Effect of Grape Pomace on Some Biological Assays of Experimental Rats

Document Type : Original Article


Special Foods and Nutrition Department, Food Technology Research Institute, Agriculture research center, Giza, Egypt


This study is carried out to reduce the environmental impact of grape proceeding wastes through study the effect of the grape pomace (GP) utilization on some biological parameters which reflect the health status of rats fed on high fat diets. It was carried out via an experimental biological study, where adult healthy male albino rats, weighing 1855g, were fed on high-fat diets supplemented with 5, 10, and 15% of GP. The proceeding results showed that the protein amount in GP was up to 8.75%, lipids content was 7.38% and the total dietary fiber was 46.63%. K, Mg, Ca, Na, P and S were found in higher concentrations. The lipids of GP contained 85.75% unsaturated fatty acids (19.14% monounsaturated and 66.60% polyunsaturated fatty acid).The predominant fatty acid was linoleic acid (65.29%). Total phenolic (TP) compounds (expressed as mg gallic acid equivalent (GAE) per g sample) were about 50.35mg GAE/g, total flavonoids (expressed as mg rutin equivalent (RE) per g sample) were 22.25 mg RE/g and the DPPH radical scavenging activity was 51.92%. Gallic acid was the most abundant polyphenols, (9.76 mg/100g). Catechin was the most abundant flavonoid compound (52.5 mg/100g). Resveratrol as stilbenes content was 14.11 mg/100g. Supplementation of the high-fat diet with GP resulted in a significant reduction in cholesterol, triglycerides, LDL-C and vLDL-C levels of the tested rat groups. Treated rats had higher mean values of HDL-C than that fed on HFD only. The best result for estimation of specific studied parameters (AST, ALT, urea, uric acid and creatinine) revealed that the rat groups fed on the high fat diet containing 15% GP was the healthiest. It was found that a non-significant alteration in the levels of AST, ALT, uric acid and creatinine, compared with the negative control rat group was detected. Consequently, it could be concluded that GP could be considered as a source of healthy compounds that could be applied in animal feed, pharmaceutical, cosmetic or food industries.