蓝莓花色苷的酶法酰化修饰及其疏水性改善研究

为了解决花色苷疏水性较差的问题，本文通过酶法对蓝莓花色苷进行酰化改性，将阿魏酸和咖啡酸接枝到花色苷分子上，并对相关产物的结构、疏水性和抗氧化活性进行了测定。结果表明，阿魏酸和咖啡酸通过酰化反应接枝到花色苷分子糖基上-OH位。阿魏酸修饰花色苷（Fe-An）和咖啡酸修饰花色苷（Ca- An）的酰化度分别为3.65%和3.71%。同时，酰化花色苷中的花青素含量从370.2 mg/g（天然蓝莓花色苷，Na-An）降低至219.2 mg/g（Fe-An）和222.18 mg/g（Ca-An）。另外，酰化改性显著提高了蓝莓花色苷的疏水性和抗氧化活性，其辛醇-水分配系数（KOW）从?0.20（Na-An）提高至0.66（Fe-An）和0.78（Ca-An），DPPH自由基清除率从66.3%（Na-An）上升至68.4%（Fe-An）和74.7%（Ca-An），β-胡萝卜素漂白抑制率从63.1%（Na-An）上升至85.5%（Fe-An）和90.3%（Ca-An）。以上结果表明，阿魏酸和咖啡酸的引入显著提高了蓝莓花色苷的疏水性和抗氧化活性，这将极大的拓展花色苷在高脂类食品中的应用。

Improving the Hydrophobicity of Blueberry Anthocyanins through Enzymatic Acylation Modification

In order to solve the problem of poor hydrophobicity of anthocyanins, in this paper, the blueberry anthocyanin was acylated with ferulic acid and caffeic acid, and the structure, hydrophobicity and antioxidant activity of related products were analysed. The FTIR and UV-Vis analysis indicated that ferulic acid and caffeic acid were grafted on the -OH of the glycosyl of the blueberry anthocyanins through acylation reaction, and the acylation degree of the anthocyanins acylated with ferulic acid (Fe-An) and caffeic acid (Ca-An) was 3.65% and 3.71%, respectively. Meanwhile, the total anthocyanidin content was decreased from 370.2 mg/g (Na-An) to 219.2 mg/g (Fe-An) and 222.18 mg/g (Ca-An), respectively. In addition, the hydrophobicity and antioxidant activity of blueberry anthocyanins were significantly improved after acylation with the two phenolic acids. The octanol-water partition coefficient (KOW) was increased from ?0.20 (Na-An) to 0.66 (Fe-An) and 0.78 (Ca-An), DPPH clearance increased from 66.3% (Na-An) to 68.4% (Fe-An) and 74.7% (Ca-An), and inhibition ratio of β-carotene bleaching increased from 63.1% (Na - An) to 85.5% (Fe-An) and 90.3% (Ca-An). The results show that the introduction of ferulic acid and caffeic acid significantly improve the hydrophobicity and antioxidant activity of blueberry anthocyanins, which will greatly expand the application of anthocyanins in high-fat foods.