单宁对紫甘薯花色苷的辅色作用研究

Studies on the copigmentation effect of tannin on purple sweet potato anthocyanins

在不同温度和光照条件下研究了紫甘薯花色苷、紫甘薯花色苷单宁辅色动力学特性。结果表明,在缓冲液pH值为4.0条件下,添加0.1 mo.lL-1单宁的紫甘薯花色苷热降解活化能为43.09 kJ.mol-1,比紫甘薯花色苷高11.57%。与紫甘薯花色苷相比,同一温度下单宁紫甘薯花色苷热降解速率低,半衰期长,耐热性好。单宁紫甘薯花色苷光降解速率是紫甘薯花色苷的92.8%。表明单宁能增强花色苷对光、热的稳定性,对紫甘薯花色苷有辅色作用。

Kinetics proportion of purple sweet potato anthocyanin （PSPA）, copigmentation between PSPA and tannin at different temperature and light intension were studied in this paper. When 0. 1 mol · L^-1 tannin was added at pH4.0 buffer, the heat-degradation active energy of PSPA was 43.09 kJ· mol^-1, which was 11.57% higher than that of PSPA without tannin. Compared with PSPA without tannin, heat degradation velocity of PSPA-tannin complex was lower, heat half life longer. It suggested that PSPA- tannin complex was more heat-resistant than PSPA without tannin. Light-degrading velocity of PSPA-tannin complex was 92. 8% of that of PSPA without tannin. These results suspected that tannin could improve stabilities of PSPA to heat and light and have copigmentation effect to PSPA.