Structural Characteristics of Crude Polysaccharides from 12 Selected Chinese Teas, and Their Antioxidant and Anti-Diabetic Activities

Abstract

Twelve representative edible Chinese teas (Camellia sinensis L.) from six categories (dark tea, black tea, oolong tea, white tea, yellow tea, and green tea) were selected in this study. Tea polysaccharides (TPs) were extracted with hot water, and their structural properties and biological activities, mainly antioxidant and anti-diabetic activities, were systematically evaluated. Results revealed that the extraction yields of TPs ranged from 1.81% to 6.38%, and Pu-erh tea polysaccharides had the highest extraction yield (6.38 ± 0.28%). The chemical compositions, molecular weight, and compositional monosaccharides of TPs varied among the six categories of tea. It appeared that all TPs were protein-bound acid heteropolysaccharides, and all TPs exhibited obvious antioxidant and anti-diabetic (e.g., α-glucosidase inhibitory and antiglycation) activities. Particularly, Pu-erh tea polysaccharides also contained the highest total phenolic and protein contents, and also exhibited the best antioxidant and anti-diabetic activities. Moreover, for the structural-function relationship, the heat map analysis found that total phenolic and protein contents in TPs were positively correlated with their antioxidant and anti-diabetic activities, indicating that the presence of phenolic compounds and proteins in the TPs might be the main contributors to their bioactivities. The conclusion from this study can help understand the structural-function relationship of crude tea polysaccharides.

Instant Dark Tea Alleviates Hyperlipidaemia in High-Fat Diet-Fed Rat: From Molecular Evidence to Redox Balance and Beyond

“…As the polyphenols have poor bioavailability, polysaccharides could act as a nature carrier (40). A study recent showed that the polyphenols could be the major contributor to the functionality of polysaccharides (41). Gallic acid (GA) is a primary polyphenol in dark tea, and it is known to have antihyperlipidemic effect (9).…”

Effect and synergy of different exogenous additives on gel properties of the mixed shrimp surimi (Antarctic krill and white shrimp)

“…5a), the main bands of CK were noticed at 3291 cm −1 (O–H stretch) and Amide B at 2929 cm −1 (C–H bond and O–H stretch). In addition, Amide I, II and III were noticed at 1657 cm −1 (vibration of C=O stretching), 1452 cm −1 (vibration of N–H stretch and C–N deformation) and 1237 cm −1 (C–N stretching vibration and N–H deformation), respectively (Guo et al., 2021). When different exogenous additives were added to mixed shrimp surimi preparations, the broad peak of amide A was slightly changed, implying hydrogen bonds were increased between mixed shrimp surimi and exogenous additives, which may be related to the part of the molecule involved in gel formation.…”

A Review on the Extraction, Bioactivity, and Application of Tea Polysaccharides

“…The TPSs exhibited significant antioxidant and anti-diabetic (α-glucosidase inhibition and anticoagulant) activities. Particularly, Pu’er TPS had good anti-diabetic activity [ 66 ]. Wang et al found that TPSs (at high concentrations) can improve the vascular system and reduce the lipid content in diabetic patients [ 31 ].…”

“…Moreover, their hypoglycemic activities were concentration-dependent [ 70 ]. Guo et al evaluated the anti-diabetic activity of TPSs extracted from 12 representative edible Chinese teas ( Camellia sinensis L.) and showed that black TPSs have stronger α-glucosidase inhibitory and anti-diabetic activities than the other selected tea polysaccharides [ 66 ]. Luo et al isolated polysaccharides from guava leaves (GLPs) and showed that GLPs can significantly reduce fasting glucose, total cholesterol, total triglycerides, glycated serum protein, creatinine, and malondialdehyde in Streptozotocin-induced diabetic mice [ 71 ].…”