Center for Viticulture and Enology, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China; Key Laboratory of Viticulture and Enology, Ministry of Agriculture and Rural Affairs, Beijing 100083, China.
Center for Viticulture and Enology, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China; Key Laboratory of Viticulture and Enology, Ministry of Agriculture and Rural Affairs, Beijing 100083, China.
Food Chem. 2019 Jun 15;283:315-323. doi: 10.1016/j.foodchem.2018.12.135. Epub 2019 Jan 14.
The reaction kinetics of five primary wine anthocyanins (cyanidin-3-O-glucoside, peonidin-3-O-glucoside, delphinidin-3-O-glucoside, petunidin-3-O-glucoside, and malvidin-3-O-glucoside) and (-)-epicatechin with the presence of acetaldehyde were evaluated in model wine solutions at a range of varying temperatures (25, 35, 45, and 55 °C). The loss of anthocyanins followed first-order reaction model, while the formation of two isomers of anthocyanin ethyl-linked (-)-epicatechin was fitted to zero-order reaction model. The rate constant (k) showed that petunidin-3-O-glucoside was the most reactive anthocyanin, followed by the two 3',4'-substituted anthocyanins (peonidin-3-O-glucoside and cyanidin-3-O-glucoside), while the least reactive were another two 3',4',5'-substituted anthocyanins (malvidin-3-O-glucoside and delphindin-3-O-glucoside). The activation energies (E) indicated that the formation of ethyl-linked products from methylated anthocyanins were more sensitive to temperature than that from hydroxylated anthocyanins. Thermodynamic parameters showed a non-spontaneous and endothermic process. Besides, the evolution of the visible color of reaction solution was affected by the stability of anthocyanins and the formation of ethyl-linked products.
在一系列不同温度（25、35、45 和 55°C）的模型酒溶液中，评估了五种主要葡萄酒花色苷（矢车菊素-3-O-葡萄糖苷、芍药素-3-O-葡萄糖苷、飞燕草素-3-O-葡萄糖苷、牵牛花素-3-O-葡萄糖苷和锦葵色素-3-O-葡萄糖苷）和（-）-儿茶素与乙醛共存时的反应动力学。花色苷的损失遵循一级反应模型，而花色苷乙基连接的（-）-儿茶素的两种异构体的形成则符合零级反应模型。速率常数（k）表明，矢车菊素-3-O-葡萄糖苷是最具反应性的花色苷，其次是两种 3',4'-取代的花色苷（芍药素-3-O-葡萄糖苷和矢车菊素-3-O-葡萄糖苷），而最不具反应性的是另外两种 3',4',5'-取代的花色苷（锦葵色素-3-O-葡萄糖苷和飞燕草素-3-O-葡萄糖苷）。活化能（E）表明，甲基化花色苷形成乙基连接产物对温度的敏感性高于羟基化花色苷。热力学参数表明这是一个非自发的吸热过程。此外，反应溶液可见颜色的演变受到花色苷稳定性和乙基连接产物形成的影响。
