Role of green tea nanoparticles in process of tea cream formation – A new perspective

• Published in: Food chemistry Vol. 339; p. 128112
• Main Authors: Guo, Cheng, Chen, Yijie, Li, Jing, Zhan, Fuchao, Wei, Xianling, Li, Bin
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2021
• Subjects: Caffeine; Caffeine - chemistry; Calorimetry; Catechin - analogs & derivatives; Catechin - chemistry; Dynamic Light Scattering; Epigallocatechin gallate; Green tea nanoparticles; Hydrophobic and Hydrophilic Interactions; Microscopy, Electron, Transmission; Nanoparticles - chemistry; Tea - chemistry; Tea cream; Ternary aggregate; ζ-Potential; EGCG; CAF; ζ-Potential; DLS; MWCO; Epigallocatechin gallate; Green tea nanoparticles; PDI; gTNPs; FTIR; Dz; ITC; Tea cream; TEM; HPLC; Ternary aggregate; LDV; Caffeine
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2020.128112

•A ternary aggregate formed by gTNPs and EGCG-CAF complex was confirmed in tea cream.•Hydrophobic interaction dominated the formation of gTNPs/EGCG/CAF ternary aggregate.•ITC was used to examine the effect of gTNPs on the interaction between EGCG and CAF.•The physicochemical properties of gTNPs were characterized. 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.