Preserving Foods

Foods to be preserved should be perfectly fresh. Yeo gives four methods of preservation:

(1) Drying is the method most available for preserving peas, beans, prunes, apricots and other fruits. Milk and eggs may both be preserved by desiccation.

(2) Exclusion of air may be applied in several ways. Smoking, which coagulates the outer surface and sterilizes it, serves for preserving ham, bacon, fish, etc. Packing in sawdust, etc., or dipping in wax preserves eggs. Canning in tins or jars under steam heat is used for preserving many kinds of food, all air thus being forced out before the can or jar is hermetically sealed.

(3) Freezing and cold storage are used extensively for preserving fish, meat, jams, etc. Such foods must be cooked immediately upon thawing.

(4) Antiseptics are used very extensively in food preservation. The oldest and most widely known of these are salt, vinegar, alcohol and syrups. More recently a great variety of antiseptic chemicals have been used - benzoate of soda, salicylic acid, etc., etc. The advisability of their use, even in minute quantities, is questionable.

Concentration

Most foods can be reduced to a dry or otherwise condensed state without loss of nutritive value or danger of decomposition; and on account of the resulting economy in price and storage room may enter into the dietaries of hospitals and institutions. Sugar, oil and starch, and many cereal products, are already in a state of concentration. Powdered milk and meat, egg powder, etc., are coming more and more into use. Condensed milk has long been a useful product (see milk and milk preparations), as have dried and evaporated fruits and vegetables. All these products can be used in cookery. Their chief use as mainstays will doubtless be in cases of temporary shortage of fresh foods, due to devastating storms, "strikes" and other happenings which interrupt traffic.

Predigestion Of Food

Much is written against the use of predigested foods as a steady diet for the well. Many starchy foods on the market are partially digested by heat. The objection seems to rest on the theory that such foods give the digestive fluids and muscles of the digestive organs nothing to do, and that a sort of sluggishness is set up. It cannot be said truthfully that these claims have ever been backed up by facts. No one denies that thorough mastication is a great advantage, and with thorough mastication much of the starch is predigested in the mouth, or, after swallowing, in the fundus of the stomach. Predigested proteins are not used as staple foods, and as little is gained by very finely masticating flesh foods, the stomach has plenty of work in digesting animal proteins. If there is fat in the diet the pancreas can. never fall into a state of disuse. Hence the outcry against partially predigested breakfast foods does not seem justified on this score. It is true, however, that their absence of flavor, and the soft and pulpy character of some of them are recognized as possible drawbacks; for semi-solid and pultaceous foods are difficult to masticate, while their insipidity does not flavor a flow of digestive fluids. If adherence to these foods causes sluggish digestion and inability to deal with food in more natural condition, one would impute this not to predigestion, but to the fact that the tastelessness and the ease with which they may be bolted, are the real factors which bring about a passive state of the digestive functions.

In a diet for the ill, the dyspeptic, the convalescent, etc., there can be no possible objection to predigestion; on the contrary, it is highly desirable up to a certain extent. But just as soon as possible the patient should return to foods in the natural state, bearing in mind that a small minority of cases, even the acutely ill, thrive on food which in theory would be hazardous to say the least. Apparently hopeless cases of sepsis have seemingly been rescued by placing patients on food suited only for the healthy. Such patients must, however, have a natural appetite and be able to tolerate the food.

Adulteration Of Food

"Since the passage of the National Pure Food and Drugs Act, giving to the United States Government authority to enforce stringent laws against the adulteration and misbranding of foods which enter into interstate commerce, and the more rigid enforcement of similar state laws which regulate these matters in many of the states, a great burden has been lifted from the shoulders of the buyer. This legislation has enormously decreased the deceptions formerly practiced by some manufacturers, and since it insures that the name and description on bottle and package shall not misrepresent the contents, the buyer, if he knows what he wants, will have no difficulty in obtaining it, while the honest manufacturers and dealers (and they have without doubt always outnumbered the others) will also be protected. This matter in its various aspects is taken up in publications of the Bureau of Chemistry1 of this Department." 2 For Table of Common Adulteration of Foodstuffs, note Farmer's Bulletin No. 25, of the United States Department of Agriculture, Division of Chemistry, "Washington, D. C.

1 U. S. Dept. Agriculture Bureau of Chemistry, Bulletin 100; Year Book 1907, p. 321.

2 U. S. Dept. Agriculture, Bureau of Chemistry, Bulletin 325, p. 19.