|Title||Low liquid ammonia treatment of wheat straw increased enzymatic cell wall polysaccharide degradability and decreased residual hydroxycinnamic acids|
|Author(s)||Mouthier, Thibaut M.B.; Rink, Bake de; Erven, Gijs van; Gijsel, Peter de; Schols, Henk A.; Kabel, Mirjam A.|
|Source||Bioresource Technology 272 (2019). - ISSN 0960-8524 - p. 288 - 299.|
Food Chemistry Group
|Publication type||Refereed Article in a scientific journal|
|Keyword(s)||Ammonium hydroxide - Lignocellulosic biomass - Low-liquid ammonia (LLA) treatment - Taguchi method - Wheat straw|
Ammonia treatment of lignocellulose improves carbohydrate degradability, however, low ammonia dose treatment effects and mechanisms are hardly considered. This study describes low dose ammonia treatment of wheat straw in a statistical design of experiments (Taguchi design) to evaluate the effects of ammonia concentration, treatment time and the Solid:Liquid ratio on structure, composition and enzymatic degradability of the residual fractions. The results showed that low ammonia concentration (≤2 w/w % NH3) resulted in a high carbohydrate recovery (>80%) coupled enzymatic hydrolysis of 50% of xylan and 40% of glucan of the treated material using a (hemi-) cellulase enzyme cocktail. This effect coincidences with the relative decrease in ferulic acid by 10% and coumaric acid by more than 50% analysed via pyrolysis-GC–MS, measured as 4-vinyl-phenol and 4-vinyl-guaiacol, respectively. Our findings show that lowering ammonia concentration increased the effect of treatment time on the enzymatic degradability of the residual fraction.