Key Laboratory for Deep Processing of Major Grain and Oil, Ministry of Education, Hubei Key Laboratory for Processing and Transformation of Agricultural Products, School of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, P. R. China.
School of Biological Science and Biotechnology, Minnan Normal University, Zhangzhou 363000, P. R. China.
J Agric Food Chem. 2020 Jul 15;68(28):7467-7473. doi: 10.1021/acs.jafc.0c01912. Epub 2020 Jun 30.
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 H 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.
为了使富含油脂的食品能够使用花色苷，本研究采用肉桂酸对越橘花色苷进行酰化处理，以改善其较差的脂溶性。基于傅里叶变换红外光谱（FTIR）、X 射线衍射（XRD）、X 射线光电子能谱（XPS）和氢核磁共振分析的结构分析表明，肉桂酸通过酯化反应有效地接枝到葡萄糖苷和半乳糖苷的 6-OH 和阿拉伯糖的 5-OH 上。酰化剂剂量越高，酰化程度（AD）越高，越橘花色苷的总花色苷含量（TAC）越低。An-Ci4 的 AD 值最高（6.61%），而 An-Ci3 的 TAC 值最低（50.16mg/g）。用亲脂性肉桂酸酰化后，酰化越橘花色苷的脂溶性显著提高。在乙酸乙酯和二恶烷中溶解的天然越橘花色苷溶液的颜色为透明，而在这些溶剂中溶解的酰化花色苷溶液则呈现出明显的红色。在抗氧化活性方面，酰化越橘花色苷在 2,2-二苯基-1-苦基肼（DPPH）清除能力方面表现较差，但在β-胡萝卜素漂白试验中对抑制率的表现优于天然越橘花色苷。随着 AD 值的增加，酰化花色苷的 DPPH 清除能力降低，β-胡萝卜素漂白试验中的抑制率增加。
