title: Effect of different drying methods on chemical composition and bioactivity of tea polysaccharides.
abstract: Four polysaccharides (TPS-F, TPS-V, TPS-S and TPS-M) were obtained from tea (Camellia sinensis) leaves by freeze-drying, vacuum-drying, spray-drying and microwave-vacuum drying, respectively. Their chemical composition and biological properties were comparatively studied. The results showed these TPS were similar in IR, UV absorption and distribution of molecular weight. However, they showed significant differences (P<0.05) in yields of crude polysaccharides and contents of protein and total polyphenols. Furthermore, morphological analysis showed their surface differed from each other in size and shape when viewed by SEM, from which surface of TPS-F was rough and porous, surface of TPS-S was evenly particles, and surfaces of the other two were similar to anomalistic bricks. In addition, the bioactivity of them was also evaluated. It was found TPS-F exhibited relatively better ability on metal chelating and superoxide radicals scavenging assays than others, and TPS-V exhibited higher ability on α-glycosidase and α-amylase inhibition assays than others with inhibitory percentages of 82.75% and 92.8%.
authors.affiliation: Institute of Food Engineering, College of Life & Environment Science, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, PR China.
authors.forename: Yuanfeng
authors.initials: Y
authors.lastname: Wang
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Liu
authors.forename: Jianglei
authors.initials: J
authors.lastname: Huo
authors.forename: Xintong
authors.initials: X
authors.lastname: Zhaoa
authors.forename: Tingtong
authors.initials: T
authors.lastname: Zhao
authors.forename: Jian
authors.initials: J
authors.lastname: Zheng
authors.forename: Jian
authors.initials: J
authors.lastname: Ren
authors.forename: Xinlin
authors.initials: X
authors.lastname: Wei
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D005609:Free Radicals / Q000037:antagonists & inhibitors; D065089:Glycoside Hydrolase Inhibitors; D007502:Iron Chelating Agents / Q000737:chemistry / Q000494:pharmacology; D008970:Molecular Weight; D009005:Monosaccharides / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry* / Q000494:pharmacology / Q000648:ultrastructure; D013481:Superoxides / Q000037:antagonists & inhibitors; D013662:Tea / Q000737:chemistry*; D000516:alpha-Amylases / Q000037:antagonists & inhibitors
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D065089:Glycoside Hydrolase Inhibitors; D007502:Iron Chelating Agents; D009005:Monosaccharides; D011134:Polysaccharides; D013662:Tea; D013481:Superoxides; D000516:alpha-Amylases
keywords: Bioactivity; Drying methods; Tea polysaccharides