Extraction of caffeine and catechins using microwave-assisted and ultrasonic extraction from green tea leaves: an optimization study by the IV-optimal design

Abstract

In this research, optimal conditions for extraction of caffeine and polyphenols were established from Iranian green tea leaves. In the first step, caffeine was extracted with efficacy about 86% versed to 4.5% of EGC + EGCG. The EGCG + EGC was extracted from partially decaffeinated green tea leaves through microwave-assisted extraction (MAE) and ultrasound-assisted extraction (USE) with efficiency levels of 95 and 85%, respectively. The best results for the MAE process were obtained with 7.8 min and three number of extraction cycles and for the USE process were as followed: time 57 min, temperature 65 °C, and the number of extraction cycles 3. The total phenol content values at the best conditions of MAE and the USE processes were 125 ± 5 and 96 ± 6 mg gallic acid/g DW. The 50% inhibition (IC) on 1,1-diphenyl-2-picrylhydrazyl (DPPH) were 56 and 66 mg/g of phenol for the MAE and USE processes.

Active packaging for Salmon stored at refrigerator with Polypropylene nanocomposites containing 4A zeolite, ZnO nanoparticles, and green tea extract

“…Extraction was performed via the microwave method described by (Ghasemzadeh‐mohammadi et al., 2017). This method involved preparation of dried green tea leaves followed by extraction using clevenger.…”

Environmentally Friendly Techniques and Their Comparison in the Extraction of Natural Antioxidants from Green Tea, Rosemary, Clove, and Oregano

“…A comparison between MAE and ultrasound was made regarding the extraction of total polyphenols and their antioxidant activity, where MAE was found to be more efficient with 125 ± 5 mg gallic acid/g dry weight and 56 mg/g of phenol of 2,2-diphenyl-1-picrylhydrazyl free radical assay (DPPH) inhibition 50%, while the ultrasound extract presented 96 ± 6 mg gallic acid/g dry weight of total polyphenols and 66 mg/g of phenol in the inhibition of DPPH [ 76 ].…”

Extraction of Catechins from Aegle marmelos Fruit Pulp: Statistical Optimization Using Response Surface Methodology and Artificial Neural Networks

“…Tea catechins are often used in a range of neutraceuticals, medications, and cosmetics to either lengthen product shelf life or enhance human health [10]. It has been proven that caffeine and polyphenols can be extracted from Iranian green tea leaves [11]. Catechins in Camellia sinensis leaves were extracted using an effective microwave-assisted extraction (MAE) method that utilized green deep eutectic solvents [12].…”