Department of Nutrition and Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
Department of Nutrition and Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; Xinghua Industrial Research Centre for Food Science and Human Health, China Agricultural University, Xinghua, Jiangsu 225700, China; Beijing Laboratory of Food Quality and Safety, China Agricultural University, Beijing 100083, China.
Food Chem. 2022 May 30;377:131749. doi: 10.1016/j.foodchem.2021.131749. Epub 2021 Dec 1.
The Maillard reaction products (MRPs) between polydextrose (PDX), a popular polysaccharide in formula powder, and β-lactoglobulin (β-LG), a major whey protein, were studied in aggregation degree, structure, hydrophobic, antigenic and antioxidant activity changes of β-LG. Incubation of PDX and β-LG (60 ℃, 79% relative humidity) for up to 72 h yielded MRPs with increases in furosine, UV absorbance, fluorescence intensity and loss of free amino groups. High molecular weight β-LG-PDX MRPs were observed by SDS-PAGE. Circular dichroism spectroscopy revealed negligible change in β-LG secondary structure. Changes in the tertiary structure of β-LG were detected by tryptophan fluorescence spectroscopy consistent with an increase in surface hydrophobicity of heated β-LG-PDX. Antigenicity reduction of β-LG in β-LG-PDX reached its peak when heated for 24 h. After heating for 72 h, DPPH radical-scavenging activity of β-LG-PDX increased by 7.4-fold, and the ferric reducing antioxidant power reached 61.1 µmol ascorbic acid/g protein.
聚葡萄糖（PDX）是配方粉中常用的多糖，β-乳球蛋白（β-LG）是乳清中的主要蛋白质，本文研究了 PDX 与β-LG 之间的美拉德反应产物（MRPs）对β-LG 的聚集程度、结构、疏水性、抗原性和抗氧化活性的影响。PDX 和β-LG（60℃、79%相对湿度）孵育长达 72 h 后，MRPs 的糠氨酸、紫外吸光度、荧光强度和游离氨基含量增加。SDS-PAGE 观察到高分子量的β-LG-PDX MRPs。圆二色性光谱显示β-LG 二级结构几乎没有变化。色氨酸荧光光谱检测到β-LG 三级结构的变化，与加热的β-LG-PDX 表面疏水性增加一致。β-LG-PDX 中β-LG 的抗原性降低在加热 24 h 时达到峰值。加热 72 h 后，β-LG-PDX 的 DPPH 自由基清除活性增加了 7.4 倍，铁还原抗氧化能力达到 61.1 μmol 抗坏血酸/g 蛋白。
