To enable the use of anthocyanins in food with high oil content, bilberry anthocyanins were acylated with cinnamic acids to address their poor lipid solubility. Structural analyses based on Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ¹H nuclear magnetic resonance analyses indicated that cinnamic acids were efficiently grafted onto 6-OH of glucoside and galactoside and 5-OH of arabinose through an esterification reaction. The higher the dose of the acylating agent, the higher the acylation degree (AD) and the lower the total anthocyanidin content (TAC) of bilberry anthocyanins. An-Ci4 presented the highest AD value (6.61%), and An-Ci3 exhibited the lowest TAC value (50.16 mg/g). After acylating with lipophilic cinnamic acids, the lipid solubility of acylated bilberry anthocyanins significantly improved. The color of the native bilberry anthocyanin solution dissolved in ethyl acetate and dioxane was transparent. By contrast, the acylated anthocyanin solution dissolved in these solvents was unmistakably red. In terms of the antioxidant activity, acylated bilberry anthocyanins demonstrated inferior performance in 2,2-diphenyl-1-picrylhydrazyl (DPPH) clearance but a better inhibition ratio in β-carotene bleaching assay compared with native bilberry anthocyanins. As AD value increased, the DPPH clearance of acylated anthocyanins decreased and their inhibition ratio increased in β-carotene bleaching assay.

中文翻译：

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肉桂酸酰化制备脂溶性越桔花色苷及其抗氧化活性。

为了在高油含量的食品中使用花色苷，将越橘花色苷用肉桂酸酰化以解决其不良的脂溶性。基于傅立叶变换红外光谱（FTIR），X射线衍射（XRD），X射线光电子能谱（XPS）和^{1的结构分析}H核磁共振分析表明，肉桂酸通过酯化反应被有效地接枝到葡糖苷和半乳糖苷的6-OH和阿拉伯糖的5-OH上。酰化剂的剂量越高，越桔花色苷的酰化度（AD）越高，总花色苷含量（TAC）越低。An-Ci4的AD值最高（6.61％），An-Ci3的TAC值最低（50.16 mg / g）。用亲脂性肉桂酸酰化后，酰化的越桔花色苷的脂溶性显着提高。溶解在乙酸乙酯和二恶烷中的天然越桔花色苷溶液的颜色是透明的。相反，溶解在这些溶剂中的酰化花色苷溶液无疑是红色的。在抗氧化活性方面，酰化的越桔花色苷与天然越桔花色苷相比，在2,2-二苯基-1-吡啶并肼基（DPPH）清除率方面表现较差，但在β-胡萝卜素漂白测定中的抑制率更高。随着AD值的增加，在β-胡萝卜素漂白试验中，酰化花色苷的DPPH清除率降低，其抑制率增加。