College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Environment Correlative Dietology (Huazhong Agricultural University), Ministry of Education, China; College of Food and Biology Science and Technology, Wuhan Institute of Design and Sciences, Wuhan 430205, China.
College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Environment Correlative Dietology (Huazhong Agricultural University), Ministry of Education, China.
Food Chem. 2021 Mar 1;339:128112. doi: 10.1016/j.foodchem.2020.128112. Epub 2020 Sep 17.
Green tea nanoparticles (gTNPs) are considered as the precursors of tea cream, while the role of gTNPs in the process of tea cream formation remains obscure. This study indicated that gTNPs could be coated with epigallocatechin gallate (EGCG)-caffeine (CAF) complexes to form a ternary aggregate participating in tea cream formation. First, the ζ-potentials of gTNPs and EGCG-CAF complexes were adjusted by charge screening. Then, gTNPs were introduced into EGCG + CAF mixture solutions under different ζ-potential conditions to examine their effect on turbidity, particle size and components of mixture solutions. Finally, isothermal titration calorimetry (ITC) was applied to investigate the influence of gTNPs on the thermal effects of the interaction between EGCG and CAF. Our results reveal that hydrophobic interaction exceeded electrostatic repulsion to dominate the interaction between gTNPs and EGCG-CAF complexes at the low ζ-potential condition, thus forming the gTNPs/EGCG/CAF ternary aggregate.
绿茶纳米粒子（gTNPs）被认为是茶乳酪的前体，而 gTNPs 在茶乳酪形成过程中的作用尚不清楚。本研究表明，gTNPs 可以与表没食子儿茶素没食子酸酯（EGCG）-咖啡因（CAF）复合物结合形成参与茶乳酪形成的三元聚集体。首先，通过电荷屏蔽来调整 gTNPs 和 EGCG-CAF 复合物的 ζ 电位。然后，在不同 ζ 电位条件下将 gTNPs 引入 EGCG+CAF 混合溶液中，以考察它们对浊度、粒径和混合物溶液成分的影响。最后，应用等温滴定量热法（ITC）研究 gTNPs 对 EGCG 和 CAF 相互作用热效应的影响。结果表明，在低 ζ 电位条件下，疏水相互作用超过静电排斥作用，主导 gTNPs 与 EGCG-CAF 复合物之间的相互作用，从而形成 gTNPs/EGCG/CAF 三元聚集体。
