Utilization of Agricultural Waste for the Production of Xylooligosaccharides Using Response Surface Methodology and Their In Vitro Prebiotic Efficacy

Abstract

Air pollution is a prominent problem recently faced in various parts of India due to the burning of stubbles (coconut husk, corn cob, paddy stubbles, sugarcane bagasse, etc.) which are rich in a lignocellulosic component that can be converted into a prebiotic known as Xylooliogsaccaride (XOS). They can be produced by autohydrolysis, acid hydrolysis and enzymatic hydrolysis of xylan. In the present study, Xylan was extracted from sugarcane bagasse using two alkalis (NaOH and KOH) and the yield was compared. Xylooligosaccharide produced by enzymatic hydrolysis and their factors influencing the yield were optimized using Response Surface Methodology. Xylan and Xylooligosaccharide was characterized by FTIR, NMR, XRD, TGA and ESI-MS. Xylooligosaccharides was investigated for their prebiotic potential by in vitro study. The maximum (Relative yield of 86%) yield of xylan was observed in 20% of NaOH. Xylan peaks at 3762cm-1, 3347 cm-1, 2917cm-1 represents the OH and CH stretching of xylan. The main signals at 4.26 (H-1), 3.19 (H-2), 3.59 (H-3), 3.63 (H-4) and 3.98 (H-5) ppm determines the existence of xylan. The higher amount of XOS is pH 4.75, temperature 45°C, enzyme 4U/ml and for time of 16h. The spectrum of 5.0-5.40ppm and 4.30-4.60ppm represents the α anomeric and β anomeric protons in XOS. They are resistant digested and the reaching percentage to the intestine is 95% unhydrolyzed. The maximum prebiotic index was noted in L.plantarum (1.92) and L.fermentum (1.61). The highest prebiotic index and score was observed in L.plantarum (1.9) and L.fermentum (17). The maximum bacteriocin production of Enterococcus faecium against E.fecalis (13mm) and Streptococcus pyogenes (11mm). Therefore, utilization of agricultural residues for a value-added product not only shows a great impact on environmental issues but also could double the farmer’s income