Optimisation of green tea polysaccharides by ultrasound-assisted extraction and theirin vitroantidiabetic activities

In-vitro antidiabetic activities, chemical compositions, antioxidant activities, and toxicity of black tea polysaccharides as a potential source of dietary ingredients

“…The latter two were acidic heteropolysaccharide. These results are similar to those in previous studies, showing that tea polysaccharides have arabinogalactan structures (Chen et al, 2009;Scoparo et al, 2016;Karadag et al, 2019).…”

Ultrafiltration isolation, physicochemical characterization, and antidiabetic activities analysis of polysaccharides from green tea, oolong tea, and black tea

“…The chemical constituents of tea include polyphenols, polysaccharides, amino acids, alkaloids, volatile oils, vitamins, and so on (Pastoriza et al., 2017). Tea polysaccharide (TPS), as one of the main components of tea extract, has many beneficial biological activities, including antioxidation (Karadag et al., 2019), antidiabetic (Lin et al., 2019), anticancer (Nie, Xie, Zhou, & Cao, 2007), antiatherogenic effects (Zhou et al., 2007), and immunomodulatory activity (Monobe, Ema, Kato, & Maeda‐Yamamoto, 2008; Scoparo et al., 2013).…”

Advances in the Utilization of Tea Polysaccharides: Preparation, Physicochemical Properties, and Health Benefits

“…Karadag et al, used UAE to extract low-grade green tea polysaccharides (GTPSs) and then reported the optimal extraction parameters through response surface optimization as follows: 80 °C for extraction temperature, 60 min for extraction time, 400 W for ultrasonic power, and 22 mL/g for liquid–solid ratio. Under these conditions, the yield of GTPS was 4.65%, which was higher than that of the hot water extraction method (1.83%) without ultrasound [ 25 ]. In addition, they also found that the Mw of GTPS obtained with ultrasonic-assisted extraction was lower, which may have been due to the partial degradation of TPS caused by the ultrasonic process.…”

“…Pre-extraction with 95% ethanol at 40 • C for 2 h, repeated three times; a water bath extraction at 60 • C for 2 h, repeated 3 times [14] Fuan Baicha and Pingyang Tezaocha Extraction at 80 • C for 1.5 h, repeated two times [15] Fuzhuan tea 2 h extraction time, 1:20 solid-liquid ratio, and 95 • C extraction temperature; repeated three times [10] White tea 8 min extraction time, 54.1 • C extraction temperature, 12.48 L/g material-water ratio; repeated four times [16] Green tea Heating in a water bath at 90 • C for 2 h with continuous stirring [17] Green tea Pre-extraction with absolute ethanol for 24 h and extraction with deionized water at 60 • C for 90 min [18] Chin brick tea 80% ethanol pretreatment and continuous stirring with distilled water (1:20, w/v) at 90 • C for 2 h [19] Liupao tea 80% ethanol pretreatment for 24 h and extraction with deionized water at 70 • C for 2 h; repeated three times [20] Tea flowers Extraction at 90 • C for 1 h (2 times) [21] Green tea 80% ethanol pretreatment at 70 • C for 1.5 h, extraction with ethanol at 40 • C for 3 h [22] Green tea Pretreatment with two times volume of 95% ethanol at 50 • C for 4 h, 1:8 solid-liquid ratio, and extraction with stirring at 50 • C for 120 min [23] Green tea Pretreatment with 95% alcohol (1:5, w/v) for 2 h, extraction in hot water (1:10, w/v) at 80 • C; repeated 3 times for 1 h each time [24] Green tea 95% ethanol (1:6, w/v) pretreatment at 60 • C for 4 h and extraction with distilled water (1:10, w/v) at 80 • C for 4 h; repeated 3 times [25] Keemun black tea Pretreatment with 95% ethanol (1:6, w/v) at 80 • C for 2 h and immersed in distilled water (1:10, w/v) at 80 • C for 4 h; repeated four times [26] Ultrasonic-assisted extraction Low-grade green tea 80 • C extraction temperature, 60 min extraction time, 400 W ultrasonic power, and 22 mL:g liquid-solid ratio [27] Coarse tea Pretreatment in an ultrasonic bath (50 • C, 200 W) for 30 min followed by extraction in a water bath for 90 min; repeated three times [23] Green tea flowers Ultrasonic power (25 • C, 100, 150, 200, 250, and 300 W) extraction for 5 min; repeated 2 times [21] Yellow tea 95% ethanol pretreatment for 6 h, 90 • C water bath extraction for 55 min (repeated twice), and sonication (20 kHz, 500 W) for 55 min [21] Table 1. Cont.…”