Manzocco Lara, Plazzotta Stella, Calligaris Sonia
Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Via Sondrio 2/A, 33100 Udine, Italy.
Foods. 2020 Dec 24;10(1):26. doi: 10.3390/foods10010026.
The capacity of UV-C light to induce glycation and modify functional properties of systems containing freeze-dried egg white proteins and carbohydrates with increasing molecular weight (i.e., glucose, maltose, trehalose and maltodextrin) was studied. Color changes induced by light exposure were taken as typical indicators of glycation. Samples were then analyzed for selected physical (critical concentration, particle size and viscosity), chemical (ovalbumin content) and technofunctional properties (gelling temperature and foaming capacity). The presence of sugars during exposure to UV-C light promoted intense browning and decreased ovalbumin content by circa 30%. Concomitantly, up to a 3-fold increase in critical concentration of the aqueous suspensions of the irradiated protein-carbohydrate powders and changes in particle size were detected. These modifications were consistent with the development of non-enzymatic browning reactions upon UV-C light irradiation. Photoinduced glycation was associated to a decrease in viscosity, a tendency to form gel at temperature lower by up to 8 °C and a better capacity of foam stabilization. The intensity of these changes seems to be affected by the nature of the carbohydrates reacting with proteins, with longer carbohydrates able to produce systems with higher foam stability capacity.
研究了紫外线C光诱导糖基化以及改变含有冻干蛋清蛋白和不同分子量碳水化合物（即葡萄糖、麦芽糖、海藻糖和麦芽糊精）体系功能特性的能力。光照引起的颜色变化被视为糖基化的典型指标。然后对样品的选定物理性质（临界浓度、粒径和粘度）、化学性质（卵清蛋白含量）和技术功能性质（凝胶化温度和发泡能力）进行分析。在紫外线C光照射期间，糖的存在促进了强烈的褐变，并使卵清蛋白含量降低了约30%。同时，检测到辐照后的蛋白质-碳水化合物粉末水悬浮液的临界浓度增加了3倍，且粒径发生了变化。这些变化与紫外线C光照射下非酶褐变反应的发生一致。光诱导糖基化与粘度降低、在低至8°C的温度下形成凝胶的趋势以及更好的泡沫稳定能力有关。这些变化的强度似乎受与蛋白质反应的碳水化合物性质的影响，较长的碳水化合物能够产生具有更高泡沫稳定能力的体系。
