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Abstract Ahmed Sayed Ahmed El-sayed Younes: Bio-Conversion of Some Food Processing Wastes for The Production of Economically Valuable Products. Unpublished M.Sc. Thesis, Department of Food Science, Faculty of Agriculture, Ain Shams University, 2017. This study was designed to produce fructose syrup (FS) by enzymatic hydrolysis. This enzymatic hydrolysis was carried out using inulinase enzyme that obtained from the fermentation process of cellulosic substrates using the yeast Kluyveromyces marxianus NRRL Y-7571 under solid state fermentation of raw materials that store inulin as a main carbohydrate. Nine solid state substrates, sugarcane bagasse (100%), potato peels (100%), artichoke leaves (100%), bagasse : potato peels (50%:50%), bagasse : artichoke leaves (50%:50%), potato peels : artichoke leaves (50%:50%), bagasse : potato peels: artichoke leaves (20%:30%:50%), bagasse : potato peels : artichoke leaves (30%:50%:20%), bagasse : potato peels : artichoke leaves (50%:20%:30%) were tested to select the most suitable medium for inulinase production using the yeast Kluyveromyces marxianus NRRL Y-7571 under solid state fermentation. The best cellulosic waste ratio was bagasse : artichoke leaves (50:50%), the inulinase activity reached to 414.72 U/g substrate and its specific activity was 669.81 U/mg protein. The optimum conditions for K. marxianus NRRL Y-7571 growth and inulinase production had been studied and were found to be as follows: incubation period: 2 days, incubation temperature: 30°C, initial pH in solid state medium: 6, inoculum size: 2 ml/5g waste, moisture content of solid state medium: 60% and waste ratio of sugarcane bagasse : artichoke leaves were 75:25 w/w. Under these conditions, it was showing up an inulinase activity and specific activity of 1252.08 U/g substrate and 1421.98 U/mg protein, respectively. The produced inulinase under the obtained optimal conditions was partially purified by ammonium sulfate using dialysis technique. This step caused an increase in the specific activity of inulinase enzyme to 1841.42 U/mg protein. The optimum conditions for inulinase activity were found to be as follows: incubation period: 30 min, incubation temperature: 55°C, optimum pH: 4.8, substrate concentration: 0.5%, enzyme size in mixture reaction: 150 µl and agitation speed: 100 shake. Under these conditions, it was observed an inulinase activity and specific activity of 1835.61 U/g substrate and 3078.68U/mg protein, respectively. Some important industrial parameters for produced inulinase enzyme were studied like thermal stability and pH stability, the results referred that inulinase enzyme was stable up to 55°C and pH value range between 4 - 6, respectively. The obtained optimum conditions for inulinase activity were applied to hydrolyze the inulin that extracted from jerusalem artichoke for the production of fructose syrup to use for supplement food manufactures process. The produced fructose syrup (FS) was applied in biscuits manufacture, physical properties (width, thickness and spread ratio) and sensory evaluation (color, texture, odor, taste and over acceptability) showed that biscuits which produced without commercial fructose syrup and replaced with 60% by the produced fructose syrup from the water ratio in the control formula gave higher scores for physical and sensory evaluations than other treatments and control. It could be recommended that commercial fructose syrup could be replaced with 60% by the produced fructose syrup under this study to produce cheaper product and more acceptable for the customer that achieved higher profit to food processing factories. Key words: Sugarcane bagasse, Potato peels, Artichoke leaves, Jerusalem artichoke, Corn steep liquor, Kluyveromyces marxianus NRRL Y-7571, Solid state fermentation, inulinase production, Inulin, Biscuits, Fructose syrup. |