酰基稳态化花色苷的制备及其热降解特性和抗氧化活性

食品级的肉桂酸甲酯为酰基供体，运用减压酶法，催化其与矢车菊素-3-O-葡萄糖苷（C3G）发生酰化反应，具有绿色安全、高效且酰化产物单一等优点。对酰化产物进行分离，并进行热稳定性和抗氧化性等性质的测定。结果表明：酰化转化率为80%；利用半制备高效液相色谱仪对酰化后的产物进行分离纯化，纯化后的酰化C3G纯度达98.3%；经质谱分析可知，酰化后产物为矢车菊素-3-(6-肉桂酰)-葡萄糖苷（C3(6C)G）。酰基化修饰使花色苷的脂溶性、热稳定性得到了明显改善。采用1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除、2,2-氨基-二(3-乙基-苯并噻唑啉-6-磺酸)（2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid,ABTS）阳离子自由基清除、铁离子还原/抗氧化能力法（ferric reducing and antioxidant power,FRAP）、羟自由基清除体外实验测定不同浓度下C3G、C3(6C)G和VC的抗氧化能力。与相同浓度的VC相比，除了在ABTS阳离子自由基清...

Preparation of Acylated Anthocyanin and Its Thermal Degradation Properties and Antioxidant Activity

Food-grade methyl cinnamate as an acyl donor was used to enzymatically acylate cyanidin-3-O-glucoside (C3G) under reduced pressure, which has the advantages of safety, high efficiency and single acylation product. After being purified by semi-preparative high-performance liquid chromatography (SP-HPLC), the acylation product was evaluated for its thermal stability and antioxidant activity. The results showed that the acylation rate was 80%, and the purity of the purified acylated C3G was as high as 98.3%. Mass spectral analysis showed that the acylated product was cyanidin-3-(6-cinnamoyl)-glucoside (C3(6C)G). Acylation modification significantly improved the lipid solubility and thermal stability of C3G. C3G and C3(6C)G had weaker scavenging capacity against 2,2-amino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation but similar 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, ferric reducing and antioxidant power (FRAP) and hydroxyl radical scavenging capacity compared with vitamin C (VC) at the same concentration. At 200 μmol/L, the hydroxyl and DPPH radical scavenging capacity of C3(6C)G was significantly enhanced compared with C3G (P < 0.05), while there was no significant difference in ABTS radical cation scavenging or FRAP between C3G and C3(6C)G (P > 0.05), which showed that cinnamyl modification did not impair the antioxidant capacity of anthocyanins, but instead improved the scavenging capacity against hydroxyl radicals.