桑葚花色苷的分离纯化及其热降解动力学研究

Purification and Thermal Degradation Kinetics of Anthocyanins from Mulberry

通过AB-8大孔树脂、乙酸乙酯萃取和Toyopearl TSK HW-40S凝胶柱层析对桑葚汁中的花色苷进行分离纯化,得到两个单一的化合物组分。经HPLC-MS鉴定这两种花色苷分别为矢车菊素-3-芸香糖苷和矢车菊素-3-葡萄糖苷。在此基础上,研究了不同纯度花色苷的降解动力学,结果表明:桑葚花色苷粗提物中所含的黄酮类化合物对花色苷的热降解有较强的保护作用,含黄酮的花色苷体系对p H值的变化更为敏感。在p H 3.5时,矢车菊素-3-芸香糖苷和矢车菊素-3-葡萄糖苷的热稳定性基本相同;在p H 4.0时,矢车菊素-3-芸香糖苷的热稳定性略好于矢车菊素-3-葡萄糖苷。

AB-8 macroporous resin, ethyl acetate extract and Toyopearl TSK HW-40S column were employed to separate and purify the anthocyanins from mulberry. Subsequently, two fractions Were obtained and each fraction con- tained a single anthocyanin. Two anthocyanins were identified as cyanidin 3-glucoside and cyanidin 3-rutinoside by HPLC-MS analysis, respectively. Moreover, degradation kinetics of anthocyanins with different purity were further investi-gated. The results indicated that flavonoids contained in the crude anthocyanins extract of mulberry had a protective effect on degradation of anthocyanins, however, the anthocyanins system which contained flavonoids was more sensitive to the change of pH value. In addition, the results also indicated that the thermal stabilities of cyanidin 3-glucoside and cyani- din 3- rutinoside were almost the same at pH 3.5, while the thermal stability of cyanidiin 3-rutinoside was a little higher than that of cyanidin 3-glucoside at pH 4.0.