persons1 result in as many different reports4 ,it naturally causes a lack of confidence in both paid examiners and in food officials1 though those who make these examinations may be absolutely honest in their findings4 ,in order to clarify some of the points1 it has become necessary to go into detail1 into both the method of examination and into the effect produced by manufacture4 ,a scientific method of food examination is necessary for food officials in order to determine the condition of a product1 but is not necessary for the manufacturer1 though it may be advantageous4 ,the latter is in a position to know what enters his factory and what changes take place in the food until it reaches the sealed package4 ,he should have no fear of a method which correlates the findings in the finished product with that of the material used and the changes due to treatment4 ,undue importance may seemingly be given to the subject of ketchup1 but the principle involved applies as well to other products4 ,the fundamental basis for the microscopic examination of any food product must depend upon the structure of the material which enters into its composition4 ,any attempt to determine an abnormal condition1 such as decomposition1 without a knowledge of the normal1 must necessarily be of little value4 ,there is some work which can be done in a mechanical manner by almost anyone capable of looking through a microscope1 and if the work is properly supervised1 it may have a value1 but the lines along which this can be done are very limited4 ,any attempt to apply such superficial methods to the general examination of food products can not properly protect the public and may be unfair to the producer4 ,it has1 therefore1 been deemed advisable to incorporate a brief statement concerning the structure of the tomato before discussing the resultant products4 ,,histology ,,of ,,the ,,tomato ,,and ,,of ,,the ,,resulting ,,ketchup4 ,,structure ,,of ,,the ,,tomato4 ,pericarp4 ,the tomato is a typical berry1 the ovary wall1 free from the calyx1 forming the fleshy pericarp1 which encloses chambers filled with a clear matrix1 containing the seeds4 ,the pericarp consists of an outer tough membrane1 the epidermis1 a more or less thick layer of parenchyma tissue1 the pulp1 and an inner thin1 delicate membrane1 the lining layer of the loculi or chambers in which are the seeds4 ,the epidermis consists of a single layer of cells which have a very thick continuous cuticle about one-half of the diameter of the whole cell4 ,the cuticle differs in chemical composition from the rest of the cell walls1 being impervious to water1 and resisting rotting longer than do the cellulose walls4 ,as it is continuous over the whole of the fruit1 the skin can be readily separated from the other tissues4 ,hot water facilitates the removal of the skin1 as it causes the cellulose of the walls to swell more than the cuticle1 producing an effect as of shrinkage of the outer wall and a consequent curling of the skin4 ,the radial walls of the epidermis are short and irregularly thickened1 leaving pits in the walls1 and giving them a beaded appearance4 ,the skin constitutes about #a4c per cent of the tomato4 ,the layers of parenchyma just beneath the epidermis are closely united and flattened1 with their adjoining walls irregularly thickened4 ,on account of their position1 they are called hypoderm4 ,in the tomato the hypoderm consists of two or three layers of cells1 parts of which usually separate with the epidermis4 ,below these cells are the thin-walled parenchyma cells1 which are approximately globular1 vary considerably in size1 are very loosely held together1 and have many intercellular spaces4 ,these cells constitute the mass of the pulp1 and with the juice constitute #if4b per cent of the tomato4 ,the layer of cells which lines the chambers has the typical leaf epidermal structure1 the wavy outlines1 the hollows and protuberances of adjoining cells fitting one another so that they form a continuous layer4 ,they are also flattened laterally4 ,the structure can be understood readily when it is known that the pericarp is really a metamorphosed leaf and that the outer side of the leaf forms the inner wall of the ovary4 ,the chambers of the tomato are filled with a clear1 slimy matrix in which the seeds are embedded4 ,the matrix consists of parenchyma cells of various sizes and with delicate walls1 and a small nucleus4 ,the cells are massed loosely1 and can be separated readily4 ,in those cells1 as well as in the wall cells1 are starch grains which vary in size1 being round or approximately so1 and having the hilum1 when visible1 a straight line to one side of the center4 ,coloring ,matters4 ,in the parenchyma cells are two coloring matters1 one yellow1 which is amorphous in structure1 and the other red and of crystalline form4 ,the sap contains a yellow color in solution which differs in its reactions from those in the pulp4 ,red ,color in ,tomatoes4 ,the red coloring matter in tomatoes is in the form of irregularly shaped crystal-like chromoplasts1 which occur in masses of various sizes4 ,they are present in largest amounts usually in the protoplasm which lies close to the ectoplasm and in that surrounding the nucleus4 ,they vary from sharp1 bright-colored forms to those more or less blunt in outline1 and dull in color4 ,they may be situated largely in the periderm1 the soft parenchyma beneath the periderm1 or through the whole mass of the parenchyma with the exception of the matrix surrounding the seeds in the loculi4 ,in tomatoes having the color in the periderm a considerable amount is lost by adherence to the skin4 ,the chromoplasts are not affected by rotting to the same extent as are the other constituents of the cell2 they can be found floating free in the debris from rotted cells1 still retaining considerable color4 ,they lose their color gradually1 in some varieties much more rapidly than in others4 ,in stored pulp which has fermented1 the color may be faded to a dull yellowish brown4 ,in tomatoes intended for ketchup where a bright red color is desirable1 care should be used in the selection of a variety having the chromoplasts bright1 properly oriented1 and in sufficient quantity4 ,vascular ,bundles4 ,in the pulp of the tomato are found strands of vascular tissue1 entering from the stem1 and dividing and ramifying through the soft pulp4 ,these consist of long tubes with thin walls1 some of which have a strengthening band in spiral form on their interior walls1 the associated cells being without any special marking4 ,the strands vary in size from those having a few tubes to those having a large number4 ,seeds4 ,the seeds of the tomato are small1 flattened1 yellow bodies covered by a clear gelatinous membrane4 ,their peculiar characteristic is the out-growth of hairs of varying lengths4 ,the seeds constitute about #b4e per cent of the weight of the tomato4 ,,structure ,,of ,,ketchup4 ,although the tomato pulp is broken into fine particles by the action of the cyclone1 and the skin and seeds are removed by the fine sieves1 pieces of the various tissues can be readily identified4 ,the skin and seeds have characteristics which would serve to distinguish them from similar parts of other vegetables which might be used for adulteration1 but particles of skin and hairs from the seeds are rarely found4 ,the distinctive features which can be relied upon are the red1 irregularly-shaped1 chromoplastic bodies in the parenchyma cells1 and the peculiar wavy-outlined cells of the lining layer of the chambers4 ,as nearly all young vegetable tissues have spiral vessels in their vascular strands1 these are not distinctive1 except that they might differentiate similar tissues of different size4 ,there is very little starch in mature tomatoes1 and moreover1 as the cooking causes the starch to swell and lose its structure1 the starch could not be used for identification4 ,good ketchup made from whole tomatoes1 in spite of the minuteness of the particles1 has a clean appearance1 and can be readily distinguished from poor ketchup4 ,all ketchup will have some micro-organisms present1 as it is practically impossible to free the tomatoes from them in the washing1 but the number is very small in some of the best1 in the manufacture of which careful washing and sorting have been done4 ,the poorer the ketchup1 usually1 the greater number of organisms--bacteria1 yeasts1 and molds2 sometimes one form predominating1 sometimes all three being in great abundance1 this latter condition usually prevailing in the poorest ketchup1 where more or less rotting has occurred4 ,as the tomato pulp is a favorable medium for certain organisms1 these will develop first1 and it has also been determined that while one organism is developing vigorously1 others present are checked until the activity of the first ceases4 ,then again1 as the composition of the pulp is being altered by the development of the organisms1 the changes induced render it a more suitable medium for other organisms which are present but held in abeyance1 so that pulp which has been allowed to stand for some time will usually have present not only a large number1 but also different kinds of organisms4 ,,changes ,,produced ,,in ,,pulp ,,by ,,rotting4 ,when tissue is held and allowed to rot spontaneously1 the pulp is decomposed into a granular1 watery mass4 ,the cells beneath the epidermis are the finest and driest in the sound tomato1 considerable pressure of the cover-glass being required to separate them for examination4 ,even when forced apart1 the cells retain their shape4 ,they contain a delicate semi-transparent protoplasm with a rather large nucleus surrounded by protoplasm and having strands from this mass connect with the protoplasm lining the wall4 ,pieces of the same tissue1 on having the skin removed so as to expose the broken tissue to the air1 were covered with mold in one day and in three days so badly disorganized that the cells separated with the weight of the cover-glass4 ,the cells were transparent1 the walls collapsed into a wrinkled mass1 the protoplasm had disappeared1 except a skeleton of the nucleus1 but the red chromoplastic masses were intact4 ,the middle lamella of the cells is the part which dissolves first1 allowing the cells to separate and causing the walls to become thinner4 ,the cell cavity is often filled with bacteria1 so that the effect of the rotting can not be seen until the cells have been washed thoroughly4 ,these bacteria have been mistaken for the particles left by the decomposition of the cell contents4 ,the vascular bundles are surrounded usually by small parenchyma cells which do not separate readily from the strand in the healthy tissue1 but in the decayed tissue the vessels can be seen clearly1 free from other tissue4 ,in advanced stages of rottenness the walls of the vessels may be dissolved1 leaving only the spiral thickening1 and the parenchyma tissue crumbled into powder-like fragments4 ,the parts of the tomato which resist rotting the longest are the skin1 which may be washed clean of adhering particles1 the spirals of the vessels1 and red particles of the chromoplasts4 ,the conditions found in the rotted sections and pieces of tomato can be distinguished in the poor ketchup and these factors1 together with the large number of organisms present1 serve for purposes of differentiation4 ,,organisms ,,in ,,ketchup4 ,tomato pulp furnishes a medium suitable for the development of many organisms1 as it contains all of the necessary food elements4 ,the raw pulp has an acidity of from #j4b to #j4d per cent usually1 though there may be variation due to fermentation and other causes4 ,on account of its mild acidity1 it is especially suitable for the development of many yeasts and molds1 and some forms of bacteria1 consequently there is present a varied and abundant flora if the pulp be held for an appreciable time before using1 or if it has been made from tomatoes not properly sorted and washed4 ,where the black rot occurs on tomatoes1 the tissue is hardened like cork1 and if not removed on the sorting belt1 is broken into small pieces by the cyclone1 and appears as black specks in the ketchup1 these being readily perceived by the naked eye4 ,the white rot forms soft spots1 which1 though not so prominent as the black1 carry much more contamination1 as1 apart from the bacteria1 yeasts1 and molds present1 they are often swarming with ,protozoa4 ,these are not ordinarily recognized in the ketchup1 as a chemical or physical shock causes them to contract1 assume a spherical shape1 and become motionless4 ,in this condition they resemble the immature conidia of some of the molds4 ,rarely only one organism predominates in pulp from rotted fruit1 then the rot consisting of a nearly pure culture4 ,in all cases of soft rot1 there is much more contamination carried1 as the organisms are small and a greater number present in a given area4 ,whenever the inner tissue of tomatoes is exposed1 organisms develop rapidly1 the forms varying with the locality and the conditions in the pulp4 ,some of these organisms may survive the treatment of the pulp when converted into ketchup1 or the original organisms may be destroyed1 and a different set gain access and develop1 but in either event all the organisms alive or dead which were present at the period of manufacture are found in the ketchup4 ,it has been noted that certain brands of ketchup have predominating organisms present which are practically constant from year to year4 ,a method for the microscopic examination of ketchup in order to determine the number of organisms present is described in ,circular ,no4 #fh1 ,bureau of ,chemistry4 ,it consists in an adaptation of a method used in examining blood in physiological and pathological work1 and of yeast in the brewing1 wine-making1 and distilling industries4 ,the outfit required consists of two parts1 the microscope and the counting chamber1 each with minor accessories4 ,the optical outfit recommended for food examination consists of a microscope with eye pieces and objectives which will give approximate magnifications of #ij1 #ahj1 and #ejj diameters4 ,it is advised that these magnifications be obtained by using #af mm and #h mm apochromatic objectives1 and #f and #ah compensating oculars 7#f ocular and #af mm objective equals #ij2 #f ocular and #h mm objective equals #ahj2 and #ah ocular and #h mm objective equals #ejj71 higher objectives being impracticable on account of their short working distances4 ,this equipment is adequate for working upon blood or yeast1 but is wholly inadequate for bacteriological work1 except that of the simplest character and under conditions quite different from those found in ketchup and other food products4 ,the counting apparatus or chamber recommended is known as the ,thoma-,zeiss haemacytometer1 named from the designer and maker4 ,the apparatus consists of a heavy glass slip1 on which is cemented a glass #j4b mm thick1 having a circular hole in the middle4 ,in the center of the hole is mounted a smaller disk #j4a mm thick1 leaving an annular space4 ,in the middle of the small inner disk are etched two sets of twenty-one parallel lines which cut each other at right angles4 ,the drop of liquid to be examined is placed on this square1 after which it is covered with a specially heavy cover-glass1 which1 if perfect and adjusted so closely that ,newton's rings appear1 gives a layer of liquid #j4a mm in depth4 ,the drop to be examined must be so small that it remains in the middle of the chamber1 but in contact with the cover-glass and bottom of the cell4 ,each side of the ruled square is #j4a mm1 and as there are #bj spaces on a side1 there is a total of #djj small squares1 the depth being #j4a mm1 thus the cubical content of each is #a-d1jjj c mm or #a-d1jjj1jjj cc4 ,for convenience in counting1 every fifth space is sub-divided4 ,other counting chambers have been devised based on the same principle1 but varying chiefly in their rulings for convenience in counting4 ,the other apparatus recommended consists of a #ej cc graduated cylinder1 slides1 and cover-glasses4 ,since the counting chamber has been used extensively in blood examination and in yeast work1 a brief description of the technique as followed in the latter may serve to give a better understanding of its limitations4 ,first1 in the preparation of the sample1 the cylinder and flasks for mixing1 and the pipette must be absolutely clean4 ,the liquid to be examined is shaken thoroughly and then the measured sample withdrawn as quickly as possible to prevent the cells from settling and diluted with weak sulphuric acid 7about #aj per cent71 which prevents any further development of cells1 and also aids both in the separation of the cells from one another and in their suspension--the latter factor being important when only a single drop is taken for examination4 ,when counting blood cells1 a normal or other salt solution is used so as to have the specific gravity of the diluent approximately that of the blood serum4 ,the dilution is made as low as possible1 since the number obtained in the count has to be multiplied by the dilution co-efficient1 and any errors made are increased proportionately4 ,a slight error when multiplied by the factor #d1jjj1jjj1 the unit for each square1 becomes very large in the total4 ,the sample is shaken very thoroughly after the diluent is added1 a drop of the liquid taken by means of a pipette1 placed in the center of the counting chamber1 and the cover-glass put in place4 ,the withdrawal of the pipette and the transference of the drop to the chamber are done as quickly as possible to prevent the cells from sinking4 ,the determination of the number of blood corpuscles1 yeasts1 or other cells in one cubic centimeter1 the unit of volume generally used1 will depend upon the average found in a number of squares4 ,the number of squares to be counted is determined by making counts until a constant average is obtained1 for if a true average is not obtained1 the counting1 naturally1 is of no value4 ,if the mounts do not show uniformity in the field1 they are repeated4 ,in using the counting chamber for counting yeast cells and blood corpuscles1 for which it was originally devised1 the bodies to be examined are fairly large1 well defined1 and suspended in a fairly clear liquid1 usually of rather high specific gravity4 ,even with these favorable conditions1 the work must be done by observing the most careful technique in order to get relative results1 which will be of value1 and they are absolutely useless if any detail has been slighted or neglected4 ,in attempting to adapt the method to food products1 very different conditions are encountered--conditions which are opposed to obtaining accurate results4 ,food products1 like ketchup1 consist of a mixture of solids and liquids in which are various forms of organisms1 the latter in varying condition1 due to their environment and treatment1 as well as to stages of disorganization4 ,in estimating the number of yeasts and spores in pulp or ketchup1 the ,thoma-,zeiss counting chamber is used and the mount observed under a magnification of #ahj diameters4 ,to prepare the sample1 #aj cc of the material has #bj cc of water added and is 8thoroughly mixed40 ,before taking a drop for examination1 the sample is allowed to rest for a 8moment0 to allow the 8coarsest particles0 to settle4 ,this step in the technique is not as clear as could be desired1 for what might be considered as 8thoroughly mixed0 by one microscopist as a half dozen shakings of the cylinder1 might not be so construed by another even with sixty shakings4 ,as the material consists of both solids and liquid1 this is a very important detail1 as it may easily account for some of the wide differences in results obtained by different workers on the same sample4 ,in a bulletin#b dealing with the examination of solid foods1 the following statement occurs relative to the shaking in order to be able to obtain the bacterial condition3 8,the longer the shaking1 the more perfect was the diffusion of particles4 ,it could not1 however1 be continued beyond a comparatively short period of time1 because of the multiplication of organisms4 ,with the quantities of tissue above stated1 ten minutes' shaking was selected as a happy medium between an undesirable multiplication of the organisms on the one hand and the retention of the organisms by the tissue and the consequent lowering of the numbers found1 on the other40 ,the organisms in pulp or ketchup are dead1 or1 if alive1 do not possess such phenomenal power of multiplication1 therefore1 the shaking should be conducted with sufficient energy and for a sufficient time to insure their separation from the tissue4 ,furthermore1 8letting stand for a moment0 may mean thirty seconds or two or three minutes to different persons4 ----- ,footnote #b3 ,no4 #aae--;,bureau of ,chemistry1 ,dept4 of ,agr4 ,in all biological work involving the counting of organisms1 either by the plate or direct method1 in the case of yeast1 the operator works as rapidly as possible to prevent the organisms from settling1 so as to have them evenly distributed in order that he may obtain an average sample4 ,a pipette is used for removal of a drop of the liquid and the drop placed in the chamber as quickly as possible to prevent settling4 ,no directions are given as to how the drop of the diluted pulp or ketchup is to be removed to the chamber1 so that a stirring rod or other apparatus is frequently used1 as the solid particles interfere with the use of a fine pipette4 ,if the rod be inserted to the bottom1 or nearly to the bottom of the mixture and withdrawn slowly and another withdrawn somewhat rapidly1 a difference of fifty per cent or even more may result in the count4 ,it is not possible for different operators to use pipettes1 glass rods1 pen knives1 toothpicks1 and matches for drawing the samples1 and get comparable results4 ,it has been found that in 7all of these have been seen in use7 the counting of the organisms in pulp and ketchup1 some persons use distilled water1 others tap water1 some clean their measuring flasks and pipettes1 while others rinse them1 so that naturally reports are made of such varying numbers that manufacturers do not look upon the method with confidence4 ,it is only by using uniform methods and the same care necessary for other biological work that even an approximation can be made4 ,,structure ,,of ,,the ,,tomato4 ,to obtain the number of yeasts and spores in the sample1 a count is made in one-half of the ruled squares4 ,two hundred squares represent a volume equivalent to #a-bj c mm1 which1 multiplied by the dilution1 would give the number in #a-fj c mm4 ,it is stated that it is believed that it is possible for manufacturers to keep the count below #be per #a-fj c mm4 ,the same mount is used in estimating the bacteria1 but the #ah ocular used so as to increase the magnification to approximately #ejj diameters4 ,the 8number in several areas1 each consisting of five of the small squares1 is counted40 ,nothing is said as to the order of the five squares1 whether in a row or other arrangement1 nor what number constitutes 8several40 ,the average number found in five squares represents the number in #a-hjj1jjj part of a cc1 and this multiplied by #c1 for the dilution1 would make the factor #a-b1djj1jjj for a cc4 ,it is stated that it is believed that it is possible for manufacturers to keep within #ab1ejj1jjj bacteria per cc in the pulp and #be1jjj1jjj in ketchup4 ,the number present is expressed in terms per cc though the yeast and spores are expressed in #a-fj c mm4 ,possibly bacteria to the lay mind mean something dangerous1 so by expressing the numbers in millions they appear appalling4 ,yeasts and spores are not so generally associated with dirt and disease so that by giving them a small unit1 only #a-fj1jjj part of a cc1 they may seem much less offensive4 ,if the mind is capable of conceiving what is meant by millions per cc for bacteria in one case1 there seems to be no good reason why the same unit of volume should not hold for the other4 ,to estimate the number of molds present1 a drop of the undiluted pulp or ketchup is placed on an ordinary slide and the ordinary cover-glass pressed down until a film of #j4a mm is obtained4 ,the directions state that after some experience this can be done1 but do not state how one's efforts may be directed to obtain this result4 ,it is apparent that by experience in comparing a measured amount with a judged amount that the tendency would be toward accuracy1 but in this case there is no measured amount for comparison1 except the diluted drop in the counting chamber4 ,some workers have placed thin cover-glasses under the edges of the mount so as to have something to help in estimating the thickness of the film1 but as the thinnest ordinary cover-glasses vary from 4#ab to 4#ag mm in thickness1 the error varies #bj to #gj per cent from that required4 ,one manufacturer in advertising ,no4 #a cover-glasses states that they vary from #j4ac to #j4ag mm1 while another states they vary from #a-bjj to #a-aej of an inch 7#j4abg to #j4afi mm74 ,careful checks show that it is not always easy to get exactly 4#a mm on the specially prepared counting chamber2 that unless the cover be placed with care and pressed uniformly on all sides until ,newton's rings appear1 a variation of ten per cent or more in thickness may occur1 and without such a guide the error becomes greater4 ,the micrometer screw adjustment on the microscope can be used to help in determining the thickness1 but none of the workers observed has used this refinement4 ,the examination for mold is made with the #f ocular and #af mm objective1 giving a magnification of approximately #ij times4 ,about #ej fields are supposed to be examined and the result expressed in terms of the per cent in which mold was found4 ,it is stated that it is believed that manufacturers can conduct their operations so that mold will not be present in more than #be per cent of the fields4 ,there are1 therefore1 three units in which to express the results3 bacteria in cubic centimeters1 yeasts and spores in one-sixtieth of a cubic millimeter1 and molds in percentage of microscopic fields4 ,aside from the errors which may occur in the manipulation of the purely mechanical part of the technique1 there are other considerations which affect the accuracy of the results4 ,first1 the differentiation between organisms and tissues is not considered possible by most pathologists and bacteriologists without differential staining4 ,even in such simple examinations as those for diphtheria and tuberculosis1 a stain is required4 ,in foods the particles of the plant tissue and the organisms are not so different that they can be clearly separated without using similar technique4 ,it is possible to make some separation1 but not with accuracy4 ,threads of protoplasm may be mistaken for bacilli2 the granular contents of a cell for cocci1 yeasts1 or spores2 bits of cell wall for hyphae under the magnifications given1 and the results obtained be high or low1 depending upon the personal ability of the operator4 ,each error magnified by the enormous factor used in calculating the final result naturally gives figures which may be far above or below the truth4 ,those who have had special training in plant structure and bacteriology are likely to give the higher figures1 while those who have had these subjects as incidentals in a scientific course are apt to give much lower ones4 ,second4 ,the standard is set for what organisms shall be counted and those which need not be4 ,it is said that micrococci need not be counted because of the difficulty in distinguishing them from 8particles of clay1 etc410 and not upon their power to produce decomposition4 ,when an organism is a coccus and when rod shaped is not easily settled1 even with the aid of pure cultures and high power objectives4 ,more than one organism has found a home first in one group and then in the other1 and differentiation with the low power obtained by an #h mm objective is impossible4 ,there are always present some very large rods1 but there may be more very short ones which may not be counted1 and there is nearly always a diplococcus present1 which1 with the magnification used1 is difficult to differentiate from a rod4 ,there are four forms associated with rot and tomato diseases which have been carefully studied--all rods1 but very small ones4 ,ps4 fluorescence1 #j4fha4ag-a4hf2 ,ps4 michiganense1 #j4ce-j4dj4h-a4j2 ,b4 carotovorus1 #j4g-a4ja4e-e2 and ,b4 solanacearum1 #j4ea4e4 ,bacillus subtilis1 4#gb-h and some lactic acid forming varieties are always present4 ,it is clearly a matter of judgment on the part of the examiner as to which organisms he will count and which he will not attempt to count4 ,a personal equation is thus introduced which nullifies the possibilities of scientific accuracy4 ,the yeasts and spores are counted together4 ,they can not be separated under the microscope1 neither can they be differentiated from contracted protozoa which may be present in large numbers4 ,in counting these1 it is not always possible to distinguish the smaller yeast cells and smaller spores from the refractive bodies which are formed in some mold hyphae when these are impoverished1 and which are liberated if thorough shaking of the sample be done4 ,the yeasts found in pulp and ketchup are more likely to be 8wild yeasts0 and these are1 as a general thing1 smaller than the cultivated1 sporulate more readily1 and have more highly refractive spores4 ,then1 some of the so-called molds found form minute conidia and when these and the yeasts are mixed with the detritus of the tomato and the mass subjected to heat1 with the consequent changes1 the accuracy of the count becomes a somewhat problematical matter4 ,a careful examination of the kind and condition of the hyphae present might assist materially in making some distinction4 ,in counting molds1 no distinction is made as to whether a small bit is in the field or a large mass4 ,in making a mount for molds1 the solids generally tend to stay in the center of the field while the liquid tends to run to the edge4 ,the fields selected may therefore give a high or low result determined by their location4 ,one examiner desiring to favor the manufacturer may select the outer part for most of the fields1 while another1 making the examination for the buyer1 who may wish to make a rejection1 may reverse the operation4 ,some persons modify the directions given by counting only pieces which are one-sixth the diameter of the field1 while others use a smaller fraction4 ,it is easily possible to have one clump of mold in one field which will be twenty to thirty times in extent that of another1 yet both are given equal value in the final expression4 ,third4 ,no real relation exists between the organisms counted and decomposition1 for mere numbers are not always coincident with putrefactive activity4 ,a pulp or ketchup may be bad and show less than #cj1jjj1jjj bacteria1 or it may be good and show #cjj1jjj1jjj4 ,rotting1 or decomposition1 may depend more upon the cocci and the organisms which are not counted than upon those which are4 ,the only work done in which microscopical and chemical work were reported on the same samples appears in ,circular ,no4 #gh1 ,bureau of ,chemistry4 ,this was not done upon samples prepared and kept under control1 but for the most part upon commercial pulp and ketchup4 ,the results do not show any close relation between the number of organisms and the lactic acid content which is given as the measure of decomposition4 ,fourth4 ,bacteria are expressed in numbers per cc1 yeast and spores in numbers per #a-fj c mm4 ,since the counting can be done only in the fluid portion1 an error occurs proportional to the number of bacteria in or attached to the tissue which cannot be counted4 ,the error of assuming that numbers of organisms alone are a sufficient index of the wholesomeness of a food product is well illustrated by work on water analysis4 ,the following statement by an authority on the subject is illuminative3 8,the belief is widespread among the general public that the sanitary character of a water can be estimated pretty directly by the number of bacteria it contains4 ,taken by itself1 however1 it must be admitted that the number of colonies which develop when a given sample of water is plated affords no sure basis for judging its potability4 ,a pure spring water containing at the outset less than #ajj bacteria per cubic centimeter may come to contain tens of thousands per cubic centimeter within twenty-four to forty-eight hours1 after standing in a clean glass flask at a fairly low temperature4 ,there is no reason for supposing that the wholesomeness of the water has been impaired in any degree by this multiplication of bacteria40#c ----- ,footnote #c3 ,jordan1 ,e4 ,o4 ,a text-book of ,general ,bacteriology4 #aijh4 ,there are certain steps in the process of manufacture which also influence the number of organisms which may be counted4 ,a pulp may vary from an unevaporated tomato juice to a concentration which is represented by an evaporation of a volume of water up to #fj per cent1 and ketchup may vary from a thin watery consistency to one which is so heavy that it will scarcely flow from the bottle4 ,it becomes evident that a method which does not sustain some close relation to the amount of tomato present would naturally be deficient as a standard for judging4 ,for example1 a tomato juice with an initial count of #aj1jjj1jjj if evaporated to one-half its volume will have more than twice the number of organisms estimated in the original4 ,the pulp is composed of both liquid and solids and part of the liquid portion only is driven off by evaporation1 leaving in the residue a different proportion to the solids4 ,as the organisms can be counted only in the liquid portion1 it is obvious that with concentration1 the number will be increased at a much greater ratio than will the reduction of the bulk4 ,a thin pulp with #aj1jjj1jjj bacteria may easily be worse than a heavier one with #cj1jjj1jjj or #dj1jjj1jjj1 if judged by numbers alone4 ,the same conclusion is necessarily true for ketchup4 ,it clearly refutes the argument that a product having twice as many bacteria as another of the same kind is more than twice as bad4 ,the effect of recommending an arbitrary low limit for bacterial content1 irrespective of the consistency of the product1 is to cause manufacturers to pack thin pulp and sloppy ketchup1 and to discourage the more desirable heavy body4 ,the examination of a very large number of samples shows that the majority of the heavy pulps and ketchup upon the market show much higher counts than the thin ones when the tissues show good stock in both4 ,it is not possible to concentrate any pulp to the consistency of paste and have it pass under the present method2 that is1 considering a product to be filthy1 putrid or decomposed if the bacteria exceed #be1jjj1jjj per cubic centimeter4 ,there are some soup and ketchup manufacturers who still follow the draining method for separation and this is generally done to secure a certain quality in the flavor4 ,this kind of pulp always shows a high bacterial count1 which is usually ascribed to fermentation4 ,as the draining can be started in about twenty minutes1 and is nearly always completed in forty minutes to one hour1 there is little time for fermentation1 and yet such a pulp may show several times the count of the original whole pulp4 ,the condition is similar to that which takes place in the separation of cream by gravity4 ,dr4 ,john ,f4 ,anderson1 ,u4 ,s4 ,public ,health ,service1#d has shown that the bacterial content of gravity cream is about sixteen times that of bottom milk and that this discrepancy may be much wider4 ,one test is given in which the cream showed #chf times as many organisms as the bottom milk4 ,the question logically arises whether1 if a pulp which contains #aj1jjj1jjj bacteria per cubic centimeter and is considered sound1 becomes 8filthy1 putrid or decomposed0 when the same pulp is heavily concentrated and the count becomes #ajj1jjj1jjj1 or a cream is bad when it contains #b1jjj1jjj1 though the whole milk from which it was derived contained only #cjj1jjj4 ,there should be a recognized difference in rating a product in which the number of organisms is influenced by concentration1 and one in which they have developed4 ,some very erroneous statements have been made upon increase of bacteria in pulp while standing4 ,some of these have been based upon the academic proposition that reproduction in bacteria may occur every twenty minutes under perfect conditions of food supply1 freedom of movement1 and optimum temperature4 ,such statements are obviously not based on experiments with pulp4 ,assuming that such a rate of reproduction were possible1 a pulp with an initial start of only #e1jjj1jjj would increase to #aj1jjj1jjj in twenty minutes2 #bj1jjj1jjj in forty minutes2 #dj1jjj1jjj in one hour2 #hj1jjj1jjj in one hour and twenty minutes2 #afj1jjj1jjj in one hour and forty minutes2 #cbj1jjj1jjj in two hours2 and #b1efj1jjj1jjj in three hours4 ,no food product like tomato pulp1 cider1 or grape juice would be usable in a very short time4 ,to determine the rate of increase of the organisms in tomato pulp1 experiments were made1 using sound tomatoes4 ,in each experiment1 the tomatoes were divided into two lots1 one lot used raw1 the other steamed1 the steaming varying from two minutes' time1 just sufficient to slip the skins1 and eight minutes1 in which the whole tomato is softened4 ,samples were taken at hourly intervals for the first six hours1 then at intervals of twelve hours1 the samples counted by means of the plate and direct methods4 ,for the plates tomato gelatin was used with an acidity of #j4c and #j4d1 the samples for the direct count were put in cans1 sterilized1 and counted later4 ,with the lower acidity there were liquifiers which prevented the counting of some plates1 so that in the later trials the higher acidity gelatin was used4 ,the count of the molds was not normal1 due to the frequent stirrings1 which prevented spore formation1 besides injuring the hyphae4 ----- ,footnote #d3 ,the ,journal of ,infectious ,diseases4 #aiji4 ,vol4 #f1 p4 #cic4 ,the results varied1 some pulps giving a much higher initial count than others1 but they all agreed in having a comparatively slight increase in the first three hours1 the large numbers which one is led to expect not being present until the pulp had stood for at least five hours and under the most favorable conditions2 usually it requires a longer time4 ,the plates and the direct count agreeing in the general trend1 though the numbers obtained by the two methods varied4 ,in the pulp obtained from the steamed tomatoes1 the initial count was much lower in the tomatoes steamed eight minutes1 being only #bj per cc in the plates1 but the same thing was true of these in that the increase was very slow at first4 ,the figures from all the trials1 both raw and steamed pulp1 and from the plates and direct counts1 show that the theoretical estimation of the increase of organisms from the classic twenty minutes required for reproduction of an organism with the consequent progression1 irrespective of the condition of the organism at the start1 or its environment1 will have to be modified4 ,in the plates all colonies1 aside from the molds1 were counted as bacteria1 but this would not give a very large error1 as yeast does not reproduce at the same rate as do bacteria4 ,the state of comminution of the product determines to a considerable extent the number of organisms which may be counted4 ,the more finely the comminution1 the greater the number4 ,two pulps made from the same material1 one run through an ordinary cyclone and the other through a finishing machine1 will show from #ej to #ajj per cent more in the latter4 ,coarse pulp and coarse ketchup may be inferior articles and yet give the better results by the direct method4 ,the effect on the mold is even more marked--filaments and clumps will be torn into many small particles4 ,the total quantity is not increased1 but it is distributed more nearly perfectly and thus occurs in more fields4 ,in work done on meat to determine the technique which should be employed in the bacteriological analysis1 comparison was made between shaking the sample and grinding it in a mortar with sand4 ,in the three samples reported1 the shaking gave only #c1 #ab1 and #ac per cent1 respectively1 of those obtained from grinding4#e ----- ,footnote #e3 ,weinzirl1 ,john and ,newton1 ,e4 ,b4 ,american ,journal of ,public ,health4 ,vol4 ,,iv1 ,no4 #e4 ,a finely comminuted pulp was vigorously shaken for definite times and samples taken as quickly as possible after the tenth1 fiftieth1 one hundredth1 and two hundredth times shaken4 ,the results were as follows3 ,mold ,yeast and in ,per ,no4 ,times ,bacteria ,spores ,per ,cent of ,no4 ,shaken4 ,per c4c4 #a-fj c4c4 ,fields4 #a #aj #ca1jbj1jjj #bb #hj #b #ej #ej1jdj1jjj #db #gf #c #ajj #hd1gcj1jjj #ajf #ib #d #bjj #aaf1fdj1jjj #aaf #ajj ,in line with this are the results obtained before and after shipping long distances4 ,when the goods have been handled roughly during shipping the count is much higher4 ,the length of time elapsing after manufacture until the counting is done also has an effect4 ,pulp put up in the fall will show one count and the same pulp the following season a different count4 ,this difference is not due to any multiplication during storage1 but to the fact that the organisms separate from the tissues more readily4 ,the difference made in the counting from this treatment is not as marked as that produced by the other factors already treated1 but is sufficient to cause a change in the count4 ,it is known that the surface of plants is covered by a variety of bacteria and other fungi that remain dormant under unfavorable conditions1 but that these become active when the food which is invariably present is rendered available by access of moisture1 either dew or rain1 or the rupture of the host1 etc4 ,these will vary in numbers with the season1 wet or dry1 hot or cold1 in different sections of the country1 and1 in the case of the tomato1 with the variety of the fruit2 whether perfectly smooth or with a slight bloom2 whether irregular or regular in shape2 and whether slightly green with a firm skin or fully ripe4 ,these are all factors that have an influence and should not be overlooked4 ,some packers have already learned that by packing tomatoes which are colored1 but not really ripe1 that the count will be lower1 and as such a practice extends1 it means the use of poorer material instead of that which is properly developed and with the normal flavor4 ---------------------------------------- -------------------------------- ,transcriber's ,notes3 ,typographical errors were silently corrected4 ,inconsistent spelling and hyphenation were made consistent only when a predominant form was found in this book4 ,text in bold is enclosed by 8equal0 signs 7bold74