Effect of ultrasound on antioxidant activity of raspberry dry red wine

Sonication is recognised as a potential technique for food processing. The effect of sonication on the antioxidant activities of raspberry dry red wine was studied. Based on the DPPH free radical scavenging activity after sonication of the wine samples,the effect of ultrasonic power,ultrasonic time and ultrasonic temperature on antioxidant activity of the wine were investigated.The results showed that the optimum conditions by single- factor experiment and orthogonal experiment were 150 W of ultrasonic power,15 min of ultrasound exposure time and 50℃of ultrasound bath temperature.After the sonication of optimum conditions,DPPH free radical scavenging activity of sonicated wine was 79.16%.Compared to the untreated wine,the growth rate of concerntration of total phenolic,the DPPH free radical scavenging activity,hydroxyl free radical scavenging activity and reducing power were 13.70%,21.11%,22.64% and 21.78%,respectively. Results showed that there was significant improvement on antioxidant activity of raspberry dry red wine.