Figure 5
Second derivative of the absorption spectra of Fourier transform near-infrared (FT-NIR) spectroscopy of sugarcane bagasse (SB). (a) Second derivative of the absorption spectra of FT-NIR SB in the range of 6,100 to 5,500 cm-1. The black line represents the SB. The red line, blue line, and green line is the acid hydrolysis with sulfuric acid (H2SO4), alkaline hydrolysis with sodium hydroxide (NaOH), and enzymatic hydrolysis, respectively. The arrows denote the vertical wavenumber for the SB, which provides a better view. (b) Second derivative of the absorption spectra of FT-NIR SB in the range of 5,500 to 4,700 cm-1. The black line represents the SB. The red line, blue line, and green line are the hydrolysis with sulfuric acid (H2SO4), alkaline hydrolysis with sodium hydroxide (NaOH), and enzymatic hydrolysis, respectively. The arrows denote the vertical wavenumber for the SB, which provides a better view. (c) Second derivative of the absorption spectra of FT-NIR SB in the range of 4,500 to 4,000 cm-1. The black line represents the SB. The red line, blue line, and green line are the acid hydrolysis with sulfuric acid (H2SO4), alkaline hydrolysis with sodium hydroxide (NaOH), and enzymatic hydrolysis, respectively. The arrows denote the vertical wavenumber for the SB, which provides a better view. FT-NIR, Fourier transform near-infrared; SB, sugarcane bagasse.