Wen Kun, Zhang Qiyun, Xie Jing, Xue Bin, Li Xiaohui, Bian Xiaojun, Sun Tao
College of Food Science & Technology, Shanghai Ocean University, Shanghai 201306, China.
Foods. 2024 Sep 6;13(17):2832. doi: 10.3390/foods13172832.
As a protein extracted from soybeans, soy protein isolate (SPI) may undergo the Maillard reaction (MR) with co-existing saccharides during the processing of soy-containing foods, potentially altering its structural and functional properties. This work aimed to investigate the effect of mono- and polysaccharides on the structure and functional properties of SPI during MR. The study found that compared to oat β-glucan, the reaction rate between SPI and D-galactose was faster, leading to a higher degree of glycosylation in the SPI-galactose conjugate. D-galactose and oat β-glucan showed different influences on the secondary structure of SPI and the microenvironment of its hydrophobic amino acids. These structural variations subsequently impact a variety of the properties of the SPI conjugates. The SPI-galactose conjugate exhibited superior solubility, surface hydrophobicity, and viscosity. Meanwhile, the SPI-galactose conjugate possessed better emulsifying stability, capability to produce foam, and stability of foam than the SPI-β-glucan conjugate. Interestingly, the SPI-β-glucan conjugate, despite its lower viscosity, showed stronger hypoglycemic activity, potentially due to the inherent activity of oat β-glucan. The SPI-galactose conjugate exhibited superior antioxidant properties due to its higher content of hydroxyl groups on its molecules. These results showed that the type of saccharides had significant influences on the SPI during MR.
作为一种从大豆中提取的蛋白质，大豆分离蛋白（SPI）在含大豆食品的加工过程中可能会与共存的糖类发生美拉德反应（MR），从而可能改变其结构和功能特性。这项工作旨在研究单糖和多糖在美拉德反应过程中对SPI结构和功能特性的影响。研究发现，与燕麦β-葡聚糖相比，SPI与D-半乳糖之间的反应速率更快，导致SPI-半乳糖缀合物中的糖基化程度更高。D-半乳糖和燕麦β-葡聚糖对SPI的二级结构及其疏水氨基酸的微环境有不同的影响。这些结构变化随后会影响SPI缀合物的多种性质。SPI-半乳糖缀合物表现出优异的溶解性、表面疏水性和粘度。同时，SPI-半乳糖缀合物比SPI-β-葡聚糖缀合物具有更好的乳化稳定性、产生泡沫的能力和泡沫稳定性。有趣的是，SPI-β-葡聚糖缀合物尽管粘度较低，但显示出较强的降血糖活性，这可能归因于燕麦β-葡聚糖的固有活性。SPI-半乳糖缀合物由于其分子上较高的羟基含量而表现出优异的抗氧化性能。这些结果表明，糖类的类型在美拉德反应过程中对SPI有显著影响。
