Production of Xyloligosaccharides from Rice Straw by Microwave-assisted Enzymatic Hydrolysis and Evaluation of Their Prebiotic Properties

Abstract

Rice straw (RS) is a by-product from rice production process. It is rich in cellulose, hemicellulose and lignin. RS hemicellulose mainly composes of arabinoxylan (AX). This research aimed to investigate the potential of microwave-pretreatment in AX extraction from RS and substrate to produce xylooligosaccharides (XOS) via enzymatic hydrolysis. The extractive-free RS was pretreated by microwave process at 160°C for 5-15 min, then the AX was extracted with 4% sodium hydroxide. The total sugar and reducing sugar content of AX exhibited that increasing microwave-pretreatment time increased the yield of AX. The highest AX content was found at 160°C for 10 min as 7.73%, reducing sugar content of 11.89 mg/g, and total sugar of 165.85 mg/g. The crude AX obtained by microwave-pretreatment was then used as a substrate for XOS production by two commercial xylanases of Pentopan mono BG (BG) and Ultraflo Max (UM), at the enzyme concentration of 50-300 U/g AX (50°C, pH 6.0) for 24 h.The reducing sugar content and sugar profiles were monitored by DNS assay,and thin layer chromatography (TLC) which revealed that BG 50 U/g at 12 h andUM 50 U/g at 24 h showed the promising reducing sugar of 16.4 and 25.44 mg/g,respectively. The composition of XOS derived from RS (RS-XOS) prepared by BGwas xylobiose (X2), xylotriose (X3), xylotretraose (X4), and xylopentaose (X5)while by UM was xylobiose (X2), xylotriose (X3) and xylotretraose (X5). Moreover,XOS produced by BG contained very low amount of xylose (X1). In addition, theRS-XOS could the growth of Lactobacillus brevis greater than commercial XOS.

Effects of different strains fermentation on nutritional functional components and flavor compounds of sweet potato slurry

“…The 3,5-dinitrosalicylic acid (DNS) colorimetric method was used to determine the total sugar concentration ( 8 ). High-Performance Liquid Chromatography (HPLC 1515, Waters, United States) was used to examine soluble carbohydrates (fructose, glucose, and trehalose) ( 14 ).…”

“…If sweet potatoes can be treated aggressively to acquire additional nutrients, their use will be substantially enhanced. Microbial fermentation has historically been one of the most prevalent food processing methods (8)(9)(10). Under the influence of beneficial microorganisms, carbohydrates, lipids, and proteins in food materials are decomposed and transformed into distinctive flavors and other nutrients.…”

Natural Xylooligosaccharides Exert Antitumor Activity via Modulation of Cellular Antioxidant State and TLR4

“…XOS are produced from agro-industrial wastes, such as corn cob, wheat and rice straws, tobacco stalks, sugarcane bagasse, and brewers’ spent grains using chemical, physical, or enzymatic methods and their combinations [ 6 , 7 , 8 , 9 , 10 , 11 ]. XOS production by enzymatic hydrolysis with free or immobilized endo -1,4- β - d -xylanase, acting in a synergism with heteroxylan debranching enzymes, is a fast and more eco-friendly method compared with chemical and physical hydrolyses [ 5 , 12 ].…”