Department of Food Science and Technology, University of Tennessee , Knoxville, Tennessee 37996, United States.
J Agric Food Chem. 2012 Aug 1;60(30):7526-31. doi: 10.1021/jf3021656. Epub 2012 Jul 23.
Heating is commonly used in the manufacture of dairy products, but impacts of thermal denaturation on binding between whey protein and molecules such as pigments are poorly understood. The objective of this work was to study the impacts of thermal denaturation on binding between bixin, a pigment relevant to colored cheeses, and whey proteins using several complementary techniques. Fluorescence spectroscopy data showed that heat treatment caused tryptophan in β-lactoglobulin and α-lactalbumin to be exposed to a more polar environment, but the opposite was observed for bovine serum albumin. The fluorescence quenching study indicated that the quenching of whey protein fluorescence by bixin was static quenching, and the affinity of binding with bixin was enhanced after thermal denaturation, caused by a higher extent of unordered structures, as revealed by results from circular dichroism and Fourier transform infrared spectra. β-Lactoglobulin was responsible for overall impacts of thermal denaturation on binding between bixin and whey protein isolate.
加热在乳制品制造中普遍使用，但热变性对乳清蛋白与色素等分子之间结合的影响还知之甚少。本研究旨在使用多种互补技术研究热变性对与彩色奶酪相关的类胡萝卜素色素红没药醇与乳清蛋白之间结合的影响。荧光光谱数据表明，热处理导致β-乳球蛋白和α-乳白蛋白中的色氨酸暴露于更具极性的环境中，但牛血清白蛋白则相反。荧光猝灭研究表明，红没药醇对乳清蛋白荧光的猝灭为静态猝灭，并且热变性后结合红没药醇的亲和力增强，这是由于圆二色性和傅里叶变换红外光谱的结果表明无序结构的程度更高。β-乳球蛋白是热变性对红没药醇与乳清蛋白分离物之间结合影响的主要原因。
