Biological and Chemical Studies on Commercial Frying Oils

Abstract

Hydrogenated cottonseed oil heated in a commercial deep-fat fryer under actual production conditions for as long as 24 days had no deleterious effects on rats when fed at levels as high as 20% of the diet. Hydrogenated cottonseed oil heated in a commercial deep-fat fryer under actual production conditions for as long as 24 days had a higher available caloric value than the unheated control oil as measured by the caloric restriction technique as well as by the rat growth method. The increase in available caloric value of the commercially heated hydrogenated cottonseed oil may be associated with the finding that heating under these conditions apparently causes unsaturation of the fat. A highly significant positive correlation was found to exist between the nutritive value of the fat, as measured by the caloric restriction technique, and the total non-conjugated double bonds present in the fat. Fats which have been heated and oxidized under laboratory conditions yield a lower growth rate in rats than the unheated oils but exhibit no apparent symptoms of toxicity (i.e., diarrhea, rough hair coat, etc.) when tested using nutritionally adequate diets.