Polysaccharides in Selenium-Enriched Tea: Extraction Performance under Innovative Technologies and Antioxidant Activities

Abstract

Pulsed electric fields (PEF) and ultrasonic-assisted extraction (UE) were applied to improve the extraction performance of selenium-enriched tea polysaccharides (Se−TPSs) in mild conditions. Two combined extraction processes were investigated: (1) PEF strength at 10 kV/cm followed by conventional extraction (CE) at 50 °C for 60 min and (2) PEF+UE (PEF strength at 10 kV/cm followed by UE at 400 W for 60 min). The optimal extraction yields, and energy consumption rates were obtained at 36.86% and 41.53% and 78.78 kJ/mg and 133.91 kJ/mg, respectively. The Se−TPSs were analyzed and characterized by GPC, UV, and FT-IR, which evidenced the structural stability of the Se−TPSs during the extraction processes. It was found that PEF and UE could reduce the particle size diameter of the Se−TPS extract, as well as the proportion of uronic acid. Moreover, PEF could increase the selenium content in the Se−TPS extract by 160.14% due to a lower extraction temperature compared to conventional extraction. The antioxidant activities of the Se−TPSs in vitro were investigated using OH, O2−, and ABTS+ scavenging experiments, as well as a total antioxidant ability evaluation. It was found that the antioxidant activity of the Se−TPSs obtained using PEF2+CE2 was relatively high due to the potential synergistic effect between the selenium and polysaccharides. Based on these results, we speculate that PEF2+CE2 was the best extraction process for the Se−TPSs. Furthermore, this research indicates the application of selenium-enriched tea for functional food production.

Polysaccharide from Ziyang Selenium-Enriched Green Tea Prevents Obesity and Promotes Adipose Thermogenesis via Modulating the Gut Microbiota

“…Furthermore, the monosaccharide constituents of Se-GTP were measured via a validated high-performance liquid chromatograph−ultraviolet analysis technology established anteriorly. 21 By using the method, 10 monosaccharides were parted within 19 min (Figure 1E). The typical chromatographic diagram of Se-GTP samples is displayed in Figure 1F.…”

“…Se-GTP was extracted according to the methods in other studies after appropriate optimization. , In brief, the crushed Ziyang Se-enriched green tea was defatted by adding ethyl alcohol (1:10, m/V) after stirring for 12 h. Water-soluble extracts were extracted from defatted tea powder three times with water at 90 °C for an hour each time, and the supernatant was collected and concentrated. Then, the concentrate was mixed with ethyl alcohol and the polysaccharide was precipitated at 4 °C for 12 h. After that, the collected precipitate was fully dissolved in water and consumingly dialyzed for 48 h against distilled water (cutoff Mw 10,000 Da) to get rid of flavonoids or polyphenols.…”

Preparation, Properties and Application in Electrospinning of Tremella Polysaccharide–Protein Complex

“…Determination of total antioxidant capacity [ 16 ]: Take 2.5 mL phosphate buffer (pH = 6.6, 0.2 mol/L), 2.5 mL 1% potassium ferricyanide solution, fully mixed in the colorimetric tube, add 1 mL sample solution, mix well, 50 °C water bath for 20 min, add 2.5 mL 10% trichloroacetic acid, mix well, 3000 r/min, 10 min, centrifuge 2 mL supernatant, add 2 mL 1% ferric chloride solution, 2 mL distilled water, react for 30 min, measure the absorbance at 700 nm.…”

Advances in extraction and purification of citrus flavonoids

“…Ultrasonic‐assisted extraction has the characteristics of high extraction efficiency, short extraction time (generally 20–60 min), low extraction temperature, wide adaptability, convenient for rapid detection with analytical instruments, and significant comprehensive economic benefits. Additionally, ultrasound‐assisted extraction can be combined with other methods such as pulsed electric fields to further improve the extraction performance in mild conditions (Gao et al., 2022).…”