Differential behaviors of tea catechins under thermal processing: Formation of non-enzymatic oligomers

作者：Fan, Fang-Yuan; Shi, Meng; Nie, Ying; Zhao, Yue; Ye, Jian-Hui^*; Liang, Yue-Rong

来源：Food Chemistry, 2016, 196: 347-354.

DOI：10.1016/j.foodchem.2015.09.056

• Catechins
• Steric configuration
• Thermostability
• Dimer
• Low O-2

Tea catechins as a member of flavan-3-ols subclass with the same skeleton may behave differentially. This study investigated the chemical conversions of 8 catechins under heat treatment with the involvement of epimerization, hydrolysis and oxidation/condensation reactions. Three reactions were enhanced as temperature increased from 30 degrees C to 90 degrees C. The epimerization of non-gallated catechins was favored by epi-configuration but hindered by pyrogallol moiety, and the hydrolysis reaction of gallated catechins was facilitated by pyrogallol moiety. Epicatechin and epigallocatechin had the lowest thermostabilities due to epimerization and oxidation/condensation reactions respectively. Sufficient O-2 was not a precondition for the occurrence of chemical conversions of catechins under heat treatment. Non-enzymatic oligomerization occurred to epi type catechins and catechin under heat treatment, and dehydrodicatechins A were mainly responsible for the browning of epicatechin and catechin solutions. The evidence of generation of catechin oligomers provides a novel way to explain sensory change of tea and relevant products during thermal processing.

• 出版日期2016-4-1
• 单位浙江大学