Model Studies on the Reaction Products Formed at Roasting Temperatures from either Catechin or Tea Powder in the Presence of Glucose
| Autor: | Zisheng Han, Chun-Yin Qin, Zongde Jiang, Xiaochun Wan, Chi-Tang Ho, Mingchun Wen, Liang Zhang, Guoping Lai |
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| Rok vydání: | 2021 |
| Předmět: |
Tea
Temperature food and beverages Catechin General Chemistry Gallate Theanine Mass spectrometry complex mixtures Adduct chemistry.chemical_compound Glucose chemistry Tandem Mass Spectrometry heterocyclic compounds sense organs Gallic acid Powders General Agricultural and Biological Sciences Isomerization Roasting Nuclear chemistry Chromatography Liquid |
| Zdroj: | Journal of agricultural and food chemistry. 69(38) |
| ISSN: | 1520-5118 |
| Popis: | During tea processing, roasting significantly affects the transformation pathway of catechins. When (-)-epigallocatechin gallate (EGCG) and glucose were roasted at different pH values, the degree of degradation and isomerization of EGCG was the lowest at pH 7 and the highest at pH 8. Thirty-five products were found in the model reaction of EGCG and glucose under high temperatures, of which four EGCG-glucose adducts were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and nuclear magnetic resonance (NMR). In addition, catechins, gallic acid, and theanine in tea with added glucose were significantly reduced during roasting. The contents of four EGCG-glucose adducts were increased significantly at 150 °C after 30 min and dropped gradually after 60 min. Therefore, based on the present study, EGCG could form crosslinks with glucose under high temperatures in a short time, which provides insight for tea processing and synthesis of catechin-sugar adducts. |
| Databáze: | OpenAIRE |
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