酰基化十大功劳果花色苷的光热降解动力学分析

Analysis of the Photic and Thermal Degradation Kinetics of Acylation Anthocyanin in the Mahonia bealei Fruit

为提高十大功劳果花色苷的应用性,通过酰基化反应对其进行分子修饰,并研究光热降解动力学特征.紫外吸收光谱表明十大功劳果花色苷已经酰基化.研究表明:酰基化十大功劳果花色苷的光热降解动力学符合动力学一级反应规律,线性关系良好(R>0.95),且热降解半衰期tl/2(未酰化)<tl/2(乙酸)<tl/2(丙二酸)<tl/2(丁二酸).热降解Ea(未酰化)<Ea(乙酸)<Ea(丙二酸)<Ea(丁二酸).相对未酰化的十大功劳果花色苷,酰基化修饰后的花色苷光、热稳定性显著提高,尤其丁二酸酰化花色苷效果极显著.酰基化处理十大功劳果花色苷有利于色素在光热处理条件下的应用及保存.

In order to improve the applicability of Mahonia bealei fruit anthocyanin,its molecular modification is carried out through acylation reaction,and the photic-thermal degradation kinetics is studied.Ultraviolet absorption spectrum shows that Mahonia bealei anthocyanins have acylation.The analysis shows that the thermal degradation kinetics of acylation Mahonia bealei fruit anthocyanin conforms to the first-order reaction kinetics regularity,and good linear relationship(R>0.95),and tl/2(not acylated)<tl/2(acetic acid)<tl/2(malonic acid)<tl/2(succinic acid).The thermal degradation has the following relationships:Ea(succinic acid)>Ea(malonic acid)>Ea(acetic acid)>Ea(not acylated).Compared to unacylated Mahonia bealei anthocyanin,anthocyanins with succinic acid,malonic acid,acetic acid acylation modified,significantly improve the optical and thermal stability,especially the acylation of succinic acid.Acylation of Mahonia bealei anthocyanins help the application and preservation of the pigment in heat treatment conditions.