Autoxidation of Fish Oil Blended with Rice Bran Oil.

Effects of rice bran oil on the oxidative and flavor stability of fish oil were investigated by the gas liquid chromatography-head space method. When fish oil blending with different ratio of rice bran oils was oxidized at room temperature in the dark, volatile compounds produced during autoxidation was measured by gas liquid chromatography. The amounts of volatile compounds were decreased with increased the ratio of blended rice bran oil as well as peroxide value. The level of propanal and acrolein which gave unpleasant flavor was also decreased with increased the ratio of blended rice bran oil. Especially, the level of propanal and acrolein and peroxide value were remarkably decreased when blending more than 75% of rice bran oil. Blending of rice bran oil improved the oxidative and flavor stabilities of fish oil.

Adverse effects of excessive leucine intake depend on dietary protein intake: a transcriptomic analysis to identify useful biomarkers.

The present study was conducted to identify reliable gene biomarkers for the adverse effects of excessive leucine (Leu) in Sprague-Dawley rats by DNA microarray. It has long been known that the adverse effects of excessive amino acid intake depend on dietary protein levels. Male rats were divided into 12 groups (n=6) and fed for 1 wk a diet containing low (6%), moderate (12%) or high (40%) protein. Different levels of Leu (0, 2, 4, and 8%) were added to the diets. Consumption of diets containing more than 4% Leu in 6% protein resulted in growth retardation and reduced liver weight, whereas the administration of the same dose of Leu with 12% or 40% protein did not affect them. By a process of systematic data extraction, 6 candidate gene markers were identified. The liver gene expression data obtained from another experiment with 0, 2, 3, 4, and 8% Leu in a low-protein diet was used to examine the validity of these biomarker candidates with receiver operating characteristic (ROC) curve analysis. All of AUC values of the biomarker candidates were more than 0.700, suggesting the effectiveness of the marker candidates as the indices of Leu excess. The cut-off value for the ROC curve of the gene-marker panel, which was obtained by multiple regression analysis of gene markers, indicated that Leu levels higher than 3% have adverse effects. In conclusion, the gene-marker panel suggested that for male rats dietary Leu supplementation of 2% is the NOAEL dose in low-protein (6%) diets.