Bradshaw M P, Prenzler P D, Scollary G R
National Wine and Grape Industry Centre, Locked Bag 588, Wagga Wagga, 2678, Australia.
J Agric Food Chem. 2001 Feb;49(2):934-9. doi: 10.1021/jf000782f.
The ability of ascorbic acid to induce browning of (+)-catechin in a model wine system has been studied. A significant increase in absorbance at 440 nm was observed over 14 days when ascorbic acid was incubated at 45 degrees C with (+)-catechin in a model wine base. The onset of browning was delayed for about 2 days, although the length of the lag period was dependent on the amount of molecular oxygen in the headspace of the reaction system. The lag period was not observed when a preoxidized solution of ascorbic acid was used, suggesting that a product of ascorbic acid oxidation is responsible for the onset of browning. Hydrogen peroxide, when added directly to (+)-catechin in the model system, was not capable of producing the same degree of browning as that generated by ascorbic acid. Liquid chromotography evidence is presented to show that different reaction products are produced by ascorbic acid and hydrogen peroxide.
已对在模拟葡萄酒体系中抗坏血酸诱导（+）-儿茶素褐变的能力进行了研究。当抗坏血酸在45℃下与模拟葡萄酒基质中的（+）-儿茶素一起孵育时，在14天内观察到440nm处的吸光度显著增加。褐变的开始延迟了约2天，尽管延迟期的长度取决于反应体系顶空中分子氧的量。当使用抗坏血酸的预氧化溶液时未观察到延迟期，这表明抗坏血酸氧化产物是褐变开始的原因。当将过氧化氢直接添加到模拟体系中的（+）-儿茶素时，它不能产生与抗坏血酸产生的相同程度的褐变。液相色谱证据表明，抗坏血酸和过氧化氢产生了不同的反应产物。
