Abstract The search for sustainable alternatives for bioethanol production has encouraged the valorization of agro‐industrial residues. This study evaluated the use of residual barley as a feedstock for bioethanol production and as a potential ingredient for ruminant feed. Three types of residual barley were analyzed: non‐standard grains for brewing (NS), grains contaminated with deoxynivalenol (DON), and pre‐germinated grains (PG), with standard brewing barley (BB) used as a control. Separate hydrolysis and fermentation processes were conducted using the yeast Saccharomyces cerevisiae , with and without nutrient supplementation (yeast extract, ZnSO₄·7H₂O, MgSO₄·7H₂O, and MnSO₄·H₂O). Enzymatic hydrolysis demonstrated high efficiency in reducing sugar conversion, reaching 99% (NS), 96% (DON), and 93% (PG) using Blend 2, with α‐amylase acting for 2 h at 90°C, followed by the addition of amyloglucosidase and cellulase for an additional 6 h at 60°C. Nutrient supplementation significantly increased ethanol yield, reaching 75% (NS), 81% (DON), and 93% (PG) after 24 h of fermentation. The fermentation residues exhibited high neutral detergent fiber contents (65% (NS), 71% (DON), and 65% (PG)), composed of cellulose, hemicellulose, and lignin, indicating suitability for ruminant diets. Residual barley demonstrated strong potential for integrated bioethanol and feed production, promoting circular economy principles and the sustainable valorization of agro‐industrial by‐products.
Berwian et al. (Mon,) studied this question.