Valorization of apple pomace agro‐industrial residue for the production of bioethanol and animal feed ingredients

Abstract Apple pomace, which represents 25–30% of processed apples, is often discarded despite its high carbohydrate content and potential for bioconversion. Owing to its cellulose, pectin, and hemicellulose fractions, apple pomace can serve as a substrate for enzymatic saccharification and alcohol fermentation. This study evaluates the valorization of apple pomace for bioethanol production and animal feed formulation. Bioethanol was produced by separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). In SHF, the enzymatic hydrolysis was conducted using a combination of pectinase, cellulase, and hemicellulase at 50 °C for 6 h, followed by fermentation with Saccharomyces cerevisiae CAT‐1 at 30 °C for 24 h. The SSF process lasted 60 h, with a 2 h pre‐hydrolysis at 50 °C, followed by fermentation with a combination of S. cerevisiae CAT‐1 and Papiliotrema laurentii CHAP‐158 to enhance xylose fermentation. Separate hydrolysis and fermentation achieved a hydrolysis efficiency of 60.70% and a fermentation efficiency of 33.42% in 24 h. In the SSF process, there was a significant increase in ethanol production, reaching 51.70% in 24 h. Residues from SHF showed higher fiber contents, indicating greater suitability for diets requiring resistant fibers. SSF residues had lower fiber levels, making them more appropriate for animals needing more digestible diets, such as high‐producing ruminants or poultry. Simultaneous saccharification and fermentation residues also contained more protein and less lipid, which may influence its nutritional value depending on the specific dietary needs. This study demonstrates the feasibility of using apple pomace for bioethanol production through SSF and the utilization of its by‐products in animal feed.