The objective of this study was the assessment of total polyphenolic content and antioxidant activity in strawberry and blackcurrant juices with addition of pectins in comparison to clear juices. Samples were storage at 20°C without light. During 4 months storage the decrease in anthocyanins and polyphenols content was observed in both juices as well as radical scavenging activity was lower than for control samples. The composition of these juices were determined by HPLC and radical scavenging properties were measured by EPR using stable 1,1-diphenyl-2-picrylhydrazyl (DPPH•) radical. After preparation of blackcurrant juices antioxidant activity values were similar to samples with addition of pectins and control. antioxidant activity was 3,48 and 3,41 mM Troloxu/100 ml respectively. After 4 months antioxidant activity were 3,29 and 3,01 mM Troloxu/100 ml respectively. It was shown that anthocyanins are stabilizing by pectin addition.
strawberry, blackcurrant, juices, anthocyanins, antioxidant activity, EPR, free radical