Study on copigmentation effect and stability of flavonoids on spine grape anthocyanins

The copigmentation was studied on the spine grape anthocyanins by different flavonoids. The effects of quercetin,baicalein and rutin on the thermal stability of spine grape anthocyanins were also investigated. The results showed that the most significant copigment was quercetin(p<0.05),followed by baicalein and rutin,and the best concentration of copigment was 0.1 mmol/L~(-1). Quercetin and baicalein had the best copigmentation effects at p H2.0,while rutin at p H3.0. The degradation rate(k) of spine grape anthocyanins decreased after adding quercetin,baicalein and rutin,and the half-life(t_(1/2)) were improved(p<0.05). The activation energy(E_a)of quercetin,baicalein and rutin were 88.48,91.67 and 83.62 k J/mol,respectively,all significantly(p<0.05)higher than that of the control group which was 74.51 k J/mol. The results indicated that quercetin,baicalein and rutin could improve the thermal stability of spine grape anthocyanins.