Mohamed Rania, Xie Jizhou, Wei Fang, Luo Liyong, Luo Wei, Zeng Liang
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, College of Food Science, Southwest University, Chongqing 400715, China.
Department of Food Science and Technology, Faculty of Agriculture, University of Khartoum, Shambat 13314, Sudan.
Foods. 2025 Feb 5;14(3):508. doi: 10.3390/foods14030508.
The astringency of tea, predominantly attributed to epigallocatechin gallate (EGCG), plays a crucial role in shaping its overall quality, and plant-based proteins are gaining popularity as a preferred alternative to milk-based proteins for enhancing the flavor profile of tea. This study investigated the impact of extraction temperature on date palm pollen (DPP) protein quality and tea astringency, comparing temperatures of 30 °C and 80 °C. Results indicated that higher extraction temperatures yield more protein and improve the thermal and surface properties of DPP. The molecular interaction between DPP and EGCG was investigated in an aqueous solution, and spectroscopic analyses (FTIR, UV, and CD) revealed that EGCG interactions at a 1:1 molar ratio induced structural changes in α-helix and β-sheet content in secondary structures in DPP, particularly at 80 °C, which strengthened and enhanced the hydrophobic interactions and hydrogen bonds between DPP molecules as EGCG concentration increased. A sensory evaluation using quantitative descriptive analysis (QDA) confirmed a significant reduction in astringency in DPP-tea polyphenol solutions extracted at 80 °C. This research highlights the potential of DPP as a functional ingredient in the food industry, creating a protein-polyphenol complex that reduces tea's astringency while maintaining its unique flavor profile, thus offering a novel approach to enhance tea beverages.
茶的涩味主要归因于表没食子儿茶素没食子酸酯（EGCG），它在塑造茶的整体品质方面起着关键作用，并且植物性蛋白质作为替代乳基蛋白质以增强茶风味的首选替代品正越来越受欢迎。本研究调查了提取温度对枣椰花粉（DPP）蛋白质质量和茶涩味的影响，比较了30℃和80℃的温度。结果表明，较高的提取温度能产生更多蛋白质，并改善DPP的热性能和表面性能。在水溶液中研究了DPP与EGCG之间的分子相互作用，光谱分析（傅里叶变换红外光谱、紫外光谱和圆二色光谱）表明，1:1摩尔比的EGCG相互作用会导致DPP二级结构中α-螺旋和β-折叠含量发生结构变化，特别是在80℃时，随着EGCG浓度增加，这种变化会加强并增强DPP分子之间的疏水相互作用和氢键。使用定量描述分析（QDA）进行的感官评价证实，在80℃提取的DPP-茶多酚溶液中的涩味显著降低。这项研究突出了DPP作为食品工业中功能性成分的潜力，它能形成一种蛋白质-多酚复合物，在保持茶独特风味的同时降低茶的涩味，从而为增强茶饮料提供了一种新方法。
