Predicting digestibility of Ammonia Fiber Explosion (AFEX) treated rice straw

We modeled the enzymatic digestibility of the Ammonia Fiber Explosion (AFEX) treated rice straw by statistically correlating the variability of the samples to differences in treatment using several different analytical techniques. Lignin content and crystallinity of cellulose affect enzymatic hydrolysis the most. X-ray diffraction was used to measure the crystallinity index while fluorescence and diffuse reflectance infrared (DRIFT) spectroscopy measured the lignin content of the samples. Multivariate analysis was applied to correlate the sugar yields of the various samples with x-ray diffraction and spectroscopic data. Principal Component Analysis (PCA) and multi-linear regression (MLR) techniques could not predict the digestibility of the rice straw samples. The best correlation (R2 value of 0.6) was found between the initial treatment conditions of the AFEX process and the concentration of xylose at 24 hours after enzymatic hydrolysis.