Optimized green extraction conditions of matcha green tea (Camellia sinensis) using central composite design for maximal polyphenol and antioxidant contents

Abstract

Response surface methodology (RSM) was employed to optimize the extraction conditions of phenolic and antioxidant compounds from matcha green tea (Camellia sinensis) using central composite design (CCD). The desirability function was used to find the optimum extraction conditions. The highest polyphenol and antioxidant content yield were reached at a temperature of 80 °C, an extraction time of 20 min, a liquid-to-solid ratio of 100 mL/g, and a desirability value of 0.948. The experimental values for total phenolics under the optimum extraction conditions were 317.62 ± 3.45 mg GAE/g and 29.21 ± 0.38 mg RE/g for the total flavonoids. The antioxidant activity (AA) was evaluated using 2,2 diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), which showed radical scavenging activities at 88.28 ± 0.14% and 90.02 ± 0.14%, respectively. The high performance liquid chromatography (HPLC) analysis at the optimum condition revealed 14 compounds. Among the analyzed compounds, matcha green tea extract (MGTE) had the highest content of epigallocatechin gallate (EGCG) with 95.48 mg/g, followed by epicatechin gallate (ECG) at 74.48 mg/g, and catechin at 28.94 mg/g. The results suggested that the optimized parameters of heat-assisted extraction provide an ideal green extraction method for the extraction of the high polyphenol and antioxidant content in matcha green tea.

Subcritical Water Extraction of Phenolic Compounds from Vaccinium Dunalianum Wight Leaves and Their Antioxidant and Tyrosinase Inhibitory Activities in Vitro

“…However, a much higher liquid‐solid ratio will increase the diffusion distance to the internal tissues, and the saturation limit of solvents may be reached as the liquid‐solid ratio approaches a certain value. This can lead to the extraction of phenolic compounds almost completely and subsequently reduced the driving force [33,34] . Therefore, a much higher liquid‐solid ratio will not only waste solvents but also make the subsequent concentration work more difficult.…”

“…This can lead to the extraction of phenolic compounds almost completely and subsequently reduced the driving force. [33,34] Therefore, a much higher liquidsolid ratio will not only waste solvents but also make the subsequent concentration work more difficult. As a result, the optimum liquid-solid ratio for this experiment was determined to be 35 : 1.…”

In Vitro Investigation of Antioxidant and Antidiabetic Properties of Phenolic-Rich Extract from Stingless Bee Honey (Heterotrigona itama)

“…HPLC analysis of phenolic composition in PRE was conducted using Agilent 1200 series HPLC (Agilent, Stevens Creek Blvd, Santa Clara, CA, USA) with a C18 column (4.6 x 150 mm), and ultraviolet (UV) visible detector (Agilent Technologies, Santa Clara, CA) (16), with minor modification. The samples were dissolved with water and passed through a 0.45 μm nylon syringe filter.…”

Selective Electrochemical Detection of Catechin Compounds in Herbal Medicines

“…One of the most used methods is based on the complexation with AlCl 3 and the result is given in quercetin or rutin equivalent per gram of plant extract. [9][10][11][12] Nevertheless, when analyzing the different types of flavonoids, we face the following problem: catechol moiety (3′, 4′-dihydroxy group of B ring) of the flavan-3-ol (catechins) does not complex in neutral or acidic solution with metals, hence this colorimetric method cannot detect catechins. 9,13 To determine catechins, another colorimetric method is used that quantifies all flavonoid classes, including flavan-3-ol (catechins group), but requires more expensive reagents, is performed in basic media, and is more time-consuming because contains more steps.…”