The Ohio State University, Dept. of Food Science and Technology, 2015 Fyffe Ct., Columbus, OH 43210-1007, United States.
Food Chem. 2019 Apr 25;278:443-451. doi: 10.1016/j.foodchem.2018.11.076. Epub 2018 Nov 14.
The impact of glycosylation on anthocyanin stability has largely been associated with sugar type, site, and size, with glycosyl stereochemistry being under-explored. Seven cyanidin-3-glycosides were isolated by HPLC, diluted in pH 1-9, mixed with bisulfite or ascorbic acid at pH 3, and stored for 8 weeks (25 °C, dark). Spectral changes, half-lives, and bleaching rates were determined. Cyanidin-3-galactoside was more reactive (susceptible to hydration and bleaching) than cyanidin-3-glucoside. The 1 → 2 disaccharides exhibited greater λ (≤16 nm), resistance to hydration, and bleaching compared to 1 → 6 disaccharides.The 1 → 6 disaccharides had similar λ (∼2 nm) to the monosaccharides but slightly improved resistance to hydration and bleaching. The tri-glycosylated anthocyanin had the greatest stability and its spectral and bleaching characteristics was intermediate to 1 → 2 and 1 → 6 disaccharides. The 1 → 2 disaccharides generally exhibited lower half-lives compared to monosaccharides; whereas, 1 → 6 disaccharides exhibited higher stability. These findings highlight the role of glycosyl assembly on anthocyanin reactivity and stability.
糖基化对花色苷稳定性的影响主要与糖的类型、位置和大小有关，而糖基立体化学的研究还很不充分。通过高效液相色谱法分离出 7 种矢车菊素-3-糖苷，将其在 pH1-9 下稀释，在 pH3 下与亚硫酸氢盐或抗坏血酸混合，并在 25°C（黑暗）下储存 8 周。测定光谱变化、半衰期和漂白率。矢车菊素-3-半乳糖苷比矢车菊素-3-葡萄糖苷更具反应性（易发生水合和漂白）。1→2 二糖苷比 1→6 二糖苷具有更大的 λ（≤16nm）、对水合和漂白的抵抗力。1→6 二糖苷与单糖具有相似的 λ（约 2nm），但对水合和漂白的抵抗力略有提高。三糖苷花色苷具有最大的稳定性，其光谱和漂白特性介于 1→2 和 1→6 二糖苷之间。1→2 二糖苷的半衰期通常比单糖短；而 1→6 二糖苷则表现出更高的稳定性。这些发现强调了糖基化组装对花色苷反应性和稳定性的作用。
