title: Effect of pretreatment severity on the conversion of barley straw to fermentable substrates and the release of inhibitory compounds.
abstract: The production of fermentable substrates from barley straw under various process conditions was studied. Pretreatment included chemical pretreatment with dilute-acid followed by enzymatic hydrolysis; the pretreatment conditions were expressed in a combined severity factor, CS, which ranged in the present study from -1.6 to 1.1. Considering the production of fermentable sugars and the release of inhibitory compounds, the optimal pretreatment conditions were 170°C, 0% sulfuric acid and 60 min, corresponding to CS -0.4. Under these conditions, 21.4 g glucose/L, 8.5 g xylose/L, and 0.5 g arabinose/L were produced, while 0.1g HMF/L, 0.4 g furfural/L, 0.0 g levulinic acid/L, 0.0 g formic acid/L, and 2.1g acetic acid/L were released. The ratio of Σ sugars/Σ inhibitors proved to be a good tool for evaluating the suitability of a hydrolysate for fermentation purposes.
authors: Wageningen UR Food & Biobased Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands. jpanagiotopoulos@gmail.com
authors: I A
authors: IA
authors: Panagiotopoulos
authors: R R
authors: RR
authors: Bakker
authors: T
authors: T
authors: de Vrije
authors: E G
authors: EG
authors: Koukios
mesh_terms: D001709:Biotechnology / Q000379:methods*; D002241:Carbohydrates / Q000032:analysis; D005285:Fermentation; D001467:Hordeum / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D009930:Organic Chemicals / Q000032:analysis*; D013379:Substrate Specificity; D013997:Time Factors; D014866:Waste Products / Q000032:analysis*
chemical_list: D002241:Carbohydrates; D009930:Organic Chemicals; D014866:Waste Products