Optimising the extraction of tea polyphenols, (−)‐epigallocatechin gallate and theanine from summer green tea by using response surface methodology

Abstract

In this study, response surface methodology was applied to determine the optimal conditions for the extraction of tea polyphenols, EGCG and theanine from summer green tea. As results, the optimal extraction conditions were determined to be temperature 96°C, time 40 min and ratio of water to raw material 16 mL g )1 . Under these optimal conditions, the experimental values for tea polyphenols, EGCG, theanine and IC 50 for DPPH free radical scavenging activity were 133.41 ± 3.12 mg gallic acid g )1 , 30.23 ± 1.22, 3.99 ± 1.13 mg g )1 and 724.95 ± 15.12 lg mL )1 , respectively. There was no statistical difference at significant level of 0.05 between the experimental and predicted values. The results suggested that the regression models were accurate and adequate for the bioactives extraction from summer green tea.

Green tea polyphenols reduce obesity in high‐fat diet‐induced mice by modulating intestinal microbiota composition

“…Green tea was obtained locally (Ningbo, Zhejiang province), GTP was prepared according to the reported method with some modifications (Zhang et al, 2012). Briefly, 10 kg of tea powder was extracted with 160 L of distilled water at 96°C for 40 min.…”

Stop for tea? Enzyme inhibitors from tea – what good are they?

“…Thus, tea components especially catechins, theanine and caffeine might be regarded as candidate inhibitors of these diseases. However, much more animal experiments should be carried out to confirm the obtained results; in particular, dose and style of drinking tea should be carefully formulated for the special prevention purpose; much more studies should be carried out to illustrate the inhibitory mechanisms of the tea components on the enzymes, and some novel techniques with high yield or purity of the tea components might also be developed furthermore although many approaches had been attempted (Chandini et al ., ; Zhang et al ., ; Choung et al ., ). Nevertheless, tea is a well‐known healthy beverage, and why do not we stop for tea?…”

Minimising variation in aspalathin content of aqueous green rooibos extract: optimising extraction and identifying critical material attributes

“…Some flexibility can be built into the extract production process to ensure that variability in raw material quality can be accommodated, although without moving the product out of specification. The concept and application of the principles of QbD have not only been advocated for pharmaceutical product development, but also recently for the production of botanical drug products . Design of Experiments (DoE) employing experimental designs such as a central composite design (CCD) or a Box–Behnken design and multivariate statistics for the optimisation and establishment of a control space comprise the inherent elements of QbD …”

“…The concept and application of the principles of QbD have not only been advocated for pharmaceutical product development, 11 but also recently for the production of botanical drug products. 12 -15 Design of Experiments (DoE) employing experimental designs such as a central composite design (CCD) or a Box-Behnken design and multivariate statistics for the optimisation and establishment of a control space comprise the inherent elements of QbD. 16 The present study aimed to investigate the production of a high-quality green rooibos extract, representing a recovery of at least 160 g kg −1 DMY with an AC of 80 g kg −1 , using a QbD approach.…”