Uppal, S.K.Ramandeep Kaur2018-02-182018-02-182016http://krishikosh.egranth.ac.in/handle/1/5810041079Sugarcane bagasse was analyzed for its chemical composition and was found to contain cellulose, hemicellulose, lignin 42.11, 28.42, 19.20%, and glucan, xylan, arabinan, acid insoluble lignin, acid soluble lignin, ash 39.65, 21.46, 2.75, 15.10, 3.31, 3.96%, respectively. Maximum lignin extraction (17.60%) was found to be with 10% NaOH which was further confirmed by scanning electron microscopy images. Lignin was chemically modified by oxidation, acetylation, epoxidation and hydroxymethylation and characterized using FT-IR, 1H, 13CNMR spectra. HPLC analysis revealed p-coumaric acid as major phenolic acid in bagasse lignin (14.76 mg g-1 bagasse) followed by ferulic, vanillic and syringic acid. p-Coumaric and ferulic acid were isolated, derivatized into esters (reactions with alcohols) and amides (reactions with amines, amide linking reagent EDC-HCl (N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide) and 1-hydroxybenzotriazole, HOBt) and characterized by FT-IR, 1H, 13CNMR spectra and elemental analyses. Lignin, modified lignins, phenolic acids and their derivatives were evaluated for antioxidant (DPPH radical scavenging) activity and antibacterial activity against Bacillus aryabhattai, Acinetobacter sp. and Klebsiella sp. Lignin and its oxidized and hydroxymethyl derivative were observed to have higher antioxidant activity than 3,5-di-tert-butyl-4-hydroxytoluene (BHT) and lower than 3-tert-butyl-4-hydroxyanisole (BHA). Phenolic compounds and their derivatives were effective at lower concentrations for antibacterial activity than lignin and modified lignins. Xylooligosaccharides (XOS) were produced from bagasse by xylan extraction (5, 10, 15% KOH and NaOH) followed by acid hydrolysis (0.25 and 0.50MH2SO4; 20, 40, 60min) and analyzed by HPTLC. The best treatment for xylan hydrolysis leading to increased production of XOS and reduced concentration of xylose was found to be 0.25MH2SO4 for 20 min. XOS were found to be better prebiotics for three probiotic bacteria viz. Lactobacillus acidophilus, Lactobacillus brevis and Lactobacillus viridescens than glucose and standard fructooligosaccharides.ennullThesis