Enzymatic hydrolysis of cellulose present in apple pomace was investigated using process variables such as enzyme activity of commercial cellulase, pectinase and beta-glucosidase, temperature, pH, time, pretreatments and end product separation. The interaction of enzyme activity, temperature, pH and time had a significant effect (P < 0.05) on release of glucose. Optimal conditions of enzymatic saccharification were: enzyme activity of cellulase, 43 units; pectinase, 183 units; beta-glucosidase, 41 units/g dry matter (DM); temperature, 40 degrees C; pH 4.0 and time, 24 h. The sugars were fermented using Saccharomyces cerevisae yielding 19.0 g ethanol/100 g DM. Further bio-conversion using Acetobacter aceti resulted in the production of acetic acid at a concentration of 61.4 g/100 g DM. The present study demonstrates an improved process of enzymatic hydrolysis of apple pomace to yield sugars and concomitant bioconversion to produce ethanol and acetic acid. (C) 2012 Elsevier Ltd. All rights reserved.