Differential behaviors of tea catechins under thermal processing: Formation of non-enzymatic oligomers
| Autor: | Yue Zhao, Fang-Yuan Fan, Yue-Rong Liang, Ying Nie, Meng Shi, Jian-Hui Ye |
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| Rok vydání: | 2016 |
| Předmět: |
Hot Temperature
Tea Hydrolysis Dimer Catechin 04 agricultural and veterinary sciences General Medicine Pyrogallol Condensation reaction 040401 food science Analytical Chemistry chemistry.chemical_compound 0404 agricultural biotechnology Drug Stability chemistry Browning Moiety Organic chemistry Epimer Oxidation-Reduction Food Science |
| Zdroj: | Food Chemistry. 196:347-354 |
| ISSN: | 0308-8146 |
| Popis: | 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 °C to 90 °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 O2 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. |
| Databáze: | OpenAIRE |
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