The influence of temperature, heating time, and aeration upon the nutritive value of fats

Abstract

In order to determine the biological significance of the changes which occur when fats are heated to high temperatures in air, cottonseed oils were heated and aerated under several controlled conditions. In general, the data indicate that the changes induced are proportional to the severity of the conditions and that treatments more severe than those usually encountered in processing or cooking are necessary to produce detectable damage. Oils which had been subjected to prolonged aeration at 60C (16 days or more) or exposed to air in thin layers maintained at 180舑220C supplied less available energy and caused development of larger livers than untreated samples when compared in rat feeding tests. Heating in deep layers caused less damage than heating to the same temperatures in thin films, indicating that exposure to oxygen accelerates nutritional impairment. The cooking of food in fats changes condition so greatly that direct extrapolation of data obtained in tests using fat alone is not justified. Fat extracted from foods has not been found to contain harmful substances by the tests used.

Effect of Oils in Feed on the Production Performance and Egg Quality of Laying Hens

“…In general, MDA, a stable compound, is presumed to be the end product of lipid oxidation. Therefore, the MDA content in oils is used as an indicator of the oxidation level of oils [ 196 , 197 ].…”

Biological observations from feeding heated corn oil and heated peanut oil to rats

“…The current generation is being socialized to enjoy the fast-food hamburger as well as many deep-fat fried foods such as fried chicken, fish pieces, french fries, and a variety of chips (Smith et al, 1985). Investigators studying fat derived from commercial deep-fat frying operations have demonstrated either substantial adverse reactions (Johnson et al, 1957;Poling et al, 1962;Sugai et al, 1962;Yoshida et al, 1975;Meltzer et al, 1981) or moderate nutritional effects (Keane et al, 1959;Nolen et al, 1967;Poling et al, 1970;Nolen, 1973) from feeding animals diets containing fats subjected to the heat and oxidation of normal usage. The commercially used fats normally were considered to be no longer fit for human consumption, or had reached the end of their frying life.…”

Antioxidant Activity of Peptides Obtained from Porcine Myofibrillar Proteins by Protease Treatment

“…It is well-known that lipid peroxidation occurring in food products causes such deteriorations of food quality as rancid flavor, unacceptable taste, and shortening of shelf life. Consuming oxidative foods is thought to cause serious diseases such as hepatomegaly (1) or necrosis of epithelial tissues. The factors involved in these diseases are lipid peroxides and low molecular weight compounds produced during the late stage of the oxidative reaction (2).…”