A. W. Bitting

“ The fundamental basis for the microscopic examination of any food product must depend upon the structure of the material which enters into its composition. Any attempt to determine an abnormal condition, such as decomposition, without a knowledge of the normal, must necessarily be of little value. There is some work which can be done in a mechanical manner by almost anyone capable of looking through a microscope, and if the work is properly supervised, it may have a value, but the lines along which this can be done are very limited. ”

“ On this year’s ketchup the labels make fewer claims, generally merely stating that it is “tomato ketchup,” which is true whether made from whole tomatoes or refuse. The brand is in most cases the guaranty for good quality. It is not safe to judge the quality by the price, for, though usually good quality can not be expected unless the higher price is paid, some of the high-priced ketchup when placed under the microscope has proven to be a very inferior product. ”

“ With the quantities of tissue above stated, 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 found, on the other.” The organisms in pulp or ketchup are dead, or, if alive, do not possess such phenomenal power of multiplication, therefore, the shaking should be conducted with sufficient energy and for a sufficient time to insure their separation from the tissue. ”

“ This line of experiments gives promise of practical results in producing a ketchup which will not only keep while in the bottle, but will also keep longer after it is opened. Each manufacturer must work out the quantities that could be used with his formula and still retain the character of his goods. ”

“ The cells of the tissues are torn to shreds, their contents discharged, molds are broken into hundreds of fragments, and a ketchup may be made to have the appearance of being made from poor material. The finishers have large capacity and will work on either light or heavy goods, but like the cyclone, must be handled with judgment, not attempting to force the last ounce through the sieve. ”

“ Some of the red dye used colors all protoplasm indiscriminately, even that of the fungi present, and as a colored ketchup is usually poor stuff, containing many fungi, the mold filaments, yeast cells, and bacteria receive their share of the color. Other red dye used is in the form of fine powder, which does not go into solution, but is distributed as irregular particles which are distinct from the red crystalline bodies. ”

“ Where the black rot occurs on tomatoes, the tissue is hardened like cork, and if not removed on the sorting belt, is broken into small pieces by the cyclone, and appears as black specks in the ketchup, these being readily perceived by the naked eye. The white rot forms soft spots, which, though not so prominent as the black, carry much more contamination, as, apart from the bacteria, yeasts, and molds present, they are often swarming with Protozoa. ”

“ The making of tomato ketchup consists essentially in reducing tomatoes to pulp, removing the skins, seeds, hard parts, and stems, adding salt, sugar, condiments, and vinegar to suit the taste, and cooking to a proper consistency. The methods and practices of the various manufacturers differ, and the difference between the best and the poorest procedure corresponds to that between the best and the worst ketchup. No single factory has all of the best methods at every step of manufacture. ”

“ In all cases of soft rot, there is much more contamination carried, as the organisms are small and a greater number present in a given area. Whenever the inner tissue of tomatoes is exposed, organisms develop rapidly, the forms varying with the locality and the conditions in the pulp. Some of these organisms may survive the treatment of the pulp when converted into ketchup, or the original organisms may be destroyed, and a different set gain access and develop, but in either event all the organisms alive or dead which were present at the period of manufacture are found in the ketchup. ”

“ As a result, it is not uncommon to see an inch or more of pulp in the bottom of a car at the end of shipment, caused by the blowing out of the barrel heads from fermentation. The sanitary condition of the factory may be poor, the handling of the goods be unclean, the spices be the refuse from the spice houses, the sugar be of the cheapest grade, and the bottles be only rinsed or be used without even that precaution. The ketchup is a concoction so heavily spiced with hot spices that the tomato flavor is lost and might as well be anything else. ”

“ In the factory many refinements are necessary to make a commercial article which will attract the eye as well as satisfy the sense of taste. The usual dark colored, rough, home-made article will not command a sale over a grocer’s counter alongside of that made in a modern commercial kitchen. Here, sorting tables, washing machine, scalder, cyclone for pulping, steam-jacketed kettle, tanks with coils, or vacuum pan for cooking, finishing machine, bottle washing, and filling machine, are all necessary. ”

“ Whole or ground spices, or acetic acid or oil extracts of the spices may be added to the pulp in such proportion as the particular brand demands. The spices most used are cloves, cinnamon, mace, and cayenne pepper; but paprika, pepper, mustard, cardamon, [11] coriander, ginger, celery, and allspice are used by some manufacturers. When whole spices are used, it is the practice to suspend them in a cloth bag or a wire basket and to take them out after boiling. They tend to darken the color of the ketchup, a result considered undesirable by some. ”

“ The cell cavity is often filled with bacteria, so that the effect of the rotting can not be seen until the cells have been washed thoroughly. These bacteria have been mistaken for the particles left by the decomposition of the cell contents. The vascular bundles are surrounded usually by small parenchyma cells which do not separate readily from the strand in the healthy tissue, but in the decayed tissue the vessels can be seen clearly, free from other tissue. ”

“ When conidia are first formed on the ketchup, they are a delicate blue in color; they then become bluish green, then green, and finally olive. The development of the color of mold growing on ketchup is practically the same as when grown in wort, tomato bouillon, pea bouillon, or gelatin made with these solutions as a basis. In ketchup containing sodium benzoate, the blue color appearing first remains for a long time, and in old cultures the mold is a dull drab, not olive, as in normal development. ”

“ 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 condition. When one basket is set on the edges of two or three others in stacking, there is always cutting of a few of the top fruit, the movement in riding causes others to gradually settle and pack into the cone shape of the bottom, so that if they be held for a day or more, there will be loss of juice, consequent growth of mold, and contamination of the sound fruit from the infected. ”

“ Good ketchup made from whole tomatoes has a clean appearance readily distinguishable under the microscope; but the poor ketchup has usually a superabundance of fungi present, fully developed colonies of mold, many forms of conidia, besides yeast-like cells, and different forms of bacteria. All of these may be dead, but neither preservatives nor dosage of odorous spices can disguise their presence. ”

“ The oil extracts have been advocated for use in ketchup instead of the whole spices, but in quantities which would be useful antiseptically their use would be objectionable, for when present in approximately the same proportions as are the whole-spice infusions, the flavor is too strong and masks the more delicate flavor of the tomato. The acetic-acid extracts are more effective than are the water infusions, and they are not objectionable in the ketchup. ”

“ A fairly acid tomato imparts more flavor and needs less vinegar in the finished product. The fleshy portion of the tomato gives the body, but the pulp about the seeds furnishes the characteristic flavor.
The collecting of tomatoes in the field should be done at short intervals so that the fruit may be taken when in prime condition. Where picking is done at too wide intervals, there is a tendency to take fruit that is only colored and not really ripe, and for some to be left and become over-ripe. ”

“ The chromoplasts are not affected by rotting to the same extent as are the other constituents of the cell; they can be found floating free in the debris from rotted cells, still retaining considerable color. They lose their color gradually, in some varieties much more rapidly than in others. In stored pulp which has fermented, the color may be faded to a dull yellowish brown. In tomatoes intended for ketchup where a bright red color is desirable, care should be used in the selection of a variety having the chromoplasts bright, properly oriented, and in sufficient quantity. ”

“ The tomatoes should be home-grown, of a red variety having the minimum of yellow and purple color, be picked when ripe, and delivered to the factory promptly without mashing. All tomatoes should pass over an inspection table, the rotten and otherwise unfit fruit should be discarded, and the green tomatoes should be returned to crates to ripen. The stems should be removed when the best color is desired, and the tomatoes should be thoroughly washed to remove dirt and mold. ”

“ It is known that the surface of plants is covered by a variety of bacteria and other fungi that remain dormant under unfavorable conditions, but that these become active when the food which is invariably present is rendered available by access of moisture, either dew or rain, or the rupture of the host, etc. ”

“ The color is normally dirty brown.
Between these two extremes are all grades, those for which whole tomatoes, unsorted, are used, those for which trimming stock is worked up promptly during the canning season, and those made from stock of unknown history. Some manufacturers work under good and some under poor sanitary conditions. 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 ketchup ”

“ 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 cell. The cuticle differs in chemical composition from the rest of the cell walls, being impervious to water, and resisting rotting longer than do the cellulose walls. As it is continuous over the whole of the fruit, the skin can be readily separated from the other tissues. ”

“ The effect of sugar was tested on both the mold and the yeast by adding it to tomato bouillon. It was supposed that a low percentage of sugar like the salt would plasmolyze the cells, and in this way check growth, but it seemed to have no effect until the amount was increased to 25 grams per 100 cc of bouillon. In this solution growth appeared as soon as with the weaker solutions, but there was a smaller amount. In the 25 to 40 gram solutions there was less development as the [24] amount of sugar increased. In the 70 and 75 gram solutions growth was delayed one day in its appearance. ”

“ Ketchup is made in the home with very simple apparatus; a colander or sieve for breaking and straining the pulp, and a copper, porcelain, or earthen kettle for cooking, being all that is necessary. The cooking of the tomatoes with the spices, sugar, vinegar, etc., is generally done slowly, until a heavy body is obtained, which results in a dark color, but insures sterility of the product when it goes into the container, and also contributes to keeping quality after it is opened. ”

“ 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 product. Whole selected fruit is used, cleanliness is maintained at every point, the best grades of spices, vinegar, granulated sugar, and salt are added for flavoring, and the bottles are carefully washed. ”

“ There are certain steps in the process of manufacture which also influence the number of organisms which may be counted. 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 60 per cent, and ketchup may vary from a thin watery consistency to one which is so heavy that it will scarcely flow from the bottle. ”

“ In counting molds, no distinction is made as to whether a small bit is in the field or a large mass. In making a mount for molds, the solids generally tend to stay in the center of the field while the liquid tends to run to the edge. The fields selected may therefore give a high or low result determined by their location. One examiner desiring to favor the manufacturer may select the outer part for most of the fields, while another, making the examination for the buyer, who may wish to make a rejection, may reverse the operation. ”

“ The keeping qualities of a mild ketchup will depend far more upon the sterilization than most manufacturers realize. It is easy to make almost any ketchup apparently keep while the bottle is unopened. The spoilage after opening is most often observed to be due to mold which has been assumed to come from infection from the air. As a matter of fact, this is nearly always due to spores which have been held in abeyance, due to lack of air while in the bottle, and which begin growth as soon as conditions are favorable. ”

“ Some manufacturers leave the stem on to give flavor.
WASHING. The washing is the most important mechanical operation in making pulp or ketchup in order to get a clean product. It is the weak spot in most factories, but fortunately is the one that can be most easily changed. The ideal washer is one that first receives the tomatoes in a tank, holding them for a sufficient length of time to soak and to loosen the dirt, and then submits all parts to a thorough spray under strong pressure. Most washers do not meet these requirements. ”

“ It is stated that it is believed that it is possible for manufacturers to keep within 12,500,000 bacteria per cc in the pulp and 25,000,000 in ketchup. The number present is expressed in terms per cc though the yeast and spores are expressed in 1-60 c mm. Possibly bacteria to the lay mind mean something dangerous, so by expressing the numbers in millions they appear appalling. Yeasts and spores are not so generally associated with dirt and disease so that by giving them a small unit, only 1-60,000 part of a cc, they may seem much less offensive. ”