Composition And Antioxidant Ability Of Clod-pressed Grape Seed Oil And Cold-pressed Grape-seed-cake Superfine Powder

Grape seed is the main component of the grape pomace which is produced during winemaking. Grape seed contains oil and other functional ingredients, with high recycling value. In this research, the grape seeds of Cabernet Sauvignon, Meili, Ecolly and Beibinghong were taken as raw material, the cold-pressed oil and grape-seed-cake was obtained by cold pressed of grape seeds. The grape-seed-cake were ultrafine grinding to obtain the grape-seed-cake superfine powder. To provide the theoretical basis for the development of high quality grape seed oil and the utilization of grape-seed-cake superfine powder, the composition and antioxidant activity of cold-pressed grape seed oil and grape-seed-cake superfine powder were investigated. In this research, the composition of the cold-pressed grape seed oil and grape-seed-cake superfine powder were determined. Also, the antioxidants activity of extracts were estimated according to the ability of scavenging DDPH·, ABTS+·, OH·and the total antioxidant capacity as well as the ability in inhibiting oxidation of cholesterol. After the study mentioned above, the best quality cold-pressed grape seed oil was found, and obtained the difference between various varieties’ grape seed oil as well as various ability in antioxidant of grape-seed-cake superfine powder between different varieties’ grape. The main results of the research:1. The four varieties’ cold-pressed grape seed oil were in line with national standards. The most abundant fatty acid in the four varieties’ cold-pressed grape seed oil was linoleic acid, ranging between 72.77 to 77.36% of total fatty acids, the conten of unsaturated fatty acids ranging between 88.12 to 91.06% of total fatty acids, total phenolic content ranging from 61 to 100μg GAE/g. The total phenolic content decreasing order was Ecolly, Beibinghong, Meili and Cabernet Sauvignon cold-pressed seed oil respectively. All of the four varieties’ cold-pressed oil had good capacity in DPPH and ABTS radical scavenging, and the scavenging capacity enhanced by the increase of concentration of oil. The value of IC50 in scavenging DPPH· ranged from 10.19 to 13.82mg/mL; the IC50 in scavenging ABTS+· ranged from 11.62 to 19.25mg/mL; the capacity in scavenging OH· ranged from 13.18 to 27.08 U/mL, the total antioxidant capacity ranged from 1.08 to 3.68 U/mL. The cold-pressed oil of Meili possessed was the best quality compare with other varieties. Antioxidant capacity in vitro decreasing order was Ecolly> Beibinghong> Meili> Cabernet Sauvignon.2. Cold-pressed grape-seed-cake superfine powder was had powerful of antioxidants activity, total phenolic content ranging between 19.61 to 79.04 mg GAE/g, proanthocyanidins conten ranging from 27.99 to 160.43 mg OPC/g. Flavonoids were the main components of nonanthocyanin phenolics ranging from 4626.77 to 16697.72 mg/kg, followed by phenolic acids ranging from 1674.18 to 4765.80 mg/kg. The highest capacity in scavenging DPPH·, ABTS·+, OH·, and total antioxidant capacity was Cabernet Sauvignon, while Meili had the highest capacity in inhibition of the cholesterol oxidation. In conclusion: the cold-pressed grape seed oil was rich in unsaturated fatty acid, containes a certain amount of polyphenols, had a high antioxidant capacity. There has significant difference in composition and antioxidant capacity of various varieties’ grape seed oil. These results proved that there was practical meanings in studing the single variety grape seed oil in developing high quality grape seed oil.3. Among the antioxidant indicators measured in this study, there was significant correlation between the total content phenolic of cold-pressed grape seed oil and grape-seed-cake superfine powder; while there also exist high correlation between the capacity in scavenging DPPH·,ABTS·+. The cold-pressed grape-seed-cake superfine powder has abundant phenolics and efficient antioxidant capacity which make it can effectively inhibit the oxidation of cholesterol. The significant difference exists in various varieties’ grape-seed-cake superfine powder. The cold-pressed grape-seed-cake superfine powder can be regarded as a rich source of antioxidants.