Applied Biochemistry and Biotechnology

, Volume 98, Issue 1–9, pp 23–35 | Cite as

Predicting digestibility of ammonia fiber explosion (AFEX)-treated rice straw

  • Lisa E. Gollapalli
  • Bruce E. Dale
  • Douglas M. Rivers


The enzymatic digestibility of ammonia fiber explosion (AFEX)-treated rice straw was modeled by statistically correlating the variability of samples to differences in treatment using several different analytical techniques. Lignin content and crystallinity index of cellulose affect enzymatic hydrolysis the most. X-ray diffraction was used to measure the crystallinity index (CrI), while fluorescence and diffuse reflectance infrared (DRIFT) spectroscopy measured the lignin content of the samples. Multivariate analysis was applied to correlate the enzymatic hydrolysis results of the various samples with X-ray diffraction and spectroscopic data. Principal component analysis (PCA) and multilinear regression (MLR) techniques did not accurately predict the digestibility of the rice straw samples. The best correlation (R value of 0.775) was found between the treatment conditions of the AFEX process and the concentration of xylose at 24 h after enzymatic hydrolysis.

Index Entries

Lignocellulose enzymatic digestibility lignin crystallinity AFEX correlation pretreatment X-ray diffraction fluorescence DRIFT 


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Copyright information

© Humana Press Inc. 2002

Authors and Affiliations

  • Lisa E. Gollapalli
    • 1
  • Bruce E. Dale
    • 1
  • Douglas M. Rivers
    • 2
  1. 1.Department of Chemical EngineeringMichigan State UniversityEast Lansing
  2. 2.MBI, InternationalLansing

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