A study of the culinary properties of peanut oil for deep-fat frying

Abstract

It is thought that the peanut (Arachis hypogaea) originated in South America as peanuts have been found in the ancient burial graves in Peru. From South America they were carried to Arica and then to the United States with the slaves who came from Africa. It has been stated that when peanuts were placed in the hold of an old ship with the slaves, the slaves were in excellent physical condition on arrival for there was no beriberi.

The peanut is perhaps the most important oil-bearing seed that is grown and its value as a source of oil has long been recognized. The Dutch buy peanuts from many countries and bring them to Rotterdam, where they crush the, into oil and meal, and barter these products to other countries. Much of their oil was formerly imported into the United States for here the peanut as a source of oil was not realized. Until a few years ago less than 8 percent of the crop was crushed for oil. However, 40 percent of the crop was used for oil in 1940.

The “cake” or meal which is left after the oil has been expressed makes an excellent feed for cattle and is used as such to a great extent, particularly in Germany.

During the first World War there was a great demand for peanut oil and today the need is felt again. It is stated in the Peanut Journal and Nut World (21) that peanut oil imports from foreign countries in the first six months of the 1940-1941 season decreased about 17 percent from the total reached during the same period of the previous years. Today the Secretary of Agriculture has called upon the peanut farmers of the nation to greatly expand their peanut acreage for the production of oil during the coming year. The goal for 1942 is 3,400,000 acres for peanut oil and 1,600,000 acres for edible use. In 1940 only one fourth of the crop of 200,000 tons of peanuts was used for oil. From each ton of peanuts approximately 600 pounds of oil can be obtained.

Peanut oil is used in the United States mainly as an adulterant of or as a substitute for olive oil. It is so excellent in quality that most people cannot detect the difference. Peanut oil is mixed with nearly all the olive oil that comes from the United States.

Peanut oil can replace, in part at least, the approximate 10,000,000 pounds of coconut oil that until now has been imported into the country for roasting peanuts, making soap and other uses.

Since peanut production has been greatly increased for edible oil, and since so little research has been done on the culinary properties of the oil, a study of these properties seemed advisable. The primary purpose of this experiment was to study the palatability of potato chips, shoestring potatoes and French friend potatoes when fried in peanut oil as compared with those friend in cottonseed oil. The absorption of the oil by the products fried in peanut oil was compared with those fried in cottonseed oil. The changes in the two oils during repeated fryings was compared. These changes were measured by the smoking point, free acidity, and rancidity changes of the oils. Since the oils for this experiment could not be produced under experimental conditions, certain constants were measured in order to know about the qualities of the oils.

These included the iodine number, saponification number, free acidity, smoking point and the resistance of the oils to rancidity changes.