A. W. Bitting

“ 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. ”

“ 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. ”

“ 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. ”

“ 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 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. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ When the tomato is converted into pulp, every particle is exposed to the air for a very short time—long enough to make some slight change. The change is most marked in pulp from raw stock and least in that which has been well heated. It naturally follows that ketchup made promptly from whole stock will have the best color, that from canned tomatoes next, then canned pulp, and lastly, that from trimming stock. Pulp allowed to stand hot for too long a time will have a brownish color like stack burning. ”

“ For example, a tomato juice with an initial count of 10,000,000 if evaporated to one-half its volume will have more than twice the number of organisms estimated in the original. The pulp is composed of both liquid and solids and part of the liquid portion only is driven off by evaporation, leaving in the residue a different proportion to the solids. As the organisms can be counted only in the liquid portion, it is obvious that with concentration, the number will be increased at a much greater ratio than will the reduction of the bulk. ”

“ A storage tank is unnecessary when there is large cooking capacity, and in most cases it is a source of trouble rather than a help. A sample should be taken as soon as the batch is drawn, and the specific gravity determined so that the proper quantity may be used to give a finished product of uniform consistency. Assuming that 500 gallons of pulp will give a normal finished batch, if the tomatoes are watery, it may require 550 gallons or more to give the same result when concentrated. ”

“ Green fruit gives a weak color, and over-ripe fruit is prone to become injured and spoil in handling. The tomato should be through the process of manufacture within twenty-four hours from the time that it is taken from the vine. Repeated experiments have shown that rapid handling of fruits and vegetables gives the best results for canning, and the tomato is no exception to the rule when used for ketchup. ”

“ In the tomato the hypoderm consists of two or three layers of cells, parts of which usually separate with the epidermis. Below these cells are the thin-walled parenchyma cells, which are approximately globular, vary considerably in size, are very loosely held together, and have many intercellular spaces. These cells constitute the mass of the pulp, and with the juice constitute 96.2 per cent of the tomato. ”

“ 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. ”

“ If it be decided to use trimmings from the peeling tables, provision must be made for extra washing, as the ordinary washer removes little more than the coarse dirt and particles, is not sufficient for unusual conditions or to remove tightly-adhering material, and, furthermore, rot must be eliminated before the tomatoes go to the peelers. The writer has never seen a group of one hundred, or any number, of peelers who will stop to trim and separate rot from peels and cores. Trimming can be done better by a few when sorting the tomatoes than at any subsequent step. ”

“ 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. ”

“ 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. ”

“ The vacuum pan is coming into use for concentrating pulp, but has been little used in making the finished ketchup. The jacketed-kettle is used by most manufacturers, though the tank and coil is being adopted by those who wish to make large batches, as it is the more economical. Agitators are no longer used, as by proper handling of the steam and automatic traps, little burning occurs on either kettles or coils. The efficiency of the open tank or kettle is increased by providing a strong exhaust or suction for the air at the back and just above the top of the kettle. ”

“ The sugar is usually added when the cooking is about one-half completed. There is an advantage in heating both the sugar and vinegar in a separate kettle and adding them while hot, as it will prevent a check to the cooking and lessen the sticking to the coils or kettle.
Salt is used in small quantity and is added near the close of the cooking process.
The use of flour or starch in any quantity for the purpose of making the body thick or heavy is properly regarded as an adulteration. This is also true of pulp from a foreign source, like pumpkin or apples. ”

“ No inspection can be made adequate if the tomatoes pile on the belt two or three layers deep, or pass at such a rate that the eyes tire and all look alike. This is a place where more belts moving slowly, and fewer persons working on each belt, will give the better results. Hand sorting is essential and far more important than in tomato canning. In the latter the defective parts are cut away, but no machine has yet been devised to make the separation complete in making pulp or ketchup. ”

“ The principle of the strong pressure is seen in using a hose without a nozzle to wash a floor and one with a nozzle and strong pressure. In the former case it does not clean, while with the latter it does and with less water. The washer just described is too vigorous for tomatoes for canning, as the treatment is too rough. If the tomatoes are soft or badly cracked, it causes considerable loss, but not of material that should be used in ketchup. The strong sprays will also cut off adherent mold and soft rot. A thoroughly good washer will do about nine-tenths of the work for the inspectors. ”

“ 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 vigor with which the washing is done is always apparent in the finished product. The poor washing usually given to tomatoes for canning, accounts in a measure for the relatively large numbers of organisms found in ketchup made from trimmings.
PULPING. After washing, the tomatoes may be reduced to a pulp in one of three ways: by running the raw tomatoes directly through a grinder and into the cyclone; by passing the tomatoes through a scalder and into the cyclone; and by turning the tomatoes into jacketed-kettles or tanks and cooking them until soft before running through the cyclone. ”