,issued ,january #i1 #aiji4 ,u4 ,s4 ,,department ,,of ,,agriculture1 ,,bureau ,,of ,,chemistry--,,bulletin ,no4 #aai4 ,h4 ,w4 ,,wiley1 ,chief of ,bureau4 ,,experiments ,,on ,,the ,,spoilage ,,of ,,tomato ,,ketchup4 ,,by ,a4 ,w4 ,,bitting1 ,,inspector1 ,,bureau ,,of ,,chemistry4 ,illustration3 ,shield of the ,united ,states ,department of ,agriculture ,,washington3 ,,government ,,printing ,,office4 #aiji4 ,,letter ,,of ,,transmittal4 ,u4 ,s4 ,department of ,agriculture1 ,bureau of ,chemistry1 ,washington1 ,d4 ,c41 ,july #ae1 #aijh4 ,sir3 ,i have the honor to submit for your approval a report made by ,inspector ,bitting of experimental work on the spoilage of tomato ketchup1 the conditions contributing thereto1 methods of prevention1 the action of preservatives1 and the length of time that the product will keep under varying conditions of manufacture and temperature1 both before and after opening4 ,every effort has been made to conduct the work in a practical way1 and the results obtained can not fail to be of interest and profit both to the manufacturer and consumer4 ,i recommend that this report be published as ,bulletin ,no4 #aai of the ,bureau of ,chemistry4 ,respectfully1 ,h4 ,w4 ,wiley1 ,chief4 ,hon4 ,james ,wilson1 ,secretary of ,agriculture4 ,,contents4 ,page4 ,introduction #g ,process of manufacture #h ,selection and preparation of stock #i ,pulping #i ,cooking and seasoning #aj ,evaporation and finishing #aa ,bottling #aa ,processing #aa ,character of products #ab ,first-class products #ab ,inferior products from 8trimming stock0 #ac ,labels #ad ,manufacturing experiments without the use of preservatives #ae ,outline of experiments #ae ,discussion of results #ag ,spoilage of ketchup after opening #ag ,spoilage of unopened ketchup #bj ,spoilage of market brands #bj ,sterility of ketchup #ba ,experiments with preservatives #bb ,sodium benzoate #bb ,salt #bc ,sugar #bc ,spices #bd ,water infusions #bd ,acetic acid extracts #be ,oil extracts #be ,vinegar and acetic acid #bf ,oil #bg ,study of ,penicillium in ketchup #bh ,development #bi ,reproduction #bi ,growth in ketchup #cj ,temperature tests #ca ,histological structure of ketchup #cc ,microscopical examination of some commercial brands #cd ,summary #ce ,,illustrations4 ,,plates4 ,page4 ,,plate ,i4 ,penicillium4 ,fig4 #a4--;,conidia1 normal growth and in various stages of germination1 some with branching hyph4 ,fig4 #b4--;,conidiophore1 showing unusually large development of conidia2 from culture in moist chamber #bh ,,ii4 ,cultures from ketchup preserved with sodium benzoate4 ,fig4 #a4--;,conidia and hyph from culture in experimental ketchup containing one-sixteenth of #a per cent of sodium benzoate4 ,fig4 #b4--;,conidia and hyph from culture in experimental ketchup containing one-tenth of #a per cent of sodium benzoate #bh ,,text ,,figures4 ,fig4 #a4 ,a model receiving platform #h #b4 ,large receiving room showing the sorting belt #i #c4 ,a section of a kitchen showing the copper cookers #aj #d4 ,an example of factory practice #ab #e4 ,another factory interior #ad ,,experiments ,,on ,,the ,,spoilage ,,of ,,tomato ,,ketchup4 ,,introduction4 ,the tomato1 ,lycopersicum esculentum1 is supposed to be native to ,south or ,central ,america4 ,the large fruits commonly used grow only under cultivation1 but the variety with small1 spherical fruits1 known as ,l4 cerasiforme1 has been found on the shore of ,peru and is considered by ,de ,candolle,a as belonging to the same species as ,l4 esculentum4 ,though grown extensively in ,europe1 there is nothing to indicate that it was known there before the discovery of ,america4 ,the tomato was introduced into ,china and ,japan at a comparatively recent date4 ,de ,candolle is of the opinion that the tomato was taken to ,europe by the ,spaniards from ,peru and was later introduced into the ,united ,states by ,europeans4 ,tomatoes were brought to ,salem1 ,mass41 by an ,italian painter in #ahjb1;,b who is said to have had difficulty in convincing the people that they were edible4 ,they were used in ,new ,orleans in #ahab1 though as late as #ahce they were sold by the dozen in ,boston4 ,after #ahdj they came into general use in the ,eastern ,states1 but it was later than this before tomatoes were used freely in the ,western ,states1 many persons having the impression that1 since they belonged to the nightshade family1 they must be unwholesome4 ,the extent to which tomatoes are used at the present time shows how completely this prejudice has been overcome4 ,a ,origin of ,cultivated ,plants1 #ahij4 ,b ,webber1 ,h4 ,j41 ,yearbook1 ,u4 ,s4 ,department of ,agriculture1 #ahii4 ,the name ,lycopersicum is from two ,greek words1 meaning a wolf1 and a peach1 the application of these terms not being apparent2 the name of the species1 esculentum1 is from the ,latin1 meaning eatable4 ,the common name 8tomato0 is of ,south or ,central ,american origin1 and is believed to be the term used in an ancient ,american dialect to designate the plant1,c but its meaning is unknown4 ,the ,english call the tomato 8love apple10 which in ,french is 8pomme d'amour40 ,c ,u4 ,s4 ,dept4 ,agr41 ,exper4 ,sta4 ,record1 #ahii-aijj1 #aa3 #bej4 ,the tomato is considered a typical berry1 the ovary wall1 free from the calyx1 forming the fleshy pericarp1 which incloses chambers filled with a clear matrix containing the seeds4 ,the fruit measures from #a to #e inches in diameter1 and is red1 pink1 or yellow when mature4 ,the plant sports freely1 producing many varieties1 which differ mainly in the size1 shape1 and quality of the fruit4 ,the varieties bearing small fruits are ,l4 cerasiforme and ,l4 pyriforme1 each bearing a two-celled fruit1 the former being round1 and somewhat larger than a cherry1 and the latter pear-shaped4 ,these small tomatoes are used ordinarily for preserves and pickles4 ,the word 8ketchup0 is adopted in this bulletin as the form which ought to be given preference4 ,the derivation of the term is not definitely known4 ,the spelling 8catchup0 given in some of the leading dictionaries appears to be based on the erroneous idea that the first syllable 8ketch0 is a colloquial form of 8catch40 ,several authorities derive the word from the ,east ,indian or ,malayan 8kitjap10 because 8ketchup0 was originally a kind of ,east ,indian pickles4 ,some give the word a ,chinese origin1 while others assert that it comes from the ,japanese4 ,a majority of the manufacturers employ the word 8catsup10 a spelling for which there does not appear to be any warrant4 ,,process ,,of ,,manufacture4 ,illustration3 ,fig4 #a4--;,a model receiving platform4 ,the making of tomato ketchup consists essentially in reducing tomatoes to pulp1 removing the skins1 seeds1 hard parts1 and stems1 adding salt1 sugar1 condiments1 and vinegar to suit the taste1 and cooking to a proper consistency4 ,the methods and practices of the various manufacturers differ1 and the difference between the best and the poorest procedure corresponds to that between the best and the worst ketchup4 ,no single factory has all of the best methods at every step of manufacture4 ,some perform certain details well and are negligent in others4 ,in some1 large amounts of money are spent on equipment to improve a particular point considered advantageous by the trade1 while other details essential to the making of a good-keeping ketchup are disregarded4 ,a statement of the best practice as observed at a number of factories1 together with some facts obtained from experiments1 will be given4 ,,selection ,,and ,,preparation ,,of ,,stock4 ,the tomatoes should be home-grown1 of a red variety having the minimum of yellow and purple color1 be picked when ripe1 and delivered to the factory promptly without mashing4 ,all tomatoes should pass over an inspection table1 the rotten and otherwise unfit fruit should be discarded1 and the green tomatoes should be returned to crates to ripen4 ,the stems should be removed when the best color is desired1 and the tomatoes should be thoroughly washed to remove dirt and mold4 ,dumping a crate of tomatoes into a hopper of dirty water and playing a gentle spray of water on part of them merely wets the skin and makes them appear bright4 ,illustration3 ,fig4 #b4--,large receiving room showing the sorting belt4 ,,pulping4 ,the clean tomatoes should be conveyed to the steaming tanks and subjected to steam heat until the skins burst and the meat softens4 ,after a short heating the tomatoes should be run through a 8cyclone0 where the skins1 seeds1 etc41 are removed and they are rubbed to a pulp4 ,to remove very small particles and fiber1 the pulp may be run through a sieving machine at once2 or1 if ketchup of the smoothest possible kind is to be made1 this procedure should be delayed until after the cooking4 ,the pulp is collected in a receiving vat1 and only such an amount should be provided in advance as will keep the kettles full1 as it is better to stop the tomatoes before going to the washer than to have the pulp stand for some hours4 ,in common practice1 however1 the pulp is either sent to the cooker at once1 or it is allowed to stand and partially separate4 ,if tall casks are used for this separation the solids will rise to the top and the clear watery portion is drawn off at the bottom1 or the pulp may be strained through cloth bags4 ,the object of this separation is to secure greater concentration of the solids1 retain a brighter color1 and shorten the time of cooking4 ,,cooking ,,and ,,seasoning4 ,illustration3 ,fig4 #c4--;,a section of a kitchen showing the copper cookers4 ,the cooking may be done in copper kettles1 as shown in figure #c1 though these are being superseded by enamel tanks containing silver-plated coils in order to secure the brightest color4 ,by using the latter the discoloration due to the splashing of the contents against the walls of the copper vessel is avoided1 and economy of space is secured4 ,whole or ground spices1 or acetic acid or oil extracts of the spices may be added to the pulp in such proportion as the particular brand demands4 ,the spices most used are cloves1 cinnamon1 mace1 and cayenne pepper2 but paprika1 pepper1 mustard1 cardamon1 coriander1 ginger1 celery1 and allspice are used by some manufacturers4 ,when whole spices are used1 it is the practice to suspend them in a cloth bag or a wire basket and to take them out after boiling4 ,they tend to darken the color of the ketchup1 a result considered undesirable by some4 ,the ground spices are used sparingly1 with the exception of cayenne pepper4 ,the acetic acid extracts of spices are used because they are economical and give a brighter red color than is obtained with the whole spice4 ,the oil extracts produce no discoloration1 but they are the most expensive and give an objectionable flavor4 ,hungarian sweet paprika is now quite largely used and adds to the color as well as to the flavor4 ,sugar1 salt1 and vinegar are added in such proportion as may be desired1 and in some brands onions and garlic are used4 ,,evaporation ,,and ,,finishing4 ,the pulp is evaporated rapidly to such consistency as the grade and price will warrant1 the reduction in volume being from #dj to #fj per cent4 ,this is accomplished in about forty-five minutes4 ,the cooking is not continued longer than is necessary1 as each minute added to the cooking darkens the finished product4 ,if the pulp has been run through the sieving machine before cooking1 the batch may be drawn off into the receiving tank for bottling4 ,if the finishing be done after cooking1 the pulp is run into a receiving vat1 finished as quickly as possible1 and drawn into the tank for bottling4 ,the ketchup may be kept at a high temperature--#bjj to #bjf ,f4--in the receiving tank by means of a small steam coil1 or it may be drawn to the bottling machine through a steam-jacketed tube4 ,finishing after cooking yields a slightly smoother ketchup than sieving before cooking2 but it necessitates handling1 reduces the temperature1 and increases the chances of infection4 ,,bottling4 ,the bottles should be thoroughly cleaned as ketchup will not keep if placed in bottles which have been merely rinsed to remove the straw2 if the ketchup is not to be given an after process the containers should be sterilized4 ,in the experimental work cork stoppers gave the best results and these should be sterilized in a paraffin bath at #bej ,f4 ,,processing4 ,an after treatment or process is given to bottled goods either in a water or steam bath1 the important point being that the center of the bottle be raised to the desired degree of heat4 ,if the ketchup is thin this can be effected quickly1 but if it is thick and heavy the heat penetrates the ketchup with surprising slowness4 ,in a thin ketchup the temperature may be raised from #adj to #aij ,f4 in eighteen minutes or less when the surrounding heat is #aie ,f2 but in a heavy ketchup it may take an hour or more to accomplish the same result4 ,it is therefore very important that the ketchup be processed immediately after it is corked1 before it has time to cool4 ,the rate at which the heating is effected for different goods can be determined by sealing a thermometer in the cork and recording the readings4 ,illustration3 ,fig4 #d4--;,an example of factory practice showing the top row of tanks from which pulp passes by gravity into the cookers1 then into the receiver1 sieving machine1 and final tub ready for the bottling machine or jug filler4 ,,character ,,of ,,products4 ,,first-,,class ,,products4 ,the factory at which the experiments were conducted has sanitary buildings and surroundings1 the floors are of concrete for flushing1 and the pipes used in conducting the pulp to the kitchens are porcelain-lined to prevent discoloration from the iron and to insure cleanliness4 ,the tubes which carry the ketchup from the kettles to the receiving tank1 finishing machine1 and bottler are silver-plated4 ,not all of these measures are necessary to make a good ketchup1 but they show the care exercised in making an article of good appearance and of the finest quality4 ,the conditions under which ketchup is made and the care with which the work is done at some of the better factories is equal to that used in the manufacture of any food product4 ,whole selected fruit is used1 cleanliness is maintained at every point1 the best grades of spices1 vinegar1 granulated sugar1 and salt are added for flavoring1 and the bottles are carefully washed4 ,the ketchup put up under such conditions will have a bright natural color1 will remain good as long as the container is unbroken1 and will continue in that condition for some time after opening if kept at a fairly cool temperature4 ,,inferior ,,products ,,from 8,,trimming ,,stock40 ,in contrast with the strictly high-grade product is the great bulk of the ketchup found on the market4 ,the material is not whole ripe tomatoes1 but consists of the waste of the canning factory1 commonly designated as 8trimming stock10 including the green1 moldy1 broken1 rotten1 and generally unusable tomatoes1 the skins1 cores1 and stems from the peeling tables1 and the surplus juice from the filling machines1 all of which may be allowed to stand during the day and be run through the cyclone in the evening4 ,at the end of the season1 the frosted and half-ripe fruits may be used4 ,part of this material can not be considered 8sound fruit0 as contemplated by the food and drugs act4 ,the pulp is put up in barrels1 preserved1 and allowed to stand1 possibly in the sun1 until a sufficient quantity has accumulated for shipment4 ,old ketchup barrels may be used and be none too clean4 ,as a result1 it is not uncommon to see an inch or more of pulp in the bottom of a car at the end of shipment1 caused by the blowing out of the barrel heads from fermentation4 ,the sanitary condition of the factory may be poor1 the handling of the goods be unclean1 the spices be the refuse from the spice houses1 the sugar be of the cheapest grade1 and the bottles be only rinsed or be used without even that precaution4 ,the ketchup is a concoction so heavily spiced with hot spices that the tomato flavor is lost and might as well be anything else4 ,the color is normally dirty brown4 ,between these two extremes are all grades1 those for which whole tomatoes1 unsorted1 are used1 those for which trimming stock is worked up promptly during the canning season1 and those made from stock of unknown history4 ,some manufacturers work under good and some under poor sanitary conditions4 ,there can be no doubt that with proper selection and precaution much of the by-product of the canning factory and large quantities of tomatoes which are unsuitable for canning might be used to advantage in the manufacture of ketchup2 but it requires a nicety of practice not generally found at this time4 ,the practice sometimes followed of making some ketchup from whole stock and a large quantity from refuse and using the former for advertising purposes1 only serves to emphasize the fact that the goods belong to two distinct classes4 ,one of the uses for a very considerable amount of pulp from refuse stock is the making of sauce for baked beans and other canned goods where the true character can not be observed by the consumer4 ,illustration3 ,fig4 #e4--;,another factory interior1 showing large pulp tanks in the rear1 cooking tanks on the right1 and process tanks in front containing thousands of bottles of ketchup4 ,during the season tomatoes come in at times in larger quantities than can be made into ketchup promptly4 ,the surplus must be worked up into pulp for storage and may be stored in barrels or in tin cans4 ,the pulp stored in barrels will not have as good a color as that put into cans1 and the ketchup made from either will not be as bright as that made from whole1 fresh stock4 ,the pulp put up in barrels is more liable to spoilage than that put up in cans4 ,the difference in the cost of storage by the two methods is not very great1 and some large concerns are using the can exclusively instead of the barrel4 ,,labels4 ,the labels on the ketchup bottles have been improved somewhat in the last year as regards exactness in describing the contents4 ,formerly1 according to the labels1 much of the ketchup was made from whole ripe tomatoes4 ,the question was1 ,what became of the enormous amount of ketchup which it was known had been made from 8trimmings80 ,on this year's ketchup the labels make fewer claims1 generally merely stating that it is 8tomato ketchup10 which is true whether made from whole tomatoes or refuse4 ,the brand is in most cases the guaranty for good quality4 ,it is not safe to judge the quality by the price1 for1 though usually good quality can not be expected unless the higher price is paid1 some of the high-priced ketchup when placed under the microscope has proven to be a very inferior product4 ,the wide labels on the neck of the bottle are objectionable4 ,some of these are #b inches in height1 and serve to cover the discolored and spoiled ketchup4 ,as spoilage begins usually in the neck of the bottle1 it is difficult to see it when the neck is wrapped with a label1 and thus it might easily be overlooked until the main body of the ketchup is affected4 ,the bottles which have the widest labels around the neck are usually the ones provided with one or two large labels on the lower part of the bottle1 though some bottles have no other label but the one around the neck4 ,as a rule1 however1 these are narrow1 close to the stopper1 and unobjectionable4 ,in buying ketchup for experimental purposes it was difficult and sometimes impossible to learn its age1 as often the grocer does not know it1 and at other times he will not tell4 ,it appeared1 however1 that often the ketchup had been on the grocer's shelf or in the warehouse from one to four years4 ,,manufacturing ,,experiments ,,without ,,the ,,use ,,of ,,preservatives4 ,,outline ,,of ,,the ,,experiments4 ,during ,september1 #aijg1 ketchup was made in experimental batches to determine whether it could be manufactured on a commercial scale without the use of preservatives4 ,these experiments were made to determine 7#a7 the keeping quality before opening the container and 7#b7 the length of time the product will keep without spoilage after the bottle is opened4 ,the ketchup was made in a factory in which the conditions of manufacture and all the surroundings were sanitary2 whole1 ripe tomatoes1 the same as used in the regular grade of canned goods1 were used and the formula and process were for a mild ketchup giving the maximum of tomato flavor4 ,each batch consisted of #ej gallons of finished goods1 from which #a gross of pint bottles was retained for observation4 ,the term 8regular ketchup0 as used in these experiments means the pulp of fully ripe tomatoes1 to which was added granulated sugar1 #hj-;grain1 distilled vinegar1 table salt1 onions1 garlic1 whole cinnamon1 cloves1 mace1 and ground cayenne pepper4 ,the pulp was cooked in a steam-jacketed copper kettle for forty minutes and reduced about #ej per cent4 ,the finishing was done after cooking4 ,the regular bottles are pint sizes1 washed in hot water1 rinsed1 and then heated to a temperature of #aij ,f4 for thirty minutes or more4 ,the sterile bottles referred to in the experiments were placed in a steam chamber for twenty minutes at #bcj ,f4 ,the corks were sterilized by a bath in paraffin at about #bgj ,f4 ,all of the work was accomplished quickly to insure a smooth1 even product with a bright1 clean color4 ,acetic acid extracts and oil extracts of spices were used in such quantities as would give the same amount of spicing as when the whole spices were employed4 ,in all of the following experiments the ketchups discussed were made in ,september1 #aijg1 and the last examination reported was made ten months later1 in ,july1 #aijh3 ,experiment ,no4 #a4--,regular ketchup was made1 but it was reheated after finishing and bottled in sterile bottles at a temperature of #bje ,f4 ,no spoilage has occurred at the end of ten months4 ,experiment ,no4 #b4--,regular ketchup was made1 and it was bottled immediately after finishing in regular bottles at a temperature of #afe ,f4 ,an after process was given at #aij ,f4 for twenty minutes4 ,no spoilage has occurred after ten months4 ,experiment ,no4 #c4--,regular ketchup was made1 and was bottled in regular bottles at #afe ,f41 and given a subsequent process at #aij ,f4 for forty minutes4 ,no spoilage has occurred4 ,experiment ,no4 #d4--,regular ketchup was made1 was bottled in regular bottles at a temperature of #afe ,f41 and given an after process at #bab ,f4 for twenty minutes4 ,no spoilage has occurred4 ,experiment ,no4 #e4--,regular ketchup was made1 the same being put up in regular bottles at a temperature of #afe ,f4 and given an after process at #bab ,f4 for forty minutes4 ,no spoilage has occurred4 ,experiment ,no4 #f4--,ketchup was made in which the acetic acid extracts took the place of whole spices1 and the bottling was done at a temperature of #afe ,f41 no after treatment being given4 ,no spoilage has occurred4 ,experiment ,no4 #g4--,ketchup was made in which acetic acid extracts were used1 and the bottling was done at a temperature of #afe ,f4 in sterile bottles4 ,no after treatment was given and no spoilage has occurred4 ,experiment ,no4 #h4--,ketchup was made in which the oil extracts were used instead of regular spices4 ,the bottling was done in regular bottles at a temperature of #afe ,f41 no after treatment being given4 ,no spoilage has occurred4 ,experiment ,no4 #i4--,ketchup was made in which oil extracts were used instead of whole spices4 ,the bottling was done at #afe ,f4 in sterile bottles1 no after treatment being given4 ,no spoilage has occurred4 ,experiment ,no4 #aj4--,regular ketchup was made1 but the pulp was run through the sieving or finishing machine before instead of after cooking1 the object being to determine the effect upon the character of the goods rather than upon the spoilage4 ,this practice could be followed to advantage in making all except the very finest goods1 and would give the same condition for bottling as in experiment ,no4 #a4 ,experiment ,no4 #aa4--,pulp was made in the usual manner and run into barrels while just below the boiling point4 ,the barrels had been thoroughly washed and then steamed for twenty minutes4 ,as soon as the pulp had cooled slightly the bung was driven in tightly and the barrel was rolled into storage4 ,at the end of sixty days the barrels were opened and the pulp was found to be in good condition4 ,experiment ,no4 #ab4--,regular ketchup was drawn into #e-;gallon jugs which had been sterilized in the same manner as the bottles4 ,these were kept for sixty days and no spoilage occurred4 ,,discussion ,,of ,,results4 ,twelve hundred and ninety-six bottles were shipped from ,terre ,haute to ,lafayette1 ,ind41 and some were reshipped in order to duplicate the conditions in trade4 ,some were kept in a warm temperature and in strong light1 others in a comparatively cool place and in the original shipping cases1 in order to duplicate the conditions in the warehouse and grocery store4 ,there has been no spoilage after ten months other than that resulting from four or five cork leaks and neck cracks4 ,these experiments have shown conclusively that ketchup can be put up on a commercial scale and delivered to the consumer in perfect condition without the use of a preservative4 ,it was demonstrated by the first experiment that the goods could be bottled at a high temperature without difficulty1 and that subsequent treatment was unnecessary4 ,the after treatment at #aij was tried because it had been found in small experiments that1 in giving a higher temperature1 the internal pressure would cause more or less breakage of bottles or loosening of corks4 ,after treatment is practiced by some who also use a small quantity of preservative as a further precaution4 ,this treatment is continued from two to three hours at the temperature of high pasteurization4 ,the process at #bab was given with little breakage1 as the bottles used were of good quality4 ,at and above this temperature the breakage may be reduced by either raising the temperature of the ketchup before bottling or applying pressure upon the outside while giving the process4 ,neither the acetic acid nor the oil extracts showed any advantage over whole spices in their preservative effects1 as all kept4 ,the color was slightly improved1 but the flavor was impaired1 particularly when the oil extracts were used4 ,,spoilage ,,of ,,ketchup ,,after ,,opening4 ,the question of how long the ketchup should keep after opening the container in order to satisfy the ordinary requirements of consumption was also studied4 ,a local restaurant1 serving about two hundred meals and using from one-half to a gallon of ketchup daily1 was supplied with the same kind of ketchup used in the experiments1 as were also some families4 ,instructions were given to use the ketchup as they would ordinarily1 with the result that none reported any loss from spoilage4 ,to determine how long the ketchup would keep after opening1 #h bottles from each of the first #i experiments were kept in the kitchen at a temperature of about #gb ,f41 #e were kept in an incubator at a temperature of #ie ,f41 #e were kept in the laboratory at a temperature of about #fg ,f41 and #d were kept in an inclosed porch where the temperature ranged from #cj to #fj ,f4 ,this made a total of #aih bottles4 ,no precautions1 other than those of ordinary cleanliness1 were taken in opening the bottles1 as it was desired to determine the keeping properties under conditions of general usage4 ,the first set of bottles was opened ,november #e1 immediately on being received at the laboratory1 all of the ketchup having been kept at the factory until the experiment begun in ,september was completed4 ,the bottles were covered loosely with a metal cap and observed daily1 a record being kept of the date and character of spoilage4 ,the results showed that the differences in the time and temperature of processing had little1 if any1 effect in checking the spoilage2 neither did the use of acetic acid or oil extracts4 ,the most important precaution in checking the spoilage after opening seems to be to keep the ketchup cool4 ,this is shown by the average number of days which elapsed before spoilage occurred in the sets kept under different temperature conditions4 ,for those kept in the kitchen the average number of days was six1 the minimum three1 and the maximum eleven4 ,those in the incubator kept for an average of five days1 with a minimum of two days1 and a maximum of eight4 ,those in the laboratory had an average of eight days1 the minimum being four days and the maximum twenty-two4 ,those kept in the porch lasted on an average twenty-seven days1 a minimum of twelve days1 and a maximum of fifty-eight4 ,these figures show the definite relation of temperature to spoilage under the conditions of ordinary use4 ,in making the observations1 the metal cap was removed each day1 but no ketchup was poured off4 ,the spoilage in all cases was due to mold1 and usually this formed in the neck of the bottle where the ketchup had splashed1 or at the junction of the ketchup with the bottle4 ,the spoilage was recorded as soon as the slightest growth appeared4 ,in actual use if the neck were wiped out when the ketchup had been used and a growth of mold removed on its first appearance with some of the proximate ketchup the time before spoilage occurred could be prolonged4 ,in these experiments the attempt was made to determine how soon growth appeared under the various conditions of temperature named4 ,the unopened bottles of ketchup were kept in a basement room1 the temperature of which is fairly constant1 being about #gj ,f4 ,this is approximately the condition in a grocery where the ketchup is kept on the shelves4 ,another set of samples from the run of ,september1 #aijg1 was opened ,february #aa1 #aijh1 to determine if storing in a warm room before opening had any effect on the length of time preceding spoilage4 ,four bottles were taken from each of the first #i experiments to make up each of three sets1 one of which was kept in the kitchen1 one in the incubator1 and one in the porch1 making a total of #ajh bottles4 ,the average number of days for those kept in the incubator was four1 the minimum two1 and the maximum six4 ,the average number of days before spoilage in the kitchen was five1 the minimum being three and the maximum nine4 ,those kept in the porch gave an average of twenty-three days1 the minimum number being eighteen days and the maximum seventy-three days4 ,thus it is seen that the ketchup lasted nearly five times as long at a temperature of #cj to #fj ,f4 as it did at #gb2 and also that when ketchup is kept in a warm place before opening1 spoilage occurs somewhat sooner1 the average for the fresh samples opened under the same conditions being one day more with the incubator and kitchen samples and four days more with the porch samples4 ,a third set of bottles of the ketchup was opened on ,june #f1 #aijh1 or two hundred and sixty-five days after manufacture4 ,they had been kept in a basement at a temperature of about #gj ,f4 ,one set was placed in the incubator at a temperature of #ie ,f41 one set in the kitchen at about #hb ,f41 and one set in the refrigerator at #df ,f4 ,the weather was warm and the conditions favorable to the spoilage of fresh foods4 ,the minimum time for spoilage in the incubator was two days1 the maximum time four days1 and the average time three and two-tenths days4 ,the minimum time in the kitchen was two days1 the maximum time six days1 and the average time four and four-tenths days4 ,the minimum time in the refrigerator was nine days1 the maximum time nineteen days1 and the average time thirteen and sixty-six one-hundredths days4 ,these data are grouped in the following table for easier comparison3 ,time of spoilage of ketchup at different temperatures after opening4 ,,opened ,,on ,,november #e1 #aijg1 ,,immediately ,,upon ,,receipt ,,from ,,factory2 ,,maximum ,,age1 ,,five ,,weeks4 ---------------------------------------- ------------------------- ,place of storage4 ,temperature4 ,lapse of time before spoilage4 ------------------------------- ,average4 ,minimum4 ,maximum4 ------------------ ----------------------------- ,f4 ,days4 ,days4 ,days4 ,incubator #ie #e #b #h ,kitchen #gb #f #c #aa ,laboratory #fg #h #d #bb ,porch #cj-fj #bg #ab #eh ---------------------------------------- ------------------------- ,,kept ,,at #gj ,f4 ,,for ,,one ,,hundred ,,and ,,fifty ,,days ,,before ,,opening ,,on ,,february #aa4 ---------------------------------------- ------------------------- ,incubator #ie #d #b #f ,kitchen #gb #e #c #i ,porch #cj-fj #bc #ah #gc ---------------------------------------- ------------------------- ,,kept ,,at #gj ,f4 ,,for ,,two ,,hundred ,,and ,,sixty-,,five ,,days ,,before ,,opening ,,on ,,june #f4 ---------------------------------------- ------------------------- ,incubator #ie #c4b #b #d ,kitchen #hb #d4d #b #f ,refrigerator #df #ac4ff #i #ai ---------------------------------------- ------------------------- ,,spoilage ,,of ,,unopened ,,ketchup4 ,another test was made to determine whether the ketchup would spoil when kept in a warm place1 but not opened4 ,three bottles from each experimental batch were placed in the incubator ,november #g1 #aijg1 and were kept there until ,december #bc1 #aijg--;forty-six days--and in that time there was no sign of spoilage4 ,they were then opened and kept in the laboratory2 the average number of days before spoilage occurred is indicated in the following table3 ,average number of days before spoilage of ketchup after opening 7kept #df days at #ie before opening74 --------------------------------------- ,experiment ,no4 ,days before spoilage4 -------------------------------------- #a #b #b #d #c #c #d #e #e #e #f #d #g #d #h #d #i #c --------------------------------------- ,it will be observed that these samples spoiled in about the same length of time as the bottles opened in ,february and tested in the incubator1 so that similar results were obtained by keeping unopened ketchup one and one-half months at #ie ,f4 and keeping it five months at #gj ,f4 ,from the results of the experiments it is evident that the ingredients of the ketchup in the proportions used are not antiseptic1 and it is also apparent from the number of organisms found and the rapidity of their multiplication that ketchup is a good1 nutritive medium4 ,yeasts and molds are the predominating organisms1 and1 as the ketchup is acid and also contains sugar1 and these organisms are found on tomatoes in the field1 their predominance in the ketchup is explained4 ,,spoilage ,,of ,,market ,,brands4 ,to determine the keeping properties of the ketchup on the market1 various brands were obtained from the grocery stores4 ,in the majority of cases nothing was known of the ingredients or methods of manufacture1 except what appeared on the labels4 ,no date of manufacture was given1 and in some cases the dealers did not know the age of the product4 ,there were #ajd bottles of ketchup opened to find out how long they would remain in good condition4 ,these were kept in the laboratory1 though the temperature was higher than that at which ketchup should be held4 ,of the #ajd bottles there were #ff without preservative1 according to the labels1 #df of which spoiled4 ,of the #bj which did not spoil1 #b formed crystals of benzoic acid on the covers of glass dishes during evaporation4 ,of the #ci which1 according to the labels1 contained sodium benzoate1 #ae spoiled4 ,the bottles of unspoiled ketchup after remaining in the laboratory for about a month were placed in the incubator at #ie ,f4 for three weeks1 and were then taken out1 and have been left in the laboratory since4 ,the metal cap had been taken off frequently for observation1 and the ketchup exposed1 but the treatment did not cause them to spoil4 ,the average number of days after which spoilage occurred for the #df bottles without preservative was about fifteen1 the minimum number being four days1 the maximum number ninety-four days4 ,the average number of days preceding spoilage in the case of #ae bottles with preservative was twenty-four days1 the minimum number being three and the maximum sixty days4 ,the majority of these had #j4a per cent of sodium benzoate present2 the others had a smaller amount1 according to the manufacturer's label4 ,these data are not at all conclusive and further work on material of known history will be necessary4 ,,sterility ,,of ,,ketchup4 ,to determine the sterility of ketchup1 cultures were made from #gg of the bottles4 ,the method used was to wipe the bottles and cork stoppers with a damp towel and then remove the cork4 ,the cork puller which was used grasps the neck of the bottle in such a way as to cover the opening and remove the cork without the inrush of air that occurs when the ordinary corkscrew is used4 ,a flame was then passed over the mouth of the bottle1 after which the upper layer of ketchup was poured out1 so as to discard any material which might have been contaminated in handling4 ,tomato gelatin was used as a medium and cultures were made in petri dishes4 ,there were #ag plates on which no organisms developed1 indicating that the ketchup was sterile4 ,of the #fj plates having organisms1 #ed had molds1 #bb of these having molds alone2 #ba plates had yeast-like organisms1 #c plates having these only2 #bi plates had bacteria1 #d having bacteria alone4 ,sometimes a plate would have only one form of organism1 but more often there was a mixture present4 ,of #ae plates having only one form of organism1 #c had yeast alone1 #b bacteria alone1 and #aj had mold alone4 ,of the #gg bottles of ketchup from which the inoculations were made1 #da were without and #cf with preservative1 and of the #ag sterile ketchups1 #h contained sodium benzoate and #i were without preservative4 ,a considerable part of the experimental ketchup proved not to be sterile4 ,the organisms present were of the class which require oxygen for their growth and therefore they had only been arrested in their activity4 ,no growth could take place so long as the air was excluded and therefore no spoilage could occur4 ,when the cork was drawn1 the organisms could grow and cause spoilage1 and this is a much more potent factor than the entrance of germs from without4 ,bottling and sealing the ketchup quickly while hot so completely excludes the air that only a few colonies of yeast or mold may be found on subsequent microscopical examination4 ,filling at a low temperature and corking while cool allows sufficient air to remain incorporated in the ketchup and neck of the bottle to permit a considerable growth of the organisms and a product derived from good stock may thus acquire the appearance of ketchup derived from partially decayed material4 ,a ketchup in which bubbles of air are incorporated in filling may show a growth of mold at each bubble throughout the mass4 ,the foregoing statements apply to ketchup containing sodium benzoate as well as to the non-preservative goods of the character used in these experiments4 ,,experiments ,,with ,,preservatives4 ,,sodium ,,benzoate4 ,the preservative in general use in ketchup is sodium benzoate4 ,salicylic acid is used1 but only to a limited extent4 ,the amount of sodium benzoate used1 according to the labels1 varies from one-sixteenth to one-tenth of #a per cent2 but on some labels the amount is not stated4 ,experiments were made to determine the amount necessary to check the spoilage of ketchup4 ,two organisms1 a mold and a yeast1 were selected on which to make the tests4 ,the mold was the ordinary blue mold1 ,penicillium1 which was present in many of the brands of ketchup and is found commonly on acid foods4 ,it was selected on account of its prevalence and resistive power4 ,the yeast was obtained from ketchup and was also a vigorous grower1 forming a thick1 wrinkled film on various media4 ,any effect on the growth of the yeast could be seen readily in its manner of forming the film4 ,portions of tomato gelatin to which #j4a1 #j4e1 #a1 and #b per cent1 respectively1 of sodium benzoate were added1 were first inoculated with the mold4 ,there was no development in those containing #a and #b per cent2 a retarded development resulted in that containing #j4e per cent1 and the growth when #j4a per cent was used was nearly normal1 showing very little difference from that in the gelatin without sodium benzoate4 ,ketchup was next tried as a medium1 but the amount of benzoate was reduced to one-sixteenth1 one-twelfth1 and one-tenth of #a per cent1 as it was thought that some of the other constituents of the ketchup were antiseptic to a slight degree4 ,the growth in the ketchup was irregular1 though the benzoate checked development in all4 ,equal amounts of benzoate were used in tomato bouillon1 with practically the same results as in the ketchup4 ,the development was checked in all1 and in some plates one-sixteenth of #a per cent seemed to be fully as efficacious as one-tenth of #a per cent4 ,when the mold was examined under the microscope1 the filaments were found to be much swollen and distorted in shape1 and filled with a coarsely granular protoplasm1 containing much fat1 as indicated by the blackening with osmic acid4 ,the culture containing the mold which gave the least development seemed to show the least distortion and swelling of the filaments4 ,the results indicated that in using sodium benzoate as a preservative there is uncertainty as to results1 even when using the maximum amount allowed--one-tenth of #a per cent4 ,they also indicated that this preservative had an injurious effect on the living matter of the mold4 7,see ,pl4 ,,ii2 compare with normal growth1 ,pl4 ,i47 ,,salt4 ,the effect of salt in checking development was tested by using tomato bouillon as a medium and adding #e1 #aj1 #ae1 #bj1 #be1 and #cj grams of salt1 respectively1 to #ajj cc4 ,these were inoculated with the mold4 ,the #e-;gram solution seemed to have no effect on development4 ,when #aj grams were used growth appeared as soon as in the bouillon without salt1 but was not so extensive4 ,in the #ae-;gram solution growth was retarded four days1 and most of that which did develop remained submerged1 the mold growing normally on the surface4 ,with #bj grams the growth was five days slower than the normal in starting1 and after that there was only a slight development4 ,in the #be-;gram solution1 the growth started at the same time as when #bj grams were employed1 but remained stationary1 while with the #cj-;gram solution1 no development occurred4 ,the yeast was checked slightly by #e grams1 and very materially by the #aj-;gram solution1 as it required two days for a thin1 delicate film to form1 whereas in ordinary solutions a rather thick film is formed within twenty-four hours or even in less time4 ,there was no development in the #ae-;gram solution4 ,,sugar4 ,the effect of sugar was tested on both the mold and the yeast by adding it to tomato bouillon4 ,it was supposed that a low percentage of sugar like the salt would plasmolyze the cells1 and in this way check growth1 but it seemed to have no effect until the amount was increased to #be grams per #ajj cc of bouillon4 ,in this solution growth appeared as soon as with the weaker solutions1 but there was a smaller amount4 ,in the #be to #dj gram solutions there was less development as the amount of sugar increased4 ,in the #gj and #ge gram solutions growth was delayed one day in its appearance4 ,in the #hj1 #he1 and #ij gram solutions growth was delayed two days1 the colonies growing submerged at first1 but after a time forming on the surface4 ,the mycelium remained very thin1 but a thick layer of spores formed4 ,from this point on the amounts were increased by #aj grams up to #bjj4 ,the development became slower and less successively until #agj grams were added4 ,in this case a small colony appeared on the surface in seven days1 but seemed to grow less after that4 ,the solutions were held1 and in time crystals separated from the thick sirups4 ,after two months dry-looking colonies developed along the edges1 forming a ring1 and some formed on the surface1 these occurring also in the flasks containing #agj1 #ahj1 #aij1 and #bjj grams of sugar per #ajj cc4 ,the colonies were a dull greenish drab in spots1 the remainder being white4 ,for the yeast the #hj-;gram solution of sugar was the strongest in which any development took place4 ,,spices4 ,experiments to determine the value of the spices as antiseptics were made1 using water infusions1 acetic-acid extracts1 and oil extracts4 ,,water ,,infusions4 ,in making the water infusions #bj grams of the whole spices1 with #bjj cc of water1 were boiled for forty-five minutes4 ,this is approximately the length of time that the spices are cooked in the ketchup in the factory4 ,the liquid was then filtered and from #j4a to #e cc of the filtrate was used in #aj cc of tomato bouillon4 ,the same organisms were used as in the former experiments4 ,the tests showed that cinnamon and cloves were the strongest antiseptically4 ,these checked growth when used in small amounts1 but it required #c cc of the cinnamon and #a cc of the cloves to inhibit the growth of the mold4 ,mustard1 paprika1 and cayenne pepper checked growth also1 but #e cc1 the highest strength used1 did not inhibit growth4 ,the ginger1 mace1 and black pepper had no apparent effect in the quantities used4 ,the effect of the spices on the development of the yeast was somewhat different from their effect on ,penicillium4 ,the cinnamon showed the strongest action1 #c cc being effective1 whereas #e cc of the cloves was required4 ,the cayenne pepper came next in effectiveness1 and after that the black pepper4 ,the ginger1 mace1 and mustard solutions had no effect in the strengths used4 ,the remainder of the spice infusions were kept in glass-stoppered bottles in the laboratory1 and in a few weeks' time there was a coating of mold formed over the surface of the mace1 the mustard1 and the black and cayenne peppers4 ,the paprika had small1 stunted colonies dotting the surface4 ,at the time that these experiments were made a quantity of the ground spices were placed in large petri dishes and water was added to make a heavy paste4 ,one set of these was inoculated with the mold1 and another set with the yeast1 and all were kept in a warm place4 ,no development of either organism appeared on the cinnamon1 cloves1 or mustard2 on the others a growth first showed in three days4 ,on a normal medium growth appears in twenty-four hours4 ,on the mace1 paprika1 and cayenne pepper the ,penicillium and yeast with which the pastes were inoculated were overgrown in a few days with black mold 7,rhizopus nigricans74 ,,acetic-,,acid ,,extracts4 ,in the manufacture of ketchup acetic-acid extracts of the spices are sometimes used instead of the whole spices1 on account of their supposed antiseptic properties as well as their greater strength and convenience in handling4 ,one minim of the standard acetic-acid extracts is equal in strength to #a grain of the whole spices4 ,the acid extracts obtained included allspice1 celery1 cloves1 coriander1 garlic1 and black pepper4 ,in the tests #j4a1 #j4b1 #j4c1 #j4d1 #j4e1 and #a cc1 respectively1 of the extract was added to #aj cc of tomato bouillon4 ,one set was inoculated with the mold and another set with the yeast4 ,in the case of the mold1 no growth occurred with the allspice and cloves2 the celery checked the growth materially1 there being no indication of mold until the sixth day4 ,normally a fairly strong growth occurs in twenty-four hours4 ,in the solution containing #j4c cc there was only one small colony in thirteen days1 and no further development4 ,in the solution containing the coriander1 the growth in the #j4e cc solution did not appear for three days1 the #a cc solution showing no growth4 ,the garlic had practically the same effect as the coriander1 while the black pepper was stronger1 no growth appearing in the solution containing #j4e cc4 ,the yeast was slightly stronger in resisting the effect of the extracts4 ,no growth appeared with the allspice and cloves2 #j4e cc of the celery and #a cc of the coriander were required to inhibit growth1 and the garlic and black pepper gave similar results1 a weak development occurring in the solutions containing #a cc4 ,,oil ,,extracts4 ,oil extracts of the spices were tested in the same manner as the water infusions and the acetic-acid extracts4 ,the oils were so strong that in order to handle them easily they were mixed with equal volumes of alcohol1 except that the mace1 which was in the form of a paste1 was mixed with two-thirds its volume of alcohol4 ,to #aj cc of tomato bouillon were added #j4a1 #j4b1 #j4c1 #j4d1 and #j4e cc1 respectively1 of the oils of cinnamon1 cloves1 mace1 mustard1 and black pepper4 ,in the case of the mold1 there was no development in the solutions containing cinnamon1 cloves1 and mustard2 in those containing mace and black pepper the development was slower than the normal1 that in the black pepper being more pronounced4 ,on the yeast the effect was similar1 no development occurring in the cinnamon1 cloves1 and mustard1 and a retarded development taking place in the mace and black pepper1 that in the black pepper being the more pronounced4 ,the experiments show that some of the spices1 notably allspice1 cinnamon1 and cloves have decided antiseptic value1 but that the peppers are not as valuable as is generally supposed4 ,the oil extracts have been advocated for use in ketchup instead of the whole spices1 but in quantities which would be useful antiseptically their use would be objectionable1 for when present in approximately the same proportions as are the whole-spice infusions1 the flavor is too strong and masks the more delicate flavor of the tomato4 ,the acetic-acid extracts are more effective than are the water infusions1 and they are not objectionable in the ketchup4 ,,vinegar ,,and ,,acetic ,,acid4 ,an experiment was made to determine the antiseptic value of vinegar and acetic acid4 ,commercial #ej-;grain distilled vinegar was used4 ,it was found that when #cj per cent of this vinegar was added to the tomato bouillon the development of mold was checked and the extent to which it was checked increased with the increased amounts of vinegar4 ,the development in the solution containing #cj per cent of the vinegar was two days later than the normal in starting1 while the solution containing #ajj per cent was eleven days delayed and showed but little growth4 ,an #hj per cent solution of glacial acetic acid was used4 ,one-half of #a per cent added to the tomato bouillon checked growth to the same extent as #cj per cent of vinegar1 and no development occurred when the quantity was increased to #b per cent4 ,experiments were then made in which vinegar was added to the ketchup in proportions varying from #a part in #cb to #a part in #h1 with the result of greatly delaying the appearance of the mold as the proportion increased4 ,with the increase in vinegar it was necessary to add sugar and slightly more spices to overcome the pungency of the acid and thus insure good flavor4 ,the addition of the vinegar to the pulp had the effect of arresting the action of the oxidase and thus the bright color was maintained4 ,the usual custom in factory practice is to add the vinegar near the close of the cooking process otherwise a considerable portion of the acid will be driven off4 ,this practice was followed in the experimental work1 but it has since been found that continued heating in the presence of the acid has some effect upon sterilization1 and therefore the increased amount of vinegar is effective not only because of the additional acid present1 but also because the heating in the after process is thereby rendered more efficacious4 ,this line of experiments gives promise of practical results in producing a ketchup which will not only keep while in the bottle1 but will also keep longer after it is opened4 ,each manufacturer must work out the quantities that could be used with his formula and still retain the character of his goods4 ,,oil4 ,in ketchup manufacturing it is customary1 if an agitator is not used1 to put a small amount of fat in the kettle to check the ebullition during the reduction of the pulp4 ,the amount used in this manner is not sufficient1 however1 to be apparent in the ketchup4 ,brannt,d states that in some factories1 where the trimmings are allowed to accumulate for the season1 they are given liberal doses of oils and condiments when cooked1 in order to disguise their defects1 so that the product can be placed on the market as 8fresh tomato catchup40 ,that the use of oils is increasing is evident from the comparison of the ketchup of the past season with that of former years4 ,d ,brannt1 ,w4 ,l41 ,a ,practical ,treatise on the ,manufacture of ,vinegar1 #aijj1 p4 #dee4 ,when oil is used in ketchup1 it is easily detected under the microscope1 as it appears in the form of shining1 yellow globules which blacken gradually when treated with osmic acid4 ,besides this1 the oil comes to the surface of the ketchup1 where it can be seen readily1 and if considerable oil has been used a distinct layer is formed4 ,when the ketchup has been made for some time1 the oil changes so that the ketchup has a peculiar 8greasy0 odor1 or the oil may be so changed as to give a decidedly rancid smell to the ketchup4 ,oil usually causes a deterioration in flavor and odor1 though some of the ketchups to which it has been added do not spoil readily4 ,olive oil1 cottonseed oil1 and oleomargarine are used4 ,that the oil is not considered one of the regular known ingredients of the ketchup is shown by the failure to declare its presence on the label4 ,to test the antiseptic value of oils in ketchup1 experiments were made1 using olive oil1 cottonseed oil1 and oleomargarine in the proportions of #a part of oil to #a1jjj1 #gej1 and #ejj parts of ketchup1 respectively4 ,the ketchup was made in small quantities1 #b gallons for each experiment4 ,after bottling1 all except the check bottles were inoculated with ,penicillium and kept at kitchen temperature4 ,all spoiled1 and neither the quantity nor kind of oil used had any marked effect in preventing spoilage4 ,that the oils affected the development of the mold was evident4 ,the mold developed first at the junction of the ketchup with the bottle forming a ring which spread gradually over the surface developing a somewhat heavy mycelium4 ,this remained white longer than usual1 spores forming very gradually1 as indicated by the change in color from white to a delicate blue4 ,at the end of three weeks only spots of color appeared on the surface and these were still blue1 though in ordinary development the blue color changes to green in two or three days4 ,another test was made1 using olive oil only1 and in the proportions of #a part of oil to #ejj1 #djj1 and #cjj parts1 respectively1 of the ketchup4 ,reduction was made in a steam-jacketed kettle1 the oil being added when the ebullition of the ketchup was the strongest1 after which the boiling was continued for fifteen minutes4 ,the ketchup was bottled1 unsterilized bottles being used1 then covered loosely with the metal caps4 ,the time required for the ketchup to spoil was longer than in the first set1 but there was not sufficient difference nor enough uniformity in the time to indicate that the use of oil in ketchup is desirable1 even if the change of flavor and odor be not taken into consideration4 ,the average number of days before spoilage for those containing #a part of oil to #ejj parts of ketchup1 was thirteen and two-thirds days2 one has not yet spoiled 7a period of forty-five days71 while the first bottle spoiled in four days4 ,those having #a part of oil to #djj parts of ketchup had an average life of nine and three-fourths days1 the minimum being three days1 and the maximum twenty-six days4 ,those having #a part to #cjj parts of ketchup on an average did not spoil for six and three-fourths days1 the minimum being four days1 and the maximum eleven days4 ,the failure of some of the bottles to spoil1 though similar in every known respect to those which did spoil1 is a feature peculiar to ketchup and is familiar to manufacturers who make careful tests before putting their product on the market4 ,for this reason a rather large number of bottles should be used in a test in order that the results may be approximately accurate and represent general conditions4 ,,study ,,of ,,penicillium ,,in ,,ketchup4 ,penicillium is a plant which is distributed widely and apparently is able to grow wherever organic matter is found1 though flourishing best when the material contains acid4 ,it causes loss in canneries1 breweries1 distilleries1 etc41 the only use made of it being in the manufacture of ,roquefort cheese1 the immature cheese being inoculated with the conidia for the effect the mold produces in the maturing process4 ,illustration3 ,fig4 #a4--;,conidia1 ,normal ,size and in ,various ,stages of ,germination1 ,some with ,branching ,hyph 7 #cbe74 ,illustration3 ,fig4 #b4--;,conidiophore1 ,showing ,unusually ,large ,development of ,conidia1 from ,culture in ,moist ,chamber 7 #cbe74 ,,penicillium4 ,illustration3 ,fig4 #a4--;,conidia and ,hyph from ,culture in ,experimental ,ketchup ,containing ,one-sixteenth of ,one ,per ,cent of ,sodium ,benzoate 7,x #cbe74 ,illustration3 ,fig4 #b4--;,conidia and ,hyph from ,cultures in ,experimental ,ketchup ,containing ,one-tenth of ,one ,per ,cent of ,sodium ,benzoate 7,x #cbe74 ,,cultures ,,from ,,ketchup ,,preserved ,,with ,,sodium ,,benzoate4 ,,development4 ,in developing1 the mold forms a white felt-like mass1 covering the medium on which it is growing2 then as development proceeds1 it changes to bluish-green1 and finally to a darker1 duller color4 ,the change in color is accompanied by a change in structure1 the surface becoming powdery in appearance1 a slight current of air being sufficient to dislodge a cloud of fine dust4 ,this fine dust is formed of small1 spherical bodies1 the spores or conidia 7from the ,greek meaning dust74 ,these need no resting period1 but are able to develop at once4 ,when the conidia lodge on a moist substance they swell to a much greater size and then send out a tube from some part of their surface4 ,the tube lengthens and septa form1 dividing the tube into sections1 or cells4 ,at the same time branches are sent out1 which again form other branches4 ,the original conidium sends out a second branch shortly after the first one1 and usually from the opposite side1 and may even send out a third one4 ,the formation of the septa and the subbranching goes on in all1 so that in a short time the branches mat together and form a felt-like cover4 ,,reproduction4 ,after a shorter or longer period of development1 dependent on the conditions1 branches are sent perpendicularly from the substratum1 and into the air4 ,these branches cease their growth in length1 sending out branches near the tip1 which take the same general direction as the original branch4 ,each of these subbranches is called a sterigma 7from the ,greek word meaning support74 ,in vigorous development the sterigmata may form secondary branches1 the whole forming a tassel-like arrangement4 ,the tip of a sterigma enlarges1 a septum forms around the enlargement1 cutting it off from the sterigma1 and forming a conidium4 ,the sterigma develops to the original length and another conidium is formed1 the operation being repeated many times1 thus forming a chain of spores4 ,as the other sterigmata are also forming conidia in the same manner1 a series of these chains is formed close together4 ,after the cessation of conidial development1 the filament below the sterigmata is disorganized1 setting free the conidia4 ,the filament and head together are called the conidiophore 7,greek1 dust-bearer74 ,penicillium forms spores sexually1 but the conditions for their formation are unknown4 ,brefeld obtained them by growing the mold on damp bread placed between two glass plates1 and excluding the air4 ,lindner obtained carpospores on a wort gelatin culture in a petri dish1 from which the air was excluded4 ,the writer has tried various methods for obtaining carpospores1 but so far without success4 ,moist chambers were used with various media1 excluding the air4 ,the development of the mold is seemingly dependent on the amount of air in the chamber at the time of sealing4 ,after the air is exhausted1 the conidiophores assume fantastic forms1 developing only one or a few sterigmata1 and on these one or few conidia4 ,in other cases the conidiophores are fascicled1 in no cases1 however1 forming the conidia as luxuriantly as when air is supplied4 ,the hyph become clear1 much vacuolated1 and develop more septa1 and some of the cells become much enlarged4 ,an enlarged cell will often contain two or three septa1 thus forming cells that are not larger than disks4 ,in cultures from which the air was excluded from the start1 no development took place4 ,in test-tube cultures sealed with paraffin after twenty-four hours1 the mold developed on the surface of the gelatin1 forming a felted white mass1 but no conidia nor carpospores were formed4 ,,growth ,,in ,,ketchup4 ,the form of ,penicillium which was used in the experiments was isolated from ketchup in which it grew luxuriantly4 ,when conidia are first formed on the ketchup1 they are a delicate blue in color2 they then become bluish green1 then green1 and finally olive4 ,the development of the color of mold growing on ketchup is practically the same as when grown in wort1 tomato bouillon1 pea bouillon1 or gelatin made with these solutions as a basis4 ,in ketchup containing sodium benzoate1 the blue color appearing first remains for a long time1 and in old cultures the mold is a dull drab1 not olive1 as in normal development4 ,in ordinary ketchup made without a preservative1 the mold forms a heavy1 wrinkled mycelium1 showing a large development of conidia4 ,in the bottles of ketchup1 the mold pushes down into the ketchup1 becoming entirely submerged1 a clear liquid covering the mold and separating it from the ketchup4 ,this occurred in more than one hundred bottles4 ,no secondary mycelium formed on the surface of the liquid1 a method of development which frequently occurs in ordinary media when a mass of mold is submerged4 ,an exception to this was shown in ketchup which had developed the mold in the laboratory4 ,the bottles were then put in the refrigerator for two weeks4 ,during this time scarcely any development took place2 but after they were again placed in the laboratory1 the mycelium pushed down into the ketchup and a new1 very thin mycelium developed on the surface4 ,the filaments when seen under the microscope were swollen1 had irregular outlines1 and a comparatively smaller number of septa1 and were filled with a coarsely granular protoplasm4 ,the ends were blunt and misshapen and the sterigmata were irregular1 tending more toward a fasciculated arrangement1 and forming fewer conidia4 ,the filaments from the vinegar and acetic acid media had the same appearance as those developed on ketchup1 but had a smoother outline4 ,,temperature ,,tests4 ,the limits for the germination of ,penicillium1 as given by ,w4 ,j4 ,sykes1,e are #b to #dc ,c4 7#ce to #aaj ,f471 and the most favorable temperature #bb to #bf ,c4 7#gb to #gi ,f474 ,this author states also that according to ,pasteur the dry spores retained their vitality at #ajh ,c4 7#bbf ,f471 but that they were soon killed when immersed in boiling water4 ,klcker,f quotes ,pasteur as saying that the conidia are killed if exposed to a temperature of #abg to #acb ,c4 for half an hour1 but that they retain life at #aai to #aba ,c4 ,e ,principles and ,practice of ,brewing1 #aijg1 p4 #bhd4 ,f ,ibid41 p4 #bha4 ,a series of tests was made to determine the thermal death point of the moist and dry conidia of the ,penicillium used in the experiments1 a young1 vigorous development on ketchup being used4 ,the flasks were kept under observation for a month after the tests were made1 as in many cases a development does not occur in the usual time4 ,the high temperatures applied for longer periods of time were tried first1 but both temperature and time were reduced as results from the series were obtained4 ,only the conditions obtaining in the final tests are given in the table4 ,it was found that the ,penicillium used did not have the high resistance supposed4 ,the tests were made in small flat-bottomed #aj-;cc flasks1 tomato bouillon being used for the tests on moist conidia4 ,the bouillon was used so as to have the conidia in a nutritive medium after the test was made1 without transferring4 ,the time for those at #ajj ,c4 was estimated from the time of ebullition4 ,at the end of the specified time1 the flasks were cooled promptly under running water4 ,as the flat bottoms gave comparatively large surface1 the heating and the cooling could be effected in a short time4 ,for the tests below #ajj ,c4 a vessel of water was heated to the desired temperature1 and the flasks were immersed in it and shaken constantly4 ,the dry conidia were placed in test tubes which were immersed in boiling water for the desired time and cooled under running water1 after which #aj cc of sterilized tomato bouillon was added4 ,after determining the death point in this manner and finding it to be much lower than had been supposed1 it was decided to make the test again1 but using ketchup as the medium4 ,ten grams of ketchup were sterilized1 then inoculated from a vigorous growth of mold1 and tested with a set in which the tomato bouillon was used4 ,for those below #ajj ,c4 the two flasks which were to receive the same temperature were held in the vessel of water at the same time1 so that as nearly as possible the treatment would be identical4 ,the following results were obtained3 ,thermal death point of moist and dry conidia of ,penicillium4 ,,penicillium ,,in #aj ,,cc ,,of ,,tomato ,,bouillon4 ---------------------------------------- -------------------------- ,no4 of ,temperature4 ,time of ,time before ,period of observation experiment4 heating4 germination4 and developments4 ---------------------------------------- -------------------------- ,c4 ,minutes4 ,days4 #a #he #c ,dark strings from spores2 #i days2 no development4 #b #hj #a #c #ge #a #d #gj #e #e #fe #e #c ,dark strings running from spores2 #i days2 growth normal1 spots on surface4 #f #fj #e #c ,do4 #g #ee #e #c ,do4 ---------------------------------------- -------------------------- ,,penicillium ,,in #aj ,,cc ,,of ,,ketchup4 ---------------------------------------- -------------------------- #a #ajj #c #b #ajj #b #c #ajj #a #d #ajj #e #ajj ,instant4 #f #he #b ,colonies on sides2 #h days2 surface covered1 green4 #g #hj #a #b ,do4 #h #ge #a #b ,do4 #i #gj #e #h ,colony on surface4 #aj #fe #e #i ,do4 #aa #fj #e #c ,colonies on sides2 #h days2 surface covered1 green4 #ab #ee #e #d ,do4 #ac #b ,ring around sides2 #c days2 surface nearly covered4 ---------------------------------------- -------------------------- ,,dry ,,conidia4 ---------------------------------------- -------------------------- #a #ajj #aj #d ,rough appearance1 like that in ketchup4 #b #ajj #ae #d ,do4 #c #ajj #bj #g ,slight growth4 #d #ajj #be #aj ,growth barely perceptible4 #e #ajj #cj #aj ,do4 #f #ajj #ce ,conidia stained readily1 showing they were dead4 ---------------------------------------- -------------------------- ,,yeast4 ---------------------------------------- -------------------------- #a #ee #e #b ,wrinkled film2 liquid turbid4 #b #fj #e #b ,do4 #c #fe #e #b ,thin1 smooth film2 liquid clear4 #d #gj #e #e #ge #e #f #ajj ,instant4 ---------------------------------------- -------------------------- ,the moist heat was very effective in destroying the vitality of the conidia of ,penicillium1 the death point being #bg ,c4 higher than the maximum temperature for germination as given by ,sykes4 ,the heating was more effective in destroying germs when applied to bouillon than to ketchup1 no development taking place for any temperature above #fe ,c41 even when applied for a short time4 ,in the ketchup the lower temperatures for the longer periods of time were more effective in checking the development1 even though they did not destroy the vitality4 ,in the ketchup1 with the exception of ,nos4 #i and #aj1 the colonies started invariably along the sides of the flasks4 ,the greater access of air to those on the sides would account for this4 ,the conidia on the sides of flasks ,nos4 #i and #aj must have been destroyed1 as no development took place in either case except in the center of the surface4 ,the dry conidia were destroyed at #ajj ,c4 when heated for thirty-five minutes2 they did not reach a normal development in any case1 even when heated for only ten minutes1 many of the conidia being destroyed by this treatment4 ,where development failed to take place1 the conidia were stained with a water solution of eosin1 so as to be sure that the effect was death1 and not an arrested development4 ,the results of the tests do not agree with those obtained in factory practice1 where the ketchup is cooked at #ajj ,c4 for at least forty minutes and sometimes for fifty or fifty-five minutes1 depending on the consistency of the pulp4 ,,histological ,,structure ,,of ,,ketchup4 ,in ketchup are found parts of all the various tissues of the tomato broken into fine pieces by the action of the cyclone4 ,although the sieves take out the seeds1 skins1 and any large pieces1 particles of the various tissues are present in size sufficient for identification4 ,among the distinctive features are the red crystalline bodies in the parenchyma1 which serve to a certain extent to distinguish the parenchyma from that of other plants which might be used for adulteration1 and serve also to differentiate the natural from the artificially colored ketchup4 ,some of the red dye used colors all protoplasm indiscriminately1 even that of the fungi present1 and as a colored ketchup is usually poor stuff1 containing many fungi1 the mold filaments1 yeast cells1 and bacteria receive their share of the color4 ,other red dye used is in the form of fine powder1 which does not go into solution1 but is distributed as irregular particles which are distinct from the red crystalline bodies4 ,good ketchup made from whole tomatoes has a clean appearance readily distinguishable under the microscope2 but the poor ketchup has usually a superabundance of fungi present1 fully developed colonies of mold1 many forms of conidia1 besides yeast-like cells1 and different forms of bacteria4 ,all of these may be dead1 but neither preservatives nor dosage of odorous spices can disguise their presence4 ,in some of the ketchup examined1 which was put up in attractive form and labeled as being made from the whole tomatoes1 and which had the appearance and odor of good ketchup1 the microscope showed the presence of such quantities of fungi as to leave no doubt that the tomatoes were spoiled when cooked4 ,it is presumable that some of the dealers placing this sort of stuff on the market do not know its condition themselves1 and either buy their pulp from other factories or trust its manufacture to employees whose only care is that the ketchup shall have a bright color and shall 8keep40 ,some of the mould filaments and conidia are distorted in the same way as those of the ,penicillium are when grown in ketchup to which sodium benzoate has been added4 ,the ketchup made from sound tomatoes and manufactured in a cleanly manner has practically no fungi present4 ,the ketchup that was used in these experiments was made at different times during the season and was of this character1 no bottle examined showing mold filaments when first opened4 ,,microscopic ,,examination ,,of ,,some ,,commercial ,,brands4 ,in examining ketchup the color1 odor1 amount of discoloration1 presence of foreign tissue1 foreign coloring matter1 oil1 and fungi were determined4 ,if no preservative was mentioned1 some of the ketchup was put in petri dishes and inoculated with ,penicillium to determine whether growth could take place4 ,the following examinations are reported1 as they represent some of the best known brands on the market3 ,no4 #i4--,opened ,september #b1 #aijg2 age unknown2 pint bottle2 no preservative mentioned2 not spoiled ,july #f of following year4 ,this ketchup was guaranteed to be made from fresh1 ripe1 tomatoes by a new process4 ,the color is an unnatural red1 has not faded1 and the odor is good4 ,the microscope showed the presence of much refuse1 and large quantities of fungi1 whole colonies of molds1 the filaments distorted1 many yeast cells1 and bacteria4 ,the red color was not confined to the red crystalline bodies1 as is the case in ripe tomatoes1 but the whole of the protoplasm of the cells1 including the nucleus and nucleolus was red1 as were also most of the mold filaments and yeast1 indicating the presence of considerable artificial coloring matter4 ,the structure indicated that the stock had been manufactured from 8trimmings10 and further1 that they were not fresh when used1 but had fermented4 ,there was no oil present4 ,the 8new process0 is a success in keeping ketchup1 as no preservative is mentioned4 ,the price was #bj cents4 ,no4 #aab4--;,another bottle of the same brand of ketchup2 examined in ,april1 #aijh2 presumably manufactured in #aijg2 one-twelfth of #a per cent of sodium benzoate declared on label2 a bright red2 guaranteed to be from fresh ripe tomatoes and uncolored4 ,the microscope showed no dyeing of the tissues1 few fungi1 and no extraneous matter4 ,the price was #bj cents4 ,no4 #ag4--,opened ,september #bh1 #aijg2 age unknown2 a pint bottle2 sodium benzoate declared on supplemental label1 no amount being stated2 reddish brown color1 badly discolored on top2 greasy odor2 not spoiled ,july #f1 #aijh2 refuse present2 large amount of oil2 many fungi2 the mold filaments enlarged and distorted4 ,the price was #ae cents4 ,no4 #aji4--;,another bottle of the same brand examined in ,april1 #aijh2 presumably manufactured the preceding year2 had one-tenth of #a per cent of sodium benzoate2 not spoiled ,july #f1 #aijh2 reddish brown color1 discolored near top2 greasy odor4 ,this was practically the same as the first bottle examined1 had fewer mold filaments1 but many bacteria4 ,no4 #ah4--,opened ,september #bh1 #aijg2 age unknown2 pint bottle2 no preservative mentioned2 not spoiled ,july #f1 #aijh4 ,a neck label stated that it is made from sound ripe tomatoes and uncolored4 ,color reddish brown2 greasy odor2 many oil globules2 too many mold filaments and bacteria for sound tomatoes4 ,price #bj cents4 ,no4 #aac4--;,another bottle of the same brand examined in ,april1 #aijh2 said to have been manufactured in #aijh2 no preservative mentioned2 not spoiled after standing open for seventy days2 same as ,no4 #ah in color and odor2 oil and many fungi again present4 ,no4 #aj4--,opened ,september #b1 #aijg2 age unknown2 half-pint bottle2 no preservative mentioned2 not spoiled ,july #f1 #aijh4 ,a neck label #b inches in height guaranteed the highest quality2 an extra label lower down on the neck stated the product to be the natural color1 and made from fresh1 ripe tomatoes2 the regular label carried the brand1 manufacturer's name1 etc4 ,color brown2 sweetish odor2 colonies of mold2 distorted filaments2 many bacteria2 a few small oil globules4 ,price #be cents4 ,no4 #ajf4--,same brand2 pint bottle2 examined in ,april1 #aijh2 said to be manufactured in #aijg2 color red1 discolored near surface2 #b-;inch neck label in addition to regular label2 no preservative mentioned2 did not spoil in seventy days2 oil globules2 particles of red1 amorphous matter2 whole colonies of mold1 as well as fragments of filaments2 teeming with bacteria4 ,no4 #gg4--;,different brand1 but same manufacturer as ,nos4 #aj and #ajf2 age unknown2 pint bottle2 one-twelfth of #a per cent of sodium benzoate declared2 opened ,december #a2 placed in incubator at #ie ,f4 for a month2 not spoiled ,july #f2 color reddish brown2 greasy odor2 oil globules1 many mold filaments1 and bacteria present4 ,price #bj cents4 ,no4 #ajg4--,third brand from same manufacturer as preceding2 said to be manufactured in #aijg2 half-pint bottle2 one-twelfth of #a per cent of benzoate of soda declared2 layer of oil on surface2 sweet odor2 reddish-brown color4 ,oil globules prominent feature microscopically1 whole colonies of distorted mold were present1 and sample contained many different forms of bacteria4 ,price #aj cents4 ,no4 #ad4--,opened ,september #b1 #aijg2 age unknown2 no preservative mentioned2 not spoiled ,july #f1 #aijh2 half-pint bottle2 color red2 good odor2 few bacteria2 free from refuse4 ,price #be cents4 ,no4 #ajh4--,same brand as ,no4 #ad2 said to be manufactured in #aijg2 pint bottle2 one-tenth of #a per cent of benzoate of soda declared2 color red2 good odor2 few fungi2 clean and free from refuse4 ,no4 #cc4--,opened ,october #bd1 #aijg2 age unknown2 one-tenth of #a per cent of benzoate of soda declared2 spoiled ,november #a2 pint bottle 7#ad ounces72 sweetish odor2 brown color2 many molds1 yeast and bacteria4 ,price #aj cents4 ,no4 #aad4--,same brand as ,no4 #cc2 said to be manufactured in #aijg2 opened in ,april2 not spoiled in seventy days2 many molds1 yeasts1 and bacteria2 some green tissue1 and filaments of alg4 ,the price was #aj cents4 ,,summary4 #a4 ,the experiments made during the season of #aijg on the manufacture of tomato ketchup without chemical preservatives were conducted under factory conditions and upon a commercial scale4 ,the results prove that such a ketchup can be made and delivered to the consumer in perfect condition2 the product in question having already stood ten months1 unopened1 without showing the slightest indication of spoilage4 #b4 ,the product is of excellent consistency1 flavor1 and color4 ,the formula employed regularly in the factory where the experiment was conducted was used1 but other recipes could be adapted without changing the character of special brands4 ,in the manufacture of such a product the following precautions were observed3 7a7 ,whole1 sound1 ripe tomatoes and high-grade salt1 sugar1 vinegar1 and spices were used2 care and cleanliness were observed at every step of the preparation1 and the preservation accomplished by heat in the following manner3 ,the pulp was cooked in a steam kettle for about forty minutes1 until the mass was reduced to about one-half its volume4 ,additional processing after bottling did not appear to be necessary to keep the ketchup before opening1 and had no effect in these experiments in delaying spoilage after opening4 7b7 ,ketchup was bottled directly from the cooker at a temperature of #bje ,f4 in bottles prepared in two ways3 7#a7 ,sterilized in a steam chamber at #bcj ,f42 7#b7 ,washed in hot water1 rinsed1 and heated to #aij ,f4 in a dry heat for at least thirty minutes4 ,ketchup was also bottled after the usual process of sieving at #afe ,f4 in bottles prepared in a similar manner4 ,the corks for all bottles were sterilized in a paraffin bath at #bgj ,f4 ,the same ketchup which was bottled at #afe ,f4 was also given subsequent processing at #aij ,f4 and #bab ,f4 for twenty and forty minutes4 ,all have kept without spoilage4 #c4 ,some of the condiments have a limited antiseptic value1 but can not be depended upon to prevent spoilage in the quantities used for flavoring4 ,while sugar and vinegar can be added in such amounts as to delay the appearance of molds1 and cinnamon and cloves can be depended upon to check deterioration to some extent1 these condimental substances have only an incidental value for this purpose4 #d4 ,the spoilage of ketchup after opening depends more upon the temperature of the place in which it is kept than on any variation in the manner of processing4 ,fresh ketchup held1 after opening1 at a temperature of #ie ,f4 kept for five days on an average without any trace of mold appearing2 at #gb it kept for six days2 at #fg for eight days2 about #df 7refrigerator71 fourteen days2 and at from #cj to #fj for twenty-seven days4 ,these figures represent the time at which the first trace of spoilage occurred in the neck of the bottle--had this been removed the figures would be much increased--and by no means represent the maximum time during which the ketchup could have been used1 the maximum figures1 even under these conditions of observation1 varying from eight to fifty-eight days4 ,the keeping of the ketchup in warm storage at #gj for one hundred and fifty days before opening hastened the average time of spoilage after opening about one day4 ,the advisability of using small containers1 to get the best results with a first-class ketchup1 is apparent4 #e4 ,sodium benzoate1 even when used in the proportion of #j4a per cent1 is not always effective1 and has an injurious effect upon the living matter of the molds1 shown by the distortion and swelling of the filaments1 which are filled with a coarse granular protoplasm containing much fat4 #f4 ,artificially colored ketchup can be detected under the microscope by the fact that certain tissues1 normally colorless1 are dyed red1 or by the presence of fine1 red1 amorphous particles which do not go into solution4 #g4 ,ketchup made from whole ripe stock in a cleanly manner gives a clean appearance under the microscope1 but few molds1 yeasts1 and bacteria being present4 ,on the other hand1 ketchup made from trimming stock1 or from tomatoes that have been allowed to spoil1 contains immense quantities of these growing organisms which may be killed in the process of manufacture1 but still give proof of the character of the material used4 ,ketchup as ordinarily made from trimming stock should1 therefore1 be designated1 so as to differentiate it from that made from sound fresh tomatoes1 as the two products are radically different4 ,this exactness in labeling is due no less to the manufacturer than to the consumer1 as it is impossible to make the superior product in fair competition with the inferior one1 other conditions being equal1 unless the two are properly designated1 there being naturally some difference in the price4 ,transcriber's ,notes3 ,in the text version1 italics are represented by underscores4 ,missing or incorrect punctuation has been repaired4 ,the following corrections have been made to the text3-- p4#h4 ,a majority of the manufacturers employ word1 has been changed to ,a majority of the manufacturers employ the word4 p4#bh4 one has has1 the duplicate has been removed4