Ultrasonic extraction, structural characterization, and antioxidant activity of oligosaccharides from red yeast rice. Issue 1 (24th November 2021)

• Record Type: Journal Article
• Authors: Liu, Kai; Xie, Long; Gu, Huan; Luo, Jia; Li, Xiaofang
• Is Part Of: Food science & nutrition. Volume 10:Issue 1(2022)
• Page Start: 204
• Page End: 217
• Publication Date: 2021-11-24
• Subjects: oligosaccharide -- red yeast rice -- structure elucidation -- ultrasonic‐assisted extraction; Food industry and trade -- Periodicals; Food -- Periodicals; Nutrition -- Periodicals; 664
• DOI: 10.1002/fsn3.2660
• Languages: English
• ISSNs: 2048-7177

Abstract

Abstract: Red yeast rice is consumed as a medicinal food to lower blood lipids. Besides, it is used to color food, make wine, etc. In this study, water‐soluble oligosaccharides in red yeast rice were extracted by ultrasonic‐assisted extraction method. The parameters to extract oligosaccharides from red yeast rice were optimized by the Box‐Behnken design under the following optimal extraction conditions: extraction temperature, 60°C; extraction time, 97 min; and liquid/material ratio, 25 ml/g. The structure and the antioxidant activity of the new oligosaccharide were preliminarily investigated. Total carbohydrates extracted from red yeast rice with 80% ethanol–water solution (v/v) were first removed from pigments using D101 macroporous adsorption resin. The total sugar contents were then purified by DE52 resins and Sephadex G‐25 resins to obtain red yeast rice oligosaccharides, coded as RYRO1. Structural characterization experiments indicated that RYRO1 is an oligosaccharide with a weight average molecular weight of 874 Da and a theoretical degree of polymerization of 4.86. RYRO1 is composed of mannose, glucosamine, glucose, and galactose with a molar ratio of 0.248:0.019:1:0.026. The ABTS, DPPH, and hydroxyl free radical scavenging assays showed antioxidant nature of RYRO1. Abstract : A new oligosaccharide was isolated from red yeast rice. RYRO1 consists of mannose, glucosamine, glucose, and galactose. RYRO1 possesses in vitro antioxidant activity.