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Green Tea Quality Evaluation Based on Its Catechins and Metals Composition in Combination with Chemometric Analysis
Wojciech Koch1, Wirginia Kukula-Koch2, Łukasz Komsta3
1Chair and Department of Food and Nutrition, Medical University of Lublin, 4a Chodźki Str., 20-093 Lublin, Poland. kochw@interia.pl.
Molecules (Basel, Switzerland)
|July 13, 2018
Summary
This study analyzed green tea quality by measuring catechins and metal content across various origins. Korean Jeoncha showed the best quality, with high catechin levels and safe metal concentrations.
Area of Science:
- Food Chemistry
- Analytical Chemistry
- Phytochemistry
Background:
- Green tea is a globally popular beverage, particularly in Asia.
- Green tea quality is determined by catechin content and elemental composition, impacting biological properties, quality, and safety.
Purpose of the Study:
- To evaluate catechin content, antioxidant activity, and metal concentrations in green teas from Japan, Sri Lanka, South Korea, India, and China.
- To assess the influence of these components on the overall quality and safety of different green tea types.
Main Methods:
- Utilized Liquid Chromatography-Electrospray Ionization-Quadrupole Time-of-Flight Mass Spectrometry (LC-ESI-Q-TOF-MS) for organic compounds.
- Employed atomic absorption spectrometry (flame and electrothermal) for inorganic element analysis.
- Applied chemometric methods, including Principal Component Analysis (PCA), for data interpretation.
Main Results:
- Epigallocatechin (EGC) and Epigallocatechin gallate (EGCG) were the predominant catechins, with highest concentrations found in South Korean Jeoncha and Japanese Sencha, respectively.
- Chinese and Indian green teas exhibited the highest levels of toxic heavy metals, yet remained below established safety limits.
- PCA indicated strong similarities between Japanese green teas and Korean Jeoncha.
Conclusions:
- Korean Jeoncha demonstrated superior quality based on the evaluated parameters, including high catechin content and acceptable metal levels.
- The study provides a comprehensive analysis of green tea composition, highlighting regional variations and quality indicators.
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