Effect of low severity dilute-acid pretreatment of barley straw and decreased enzyme loading hydrolysis on the production of fermentable substrates and the release of inhibitory compounds

► We studied the decrease of pretreatment severity and enzyme loading. ► We monitored the production of 4 fermentable sugars and 5 inhibitory compounds. ► The enzyme loading of 15 FPU/g straw was needed for 50% carbohydrate conversion. ► We discussed the ethanol and hydrogen fermentability of the hydrolysates.