Effects of γ-Irradiated Fats on Plasma Lipid Concentrations and Hepatic Cholesterol Metabolism in Rats

Abstract

Currently, there is a growing need for food irradiation that is effective in food preservation and quality improvement. Accordingly, this study was designed to observe the effects of γ-irradiated dietary fat on plasma lipid concentrations and hepatic cholesterol metabolism in rats. Male rats were fed 5-kGy-γ-irradiated beef tallow (γBT), corn oil (γCO), perilla oil (γPO), and nonirradiated fats (BT, CO, and PO) for 6 weeks. The γ-irradiated fat feeding did not affect the plasma lipid concentrations. However, the hepatic cholesterol content was significantly higher in the rats fed γ-CO as compared with the rats fed nonirradiated CO (40.0 vs. 28.2 mg/g liver). The hepatic HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase activities were not significantly different between the controls and the γ-irradiated fat fed groups. However, the hepatic ACAT (acyl-CoA:cholesterol acyltransferase) activity was significantly lower in the γPO group as compared with its control group (138.2 vs. 404.5 pmol min^–1 mg^–1). Among the nonirradiated groups, the ACAT activities of the CO and PO groups were higher than that of the BT group. The amounts of coprostanone, cholesterol, and total fecal neutral sterol were significantly higher in the γPO group as compared with the other groups. These results indicate that although slight changes in the lipid metabolism were observed as a result of 5-kGy-γ-irradiated fat feeding, they were relative to the fat type and had no harmful consequences.

Oil in a Commercial Standard Diet Needs Its Product Specifications

“…Kim et al 10) studied the effects of girradiated dietary fat on plasma lipid concentrations and found that although slight changes in lipid metabolism were observed, no harmful consequences were observed. However, Lee et al 11) reported that g -irradiation (5 kGy) greatly increased oxidation of soybean oil; amounting to 10% wt/vol solvent mixture of benzene/methanol (4:1 vol/vol) from 0 to 125.75 mEq/kg of POV.…”