Faculty of Biotechnology and Food Sciences in Nitra Journal of Microbiology, Biotechnology and Food Sciences 1338-5178 vol. 7 2017 2017-10-01 2017-10-01 BY-PRODUCTS OF DATES: OPTIMIZATION OF THE EXTRACTION OF JUICE USING RESPONSE SURFACE METHODOLOGY AND ETHANOL PRODUCTION 204 208 EN Sofien Chniti Sofien Chniti Monia Jemni Monia Jemni Imen Bentahar Imen Bentahar Mohammad Ali Shariati Mohammad Ali Shariati Hayet Djelal Hayet Djelal Abdeltif Amrane Abdeltif Amrane Mnasser Hassouna Mnasser Hassouna The optimal extraction conditions were determined for by-product of date fruit by using the response surface design method. The obtained juice was used for the production of ethanol by fermentation of free cells of Saccharomyces cerevisiae. Optimal conditions for date juice extraction were found to be 80°C, 60 min, 1:2 dilution (fruit on water ratio) according to the result of response surface analysis (Equivalents glucose: 219 g.L-1). Saccharomyces cerevisiae showed a preference for glucose over fructose and among the tested total sugar concentrations, namely 50, 100, 174 and 358 g.L-1, 174 g.L-1 appeared to be the optimal amount, leading to 70 g.L-1 ethanol concentration after 66 h of fermentation,; while an inhibitory effect of a high sugar content, 358 g.L-1 of total sugars, namely about 2 mol/L of monosaccharide like glucose or fructose was also shown. Overall, this study suggested that date juice can be utilized for ethanol production.