Nutritional evaluation of some heated oils

Abstract

Summary Soybean oil, cottonseed oil, and lard were heated in vacuo for either 70 and/or 100 min. at 610°F. and were fed to male and female rats at a level of 15% in the diet over a complete life span. Nutritional indices such as growth, including food efficiency and digestibility of the fats, reproduction and lactation, longevity, and tissue cholesterol and total lipid were measured. No evidence of impaired nutrition or harmfulness was observed in any group except in those fed the more highly polymerized soybean oil, where a decrease in iodine value of 10% and a 100% increase in viscosity was associated with a slight depression in growth and an interference with reproductive performance in the female animal. This interference with the reproductive process was alleviated by supplementation with α‐tocopherol. There was no evidence of increased tumor incidence in the groups ingesting the heated oils. Digestibility of the heated soybean and cottonseed oils was only slightly reduced.