title: Polyphenols extracted from black tea (Camellia sinensis) residue by hot-compressed water and their inhibitory effect on pancreatic lipase in vitro.
abstract: Polyphenols, retained in black tea wastes following the commercial production of tea beverages, represent an underutilized resource. The purpose of this study was to investigate the potential use of hot-compressed water (HCW) for the extraction of pancreatic lipase-inhibiting polyphenols from black tea residues. Black tea residues were treated with HCW at 10 °C intervals, from 100 to 200 °C. The resulting extracts were analyzed using high-performance liquid chromatography-mass spectrometry and assayed to determine their inhibitory effect on pancreatic lipase activity in vitro. Four theaflavins (TF), 5 catechins, 2 quercetin glycosides, quinic acid, gallic acid, and caffeine were identified. The total polyphenol content of extracts increased with increasing temperature but lipase inhibitors (TF, theaflavin 3-O-gallate, theaflavin 3'-O-gallate, theaflavin 3,3'-O-gallate, epigallocatechin gallate, and epicatechin gallate) decreased over 150 °C. All extracts inhibited pancreatic lipase but extracts obtained at 100 to 140 °C showed the greatest lipase inhibition (IC(50) s of 0.9 to 1.3 μg/mL), consistent with the optimal extraction of TFs and catechins except catechin by HCW between 130 and 150 °C. HCW can be used to extract pancreatic lipase-inhibiting polyphenols from black tea waste. These extracts have potential uses, as dietary supplements and medications, for the prevention and treatment of obesity.
authors.affiliation: Food Science and Technology Inst., Morinaga Milk Industry Co., Ltd., 1-83, 5-Chome, Higashihara, Zama-City, Kanagawa-Pref. 252-8583 Japan. n-yuda@morinagamilk.co.jp
authors.forename: Naoki
authors.initials: N
authors.lastname: Yuda
authors.forename: Miyuki
authors.initials: M
authors.lastname: Tanaka
authors.forename: Manabu
authors.initials: M
authors.lastname: Suzuki
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Asano
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ochi
authors.forename: Keiji
authors.initials: K
authors.lastname: Iwatsuki
mesh_terms: D044946:Biflavonoids / Q000737:chemistry; D002110:Caffeine / Q000737:chemistry; D002392:Catechin / Q000031:analogs & derivatives / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004791:Enzyme Inhibitors / Q000737:chemistry*; D005511:Food Handling; D005707:Gallic Acid / Q000737:chemistry; D006358:Hot Temperature; D020128:Inhibitory Concentration 50; D008049:Lipase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013058:Mass Spectrometry; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry*; D059808:Polyphenols / Q000737:chemistry*; D013662:Tea / Q000737:chemistry*
chemical_list: D044946:Biflavonoids; D004791:Enzyme Inhibitors; D010936:Plant Extracts; D059808:Polyphenols; D013662:Tea; C056068:theaflavin; D002110:Caffeine; D005707:Gallic Acid; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate; D008049:Lipase