不同有机酸对黑莓花色苷辅色效果的影响

摘要

Different organic acids on Copigmentation effect of blackberry anthocyanins in water system were investigated including the color stability and thermal stability.The results showed that:The activation energy (Ea) of blackberry anthocyanins were improved by malic acid,malonic acid and oxalic acid (P ＜ 0.05).Oxalic could increase the Ea by 86％ and significantly improved thermal stability.At the time of half-life,the thermal stability reduced with temperature increasing no matter organic acid was added or not.Under the conditions of 70 ℃,T1/2 values of adding malic acid,malonic acid and oxalic acid,were 22.07,21.46 and 34.15 h,respectively,all higher than that of the control group of 19.04 h.No anthocyanins derivatives were formed during the copigmentation.It indicated that non-covalent copigmentation had happened between oxalic acid and blackberry anthocyanins.%研究了不同有机酸对黑莓花色苷纯化物在水体系中的色泽稳定性及热稳定性的影响.结果表明:经苹果酸、丙二酸和草酸辅色后的黑莓花色苷活化能Ea(P ＜0.05)均得到显著提高,其中草酸显著提高黑莓花色苷的热稳定性,Ea提高86％.经苹果酸、丙二酸和草酸对黑莓花色苷辅色后T1/2显著高于对照(P＜0.05).在70、80和90℃条件下,经草酸辅色的T1/2分别为34.15、18.48和10.12 h,显著高于对照组的19.04、14.87和9.89 h.黑莓花色苷辅色后的L*值随加热温度的升高和时间的延长呈上升趋势,a*值呈下降趋势,显著高于对照组(P＜0.05).草酸、苹果酸和丙二酸可显著减小黑莓花色苷色泽的降解速率,其中草酸辅色效果最好.经草酸辅色的黑莓花色苷成分与辅色前相比,未发生变化,推测草酸与黑莓花色苷的辅色作用为分子间非共价键辅色.根据实验结果,证明草酸、苹果酸和丙二酸对黑莓花色苷具有辅色作用,有可能作为辅色剂.