Influence of ultrafiltration on antioxidants and total antioxidant activity in blood orange juice

The influence of ultrafiltration on antioxidants and the total antioxidant activity (TAA) in blood orange juice using the tubular polyvinilydenfluoride (PVDF) membrane was studied in the paper. The results indicated that about 85% of both ascorbic acid (Vc) and anthocyanins content remained during ultrafiltration of blood orange juice. Retention of the other antioxidants such as hydroxycinnamic acids and flavonoids, except for querecetin, were more than 90%. Compared with the fresh blood orange juice, a loss of 23% of TAA in the pasteurized juice was observed, while a loss of 10% in ultrafiltered juice, which was mainly attributed to the loss of ascorbic acid and anthocyanins content.