Figure 4

CPMAS-TOSS NMR spectra of sugarcane bagasse. (a) Untreated; (b) bagasse treated with ammonium hydroxide (20% v/v NH₄OH, 70°C, 24 h) and (c) delignified bagasse after enzymatic hydrolysis. The spectra were normalized by the intensity of line 10 (C1 carbon of cellulose). CPMAS-TOSS: cross polarization under magic angle spinning with total suppression of spinning sidebands; NMR: nuclear magnetic resonance. * represents the peak which arises due to aliphatic lignin carbons not bound to oxygen.