芥子酸对含壳聚糖的模型饮料中花色苷的保护作用

Protective Effect of Sinapic Acid on Anthocyanins in Chitosan-Containing Model Beverages

花色苷可作为饮料等食品体系中的天然着色剂,但其易受到食品中抗坏血酸的影响而降解,在饮料中加入壳聚糖可起到增稠的作用,但会对花色苷稳定性造成影响。探讨了不同质量浓度的壳聚糖对模型饮料体系中花色苷稳定性的影响,分析了芥子酸的添加对壳聚糖存在时花色苷稳定性的改善作用。利用加速储藏实验和降解动力学方法对不同体系中黑米花色苷稳定性进行分析,并借助分子动力学模拟分析芥子酸改善壳聚糖体系中黑米花色苷稳定性的作用机制。结果表明,在7 d加速储藏实验中,单一的壳聚糖会导致花色苷颜色稳定性降低。芥子酸能显著提高含壳聚糖的模型饮料中黑米花色苷的颜色稳定性和含量保留率。降解动力学分析显示,在壳聚糖质量浓度为5 mg/mL时,加入芥子酸能使壳聚糖实验组花色苷半衰期t 1/2提高2.3倍,并使其降解速率常数K减小0.1523 d^(-1)。分子动力学模拟结果显示,游离芥子酸的存在,能促进更多的花色苷分子靠近壳聚糖-芥子酸复合物,并形成更稳定的结合。在含壳聚糖的模型饮料中加入芥子酸可实现对花色苷的保护作用,希望为酚酸的应用和含功能性壳聚糖的模型饮料的研究优化提供一定的理论依据。

Anthocyanin can be used as a natural colorant in food systems such as beverages,but it is susceptible to degradation by ascorbic acid in foods.Chitosan can be added to beverages for thickening and stabilization,but it can have an effect on the stability of anthocyanin.The effect of different concentrations of chitosan on the stability of anthocyanin in a model beverage system was investigated,and the improvement effect of sinapic acid addition on stability of anthocyanin in the presence of chitosan was analysed.The stability of black rice anthocyanin in different systems was analyzed by accelerated storage experiments and degradation kinetic methods,and the mechanism of action of sinapic acid in improving the stability of black rice anthocyanin in chitosan systems was analyzed by molecular dynamics simulations.The results showed that a single chitosan led to a decrease in the color stability of anthocyanin in the 7 d accelerated experiment.Sinapic acid significantly improved the color stability and content retention of black rice anthocyanin in chitosan-containing model beverages.Degradation kinetic analysis showed that the addition of sinapic acid in the chitosan experimental group at a chitosan mass concentration of 5 mg/mL increased the half-life t 1/2 of the anthocyanin by 2.3 fold and reduced its degradation rate constant K by 0.1523 d^(-1).Molecular dynamics simulation results showed that the presence of free sinapic acid promoted more anthocyanin molecules to approach the chitosan-sinapic acid complex and form a more stable binding.Therefore,the addition of sinapic acid to model beverages containing chitosan could achieve a protective effect on anthocyanins,hoping to provide some theoretical basis for the application of phenolic acid and the optimization of functional chitosan model beverages in the futture.