A. W. Bitting

“ 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. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ 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 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. ”

“ 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. ”

“ When the cork was drawn, the organisms could grow and cause spoilage, and this is a much more potent factor than the entrance of germs from without. 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 examination. ”

“ Tomato gelatin was used as a medium and cultures were made in petri dishes.
There were 17 plates on which no organisms developed, indicating that the ketchup was sterile. Of the 60 plates having organisms, 54 had molds, 22 of these having molds alone; 21 plates had yeast-like organisms, 3 plates having these only; 29 plates had bacteria, 4 having bacteria alone. Sometimes a plate would have only one form of organism, but more often there was a mixture present. Of 15 plates having only one form of organism, 3 had yeast alone, 2 bacteria alone, and 10 had mold alone. ”

“ In the tests 0.1, 0.2, 0.3, 0.4, 0.5, and 1 cc, respectively, of the extract was added to 10 cc of tomato bouillon. One set was inoculated with the mold and another set with the yeast. In the case of the mold, no growth occurred with the allspice and cloves; the celery checked the growth materially, there being no indication of mold until the sixth day. Normally a fairly strong growth occurs in twenty-four hours. In the solution containing 0.3 cc there was only one small colony in thirteen days, and no further development. ”

“ Some were kept in a warm temperature and in strong light, others in a comparatively cool place and in the original shipping cases, in order to duplicate the conditions in the warehouse and grocery store. There has been no spoilage after ten months other than that resulting from four or five cork leaks and neck cracks. 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 preservative. ”

“ Yeasts and molds are the predominating organisms, and, as the ketchup is acid and also contains sugar, and these organisms are found on tomatoes in the field, their predominance in the ketchup is explained. ”

“ Of the 77 bottles of ketchup from which the inoculations were made, 41 were without and 36 with preservative, and of the 17 sterile ketchups, 8 contained sodium benzoate and 9 were without preservative.
A considerable part of the experimental ketchup proved not to be sterile. The organisms present were of the class which require oxygen for their growth and therefore they had only been arrested in their activity. No growth could take place so long as [22] the air was excluded and therefore no spoilage could occur. ”

“ 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 ”

“ Some perform certain details well and are negligent in others. In some, large amounts of money are [9] spent on equipment to improve a particular point considered advantageous by the trade, while other details essential to the making of a good-keeping ketchup are disregarded. A statement of the best practice as observed at a number of factories, together with some facts obtained from experiments, will be given. ”

“ CULTURES FROM KETCHUP PRESERVED WITH SODIUM BENZOATE.
[29]
DEVELOPMENT.
In developing, the mold forms a white felt-like mass, covering the medium on which it is growing; then as development proceeds, it changes to bluish-green, and finally to a darker, duller color. The change in color is accompanied by a change in structure, the surface becoming powdery in appearance, a slight current of air being sufficient to dislodge a cloud of fine dust. This fine dust is formed of small, spherical bodies, the spores or conidia (from the Greek meaning dust) . ”

“ 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. ”

“ An enlarged cell will often contain two or three septa, thus forming cells that are not larger than disks. In cultures from which the air was excluded from the start, no development took place. In test-tube cultures sealed with paraffin after twenty-four hours, the mold developed on the surface of the gelatin, forming a felted white mass, but no conidia nor carpospores were formed.
GROWTH IN KETCHUP.
The form of Penicillium which was used in the experiments was isolated from ketchup in which it grew luxuriantly. ”

“ In the 15-gram solution growth was retarded four days, and most of that which did develop remained submerged, the mold growing normally on the surface. With 20 grams the growth was five days slower than the normal in starting, and after that there was only a slight development. In the 25-gram solution, the growth started at the same time as when 20 grams were employed, but remained stationary, while with the 30-gram solution, no development occurred. ”

“ The “new process” is a success in keeping ketchup, as no preservative is mentioned. The price was 20 cents.
No. 112.—Another bottle of the same brand of ketchup; examined in April, 1908; presumably manufactured in 1907; one-twelfth of 1 per cent of sodium benzoate declared on label; a bright red; guaranteed to be from fresh ripe tomatoes and uncolored. The microscope showed no dyeing of the tissues, few fungi, and no extraneous matter. The price was 20 cents.
No. 17.—Opened September 28, 1907; age unknown; a pint bottle; sodium benzoate declared on supplemental label, no amount being stated ”

“ Of the 104 bottles there were 66 without preservative, according to the labels, 46 of which spoiled. Of the 20 which did not spoil, 2 formed crystals of benzoic acid on the covers of glass dishes [21] during evaporation. Of the 39 which, according to the labels, contained sodium benzoate, 15 spoiled. The bottles of unspoiled ketchup after remaining in the laboratory for about a month were placed in the incubator at 95° F. for three weeks, and were then taken out, and have been left in the laboratory since. ”

“ After 1840 they came into general use in the Eastern States, but it was later than this before tomatoes were used freely in the Western States, many persons having the impression that, since they belonged to the nightshade family, they must be unwholesome. ”