Effect of Dietary Rhodobacter capsulatus on Cholesterol Concentration and Fatty Acid Composition in Japanese Quail (Coturnix japonica) Egg

Abstract

The aim of this study was to investigate the possible hypocholesterolemic effects of Rhodobacter capsulatus on cholesterol and triglycerides concentrations in serum, egg-yolk, and fatty acid composition in egg-yolk of quails. A total of 60, 10-week-old laying Japanese quails (Coturnix japonica) were randomly assigned into 3 treatment groups (20 quails/group), and fed diets supplemented with 0 (control), 0.02, and 0.04% R. capsulatus for 6 weeks. Eggs and blood from each quail were collected at the end of the 6-week feeding period for chemical analysis. The cholesterol fractions in egg-yolk and serum were measured by enzymatic assay, and the fatty acid composition in egg-yolk was determined by gas chromatography. The results revealed that the supplementation of 0.04% dietary R. capsulatus reduced (P<0.05) cholesterol and triglycerides concentrations in serum and in egg-yolk. High-density lipoprotein cholesterol was increased, and low-density lipoprotein cholesterol and the atherogenic index were decreased (P<0.05) by dietary R. capsulatus. Hepatic cholesterol was also reduced (P<0.05) by 0.04% R. capsulatus. Yolk color was improved (P<0.05) by 0.04% R. capsulatus supplemented diet. The concentrations of monounsaturated fatty acids and polyunsaturated fatty acids (PUFA) were increased (P<0.05) in egg-yolk of the quails fed the 0.04% R. capsulatus supplemented diet than the control diet. The ratio of PUFA to saturated fatty acids in egg-yolk was improved (P<0.05) by 0.04% R. capsulatus supplemented diet. Therefore, the supplementation of dietary R. capsulatus may be a feasible means of producing quail eggs with lower cholesterol and higher PUFA content for health conscious consumers.

Keywords

• cholesterol
• egg-yolk
• fatty acid composition
• japanese quail
• rhodobacter capsulatus