“SOAKED” VEGETABLES
Peas, Beans, and Corn
There is really no chemical test for this class of foods. Certain helpful directions given in Bul. 65, p. 54, of the Bureau of Chem., will assist in identifying such goods. All or nearly all of the green color of peas and beans is destroyed by the process of “soaking.” They have the appearance of the well-matured product, and are firm and mealy with well-formed cotyledons. The process of soaking starts the growth of the caulicle of the pea. The kernel of corn is plump and hard and does not have the milky consistency of the immatured product. The characteristic succulence of the green pea, bean, and corn is absent in the soaked product.
Alum in Pickles
This is sometimes added to the pickling solution to produce hardness and crispness.
Burn to ash a sample of the pickles, and, if they are free from copper, fuse in a platinum dish with sodium carbonate. Extract with boiling water, and after filtering add ammonium chlorid solution. If alum is present, a flocculent precipitate will form.
Examination of the Can or Box in which Vegetables are Sealed
Generally when the ends of a can are convex, instead of plane or concave, it is spoiled. In the souring of canned sweet corn, it is exceptional that the ends are forced outward.
Strike the can and the spoiled cans will give a dull sound while the good ones will give a distinct tone. Some practice will be necessary to use this test.
One can judge of the amount of tin dissolved by the corrosion of the inside of the can.
Reject cans that show much rust around the cap on the inside of the head.
If more than one hole is found soldered in the cap, reject the can. Cans of salmon are the only exception that has come to the author’s notice. A second hole, in general, indicates that decomposition had set in and the can had been punctured and resealed.
CHAPTER VI
FRUITS AND FRUIT PRODUCTS
Salicylic acid, benzoic acid, and saccharin are used to preserve fruits. The last is also added as a sweetener instead of sugar. Many fruit products lose their color with age, and to give them a lasting color they are treated with a coal-tar dye, cochineal, acid magenta, or caramel.
A very small per cent of the jams and jellies sold are strictly pure. These cheap products are made up principally of apple juice and commercial glucose; artificial essences are added to imitate the real flavor.
In cheap jellies made of apple juice and glucose syrup, a “coagulator” is used; usually sulfuric acid and alum, also citric and tartaric acids may be used for this purpose.
Starch, gelatin, and agar are used as gelatinizing agents.
Fruits put up in tin cans may dissolve the heavy metals as tin, zinc, lead, and even arsenic.