title: Bioconversion of Cyanidin-3-Rutinoside to Cyanidin-3-Glucoside in Black Raspberry by Crude α-L-Rhamnosidase from Aspergillus Species.
abstract: Cyanidin-3-glucoside (C3G) has been known to be more bioavailable than cyanidin-3- rutinoside (C3R), the most abundant anthocyanin in black raspberry (Rubus occidentalis). The aim of this study was to enhance the bioavailability of anthocyanins in black raspberry by cleaving L-rhamnose in C3R using crude enzyme extracts (CEEs) from Aspergillus usamii KCTC 6956, A. awamori KCTC 60380, A. niger KCCM 11724, A. oryzae KCCM 12698, and A. kawachii KCCM 32819. The enzyme activities of the CEEs were determined by a spectrophotometric method using rho-nitrophenyl-rhamnopyranoside and rho-nitrophenyl-glucopyranoside. The CEE from A. usamii had the highest α-L-rhamnosidase activity with 2.73 U/ml at 60°C, followed by those from A. awamori and A. niger. When bioconversion of C3R to C3G in black raspberry was analyzed by HPLC-DAD, the CEEs from A. usamii and A. awamori hydrolyzed 95.7% and 95.6% of C3R to C3G, respectively, after 2 h incubation. The CEEs from A. kawachii and A. oryzae did not convert C3R to C3G in black raspberry.
authors.affiliation: Department of Food and Nutrition, and Research Institute of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Taehwan
authors.initials: T
authors.lastname: Lim
authors.affiliation: Department of Food and Nutrition, and Research Institute of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Hana
authors.initials: H
authors.lastname: Jung
authors.affiliation: Department of Food and Nutrition, and Research Institute of Human Ecology, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Keum Taek
authors.initials: KT
authors.lastname: Hwang
mesh_terms: D000872:Anthocyanins / Q000378:metabolism*; D001230:Aspergillus / Q000201:enzymology*; D001711:Biotransformation; D005960:Glucosides / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000378:metabolism*; D065856:Rubus / Q000378:metabolism*; D013696:Temperature
chemical_list: D000872:Anthocyanins; D005960:Glucosides; C462279:cyanidin-3-O-beta-glucopyranoside; D006026:Glycoside Hydrolases; C022525:alpha-L-rhamnosidase; C428983:cyanidin 3-rutinoside
keywords: Anthocyanin; Aspergillus; Black raspberry; Rhamnosidase