RECOVERY OF ANTIOXIDANTS FROM GRAPE SEEDS AND ITS APPLICATION IN FRIED FOOD

摘要

The efficiencies of organic solvents and the conditions for extraction of phenolics from grape seeds were investigated. Two selected organic solvents; aqueous ethanol and acetone were studied at various concentrations from 0 to 100 percent and the extractions were conducted under room temperature or 50 degree for 3-12 hours. Results showed that under degree for 6 hours the best recovery yield of 14.9 percent was obtained with 50 percent (v/v) ethanol. Under this condition, the extract consisted of 0.33 (gram/gram grape seed) total phenol. The EC measured by the DPPH method and reducing power were 214.6 microgram/millimeter and 2.38, respectively which implied a high antioxidant activity of the extract. When considering the cost of operation and the safety concerns associated with solvent residue in the product, aqueous ethanol was a more appropriate solvent than aqueous acetone despite no significant difference in the recovery yield. The effect of the extract on retarding oxidative rancidity of fried pork products was compared with 2 commercial additives; BHT and gallic acid. At the concentration of 1.6 (gram/gram product) the extract was in retarding rancidity efficiency to BHT but lower than gallic acid.