State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University , Lihu Road 1800, Wuxi, Jiangsu 214122, China.
J Agric Food Chem. 2014 May 21;62(20):4677-84. doi: 10.1021/jf405157x. Epub 2014 May 7.
Polyphenols normally have strong binding affinity with proteins, which may lead to protein precipitation. Glycosylation of protein via Maillard reaction in mild condition may inhibit the precipitation. This study prepared nanocomplexes of epigallocatechin-3-gallate (EGCG) and protein, and their stability against environmental stress was investigated. Subsequently, these findings were correlated with the interactions between EGCG and casein. Results showed that glycosylated casein displayed strong encapsulating and retaining capacity to EGCG, and no obvious aggregation or fusion appeared in the concentration range of 0.25-5.00 mg/mL during storage. The in vitro release demonstrated that casein, especially glycosylated casein, could effectively protect EGCG from degradation in alkaline pH and displayed a slow and sustained release in intestinal fluid, which may be attributed to the inhibiting effects of casein binding on the motion freedom of EGCG. Fluorescence quenching spectra demonstrated that the steric hindrance induced by dextran could inhibit the interaction between casein and EGCG. These findings demonstrated that glycosylated casein could be used as a promising and effective nanocarrier for EGCG.
多酚通常与蛋白质具有很强的结合亲和力，这可能导致蛋白质沉淀。通过美拉德反应在温和条件下对蛋白质进行糖化可以抑制沉淀。本研究制备了表没食子儿茶素没食子酸酯（EGCG）和蛋白质的纳米复合物，并研究了它们对环境应激的稳定性。随后，将这些发现与 EGCG 与酪蛋白之间的相互作用相关联。结果表明，糖化酪蛋白对 EGCG 具有很强的包封和保留能力，在储存过程中浓度范围为 0.25-5.00mg/mL 时没有明显的聚集或融合现象。体外释放结果表明，酪蛋白，特别是糖化酪蛋白，能够在碱性 pH 值下有效保护 EGCG 免受降解，并在肠液中呈现缓慢而持续的释放，这可能归因于酪蛋白结合对 EGCG 运动自由度的抑制作用。荧光猝灭光谱表明，葡聚糖诱导的空间位阻可以抑制酪蛋白和 EGCG 之间的相互作用。这些发现表明，糖化酪蛋白可用作 EGCG 的一种有前途且有效的纳米载体。
