Animal Fats

The principal animal fats and fatty foods are butter, cream, suet, lard, oleomargarine, the fat of beef, mutton, pork and bacon, bone marrow, pemmican, fish, and cod-liver oil. Fat is also a constituent of the yolk of eggs.

Butter and cream have been discussed under the heading Milk Derivatives (pp. 95-99).

Lard is hog fat separated by melting from the areolar connective tissue. Considerably over half a billion pounds are annually produced in the United States. Crude lard contains glycerides of oleic, stearic, and palmitic acids, besides a little gelatin and other substances.

"Cuisine" is a preparation of cotton-seed oil designed to replace lard and cheap cooking butter.

" Cottolene " is another substitute for cooking purposes.

Stearins are the solid residue of animal fats remaining after pressure has separated the fluid fats. They are used in making compound lard, butterine, and similar foods.

Suet is the fat which surrounds the kidneys of the ox, sheep, and other animals.

Oleomargarine

Oleomargarine was invented in 1870 by a French chemist, Mege-Mourier, who discovered that beef fat from particular portions of the bullock would melt at the same temperature with butter, and would keep longer without becoming rancid. The fresh fat is mashed in a grinding machine to free it from membrane. "The fragments fall into a tank heated with steam, which for every thousand parts of fat contains three hundred parts of water and one part of carbonate of potash and two stomachs of sheep or pigs. The temperature of the mixture is raised to 450 C." (Clark). After two hours the fat is withdrawn from the membranes, which have been digested away, and is heated still more with the addition of 2 per cent of salt. It is then cooled, pressed, and packed for market.

PLATE IX.

Beef Fat x 40.

Beef Fat x 40.

Oleomargarine x 40 Animal Fats, Magnified.

Oleomargarine x 40 Animal Fats, Magnified.

(From Bulletin No. 13, Division of Chemistry, United States Agricultural Bureau).

PHOTO BY CLIFFORD RICHARDSON.

Much discussion has arisen in regard to the wholesomeness of oleomargarine, and its sale has been regulated by act of Congress since 1886 and by many State laws. It has been declared perfectly innocuous, and the object of the legal control of its sale is mainly intended to prevent it from being fraudulently offered as butter. It certainly tastes better than poor butter.

Butterine, which has now largely replaced oleomargarine in this country, is made in a similar manner, but with a somewhat different proportion of ingredients, and some of the leaf fat of the hog is added during the manufacture.

Beef Fat, Pork, Etc

Beef, mutton, and pork fat consist principally of the glycerides of such common fatty acids as stearic, palmitic, and oleic.

The fat of good roast beef is nutritious, and a very digestible variety of fat is good bacon thinly sliced and thoroughly cooked. This form of fat is crisp and dry, and it is often digested by invalids who cannot tolerate other kinds. Ham fat and pork fat, on the other hand, are usually very indigestible - the more so when hot.