Effects of Exogenous Compounds on Stability and Antioxidant Activity of Anthocyanins from Blackberry juice

The effects of 3, 4-dihydroxybenzoic acid, gallic acid, caffeic acid, ferulic acid, tannic acid, rutin, baicalein and tea polyphenols on the stability and antioxidant activity in vitro of anthocyanins from blackberry juice were studied in this paper. Results showed that the caffeic acid, 3, 4-dihydroxybenzoic acid, tea polyphenols, tannic acid and gallic acid had significant copigmentation effects on the blackberry anthocyanins. At the concentration of 0.1 mmol/L, the copigments had better effects on blackberry juice anthocyanins. For rutin, the best concentration was 0.4 mmol/L. All eight kinds of materials in test enhanced the thermal stability of blackberry juice anthocyanins to some extent. In particular, gallic acid, ferulic acid and caffeic acid showed obvious effects on the thermal stability (p<0.05) with a higher half-life time that was increased by 6.06, 2.07 and 1.39 times, respectively. Furthermore, the light stability, DPPH radical scavenging capacity and the total reducing power of blackberry juice anthocyanins were significantly improved by 3, 4-dihydroxybenzoic acid, ferulic acid and rutin. But the gallic acid and tannic acid showed decreased copigmentation effects on the light stability of blackberry juice anthocyanins. It was concluded that caffeic acid, ferulic acid, baicalein and rutin were best choices for copigmentation effects of blackberry juice anthocyanins.