The Role of Extracting Solvents in the Recovery of Polyphenols from Green Tea and Its Antiradical Activity Supported by Principal Component Analysis

Abstract

Green tea contains a variety of biologically active constituents that are widely used in the pharmaceutical and food industries. Among them, simple catechins constitute a major group of compounds that is primarily responsible for the high biologic activity of green tea extracts. Therefore, the application of optimized extraction conditions may result in obtaining high value extracts. The main purpose of the study was to compare the content of polyphenols, mainly catechins, and the antioxidant activity of green tea extracts obtained by three different extraction methods: simple maceration, ultrasound extraction and accelerated solvent extraction using six various solvent systems. The quality of the extracts was evaluated by LC-ESI-Q-TOF-MS methodologies and spectrophotometric determinations. The obtained results revealed that catechins’ extraction efficiency was identical for the three techniques studied. However, larger quantitative differences among the samples were observed when using different solvents. The total content of major catechins and gallic acid was within a very wide range of 10.2–842 mg/L. Ethyl acetate was by far the least effective extractant, regardless of the extraction technique used. After all, the solvent system composed of ethanol:water (1:1 v/v) was proven to be the best to recover catechins and to deliver extracts with the highest antiradical activity.

Effect of green tea extract, ginger essential oil and nanofibrillated cellulose reinforcements in starch films on the keeping quality of strawberries

“…Koch et al. (2020) also reported that the use of methanol as a solvent resulted in a higher yield of bioactive components from green tea compared to water as a solvent. As methanolic GTE possessed high values of TPC, TFC and antioxidant activity than water GTE, it was further used for incorporation in starch polymer for the development of active packaging films.…”

Validated HPTLC and antioxidant activities for quality control of catechin in a fermented tea (Camellia sinensis var. assamica)

“…However, pressurized liquid extraction using methanol produced better recoveries of catechin (C) and epicatechin (EC) than water, ethanol, and ethyl acetate (Piñeiro et al., 2004). This indicates that ethyl acetate usage has a limitation depending on catechins of interest along with types and conditions of extraction methods (Koch et al., 2020). However, in this research, ethyl acetate is suggested to be the best solvent for isolating the catechin‐enriched fraction from CE by partitioning technique at room temperature.…”

(−)-Epicatechin-Enriched Extract from Camellia sinensis Improves Regulation of Muscle Mass and Function: Results from a Randomized Controlled Trial

“…Green tea has well-known health benefits that have been attributed to its high content of antioxidant polyphenol catechins [33,34]. Hence, various methods for producing tea extracts with high levels of antioxidant activity and extractability have been attempted [35][36][37]. However, low bioavailability of green tea catechins limits the potential therapeutic benefits of green tea [18].…”