الفهرس 
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Abstract
In the last periods, some problems results -#102;-#114;-#111;-#109; consumption of sweeteners, natural and artificial sweeteners, especially to persons with diabetes mellitus and individuals need decreased amount of calories consumption specially. So that, required search for low calorie sugar substitute -#102;-#114;-#111;-#109; natural sources can be safe and suitable to all family. br The present work aimed to study the production of fructooligosaccharides -#102;-#114;-#111;-#109; dried Jerusalem artichoke tubers by application of commercial inulinase enzyme. The fresh tubers were dried by electrical oven, solar drying (at 40, 50, 60 ˚C) and by microwave methods. br Production of microbial enzymes (crude inulinase -#102;-#114;-#111;-#109; A. niger and crude fructosyl-transferase -#102;-#114;-#111;-#109; A. oryzae) and using these enzymes for production of fructooligosaccharides -#102;-#114;-#111;-#109; dried Jerusalem artichoke and sucrose, and application in some functional foods. br The obtained results of this study are summarized in the following points: br Part I: Production of fructooligosaccharides -#102;-#114;-#111;-#109; tubers of dried Jerusalem artichoke by using commercial inulinase br Chemical composition of fresh and dried tubers : br The data of chemical composition of fresh and dried Jerusalem artichoke tubers showed that the moisture content of the dried powders was in the range of 8.7 to 11.22 g/100g D.W. The total carbohydrates were in the range of 74.83 to 77.66 g/100 g D.M. Significant differences in moisture, crude protein, crude fat and ash were found between the different drying conditions. br Optimum conditions of commercial inulinase enzyme on fresh Jerusalem artichoke extracts samples: br The optimum conditions for the application of inulinase enzyme on fresh Jerusalem artichoke extracts were found as follow : ( pH : 5, temperature : 55 ˚C, enzyme concentration : 0.0045 g /30 ml buffer/1L extract, substrate concentration of 180 g fresh tubers /liter and reaction time of 80 min). Under these conditions, the highest yield of 118.85 g total reducing sugar / liter was obtained. br Effect of drying methods at different temperatures on fructo oligosaccharides (FOS) production: br Among the applied drying treatments, solar drying at 60 ˚C and oven drying at 50 ˚C yielded the maximum total reducing sugar of 113.79 and118.85 g total reducing sugar / liter, respectively. br TLC chromatography Analysis: br Thin layer chromatography of the obtained fructooligosaccharide hydrolyzates proved the presence of fructose, sucrose and other low molecular weight fructooligosaccharides in enzymatic treated solutions. br TLC- analysis showed that commercial inulinase enzyme liberated fructose (red spots), Glucose (blue. greenish spot) and other fructooligosaccharides with different DP values -#102;-#114;-#111;-#109; Jerusalem artichoke extracts. The thin layer chromatography could not quantify the concentration of different oligosaccharides. Drying treatments has increased the intensity of the obtained spots for the different separated sugars. br HPLC chromatography analysis: br The total carbohydrates and total reducing sugars composition of the dried Jerusalem artichoke samples was affected by the applied drying method and so also their hydrolysis products obtained by action of commercial inulinase enzyme. The HPLC-pattern of hydrolysis products obtained -#102;-#114;-#111;-#109; the extracts of oven – dried Jerusalem artichoke samples differ than those obtained -#102;-#114;-#111;-#109; the hydrolysis of fresh samples. br The enzyme treated extract obtained -#102;-#114;-#111;-#109; solar – dried sample, has been totally hydrolyzed (100 % conversion) with a sucrose ratio of 6.31%, while the other products consisting of 49.3 % of other sugars with molecular weight higher than sucrose and 44.39 % products with lower molecular weights. The hydrolysis of microwave dried extract resulted in 74.75 % conversion of inulin to other products with lower molecular weights. br On the other side, HPLC – analysis of the hydrolyzates obtained -#102;-#114;-#111;-#109; the dried samples indicated that solar drying of the fresh tubers at 60 ˚C led to the total hydrolysis of inulin by the action of inulinase enzyme, while the oven and microwave drying method led to partial hydrolysis of inulin by 66.87 % and 74.75 %, respectively. br The obtained results proved that the solar drying method at 60 ˚C for 36 h was the most effective method to obtain the maximum yield of fructooligosaccharides by action of commercial inulinase enzyme. br Part II: Microbial production of inulinase and fructosyl- transferase enzymes br br Crude inulinase enzyme Production by A. niger and optimum conditions for production of FOS -#102;-#114;-#111;-#109; inulin by it. br The results -#102;-#114;-#111;-#109; assay of inulinase activity showed that inulinase activity ranged -#102;-#114;-#111;-#109; 6.2 to 8.6 U /ml /min. The optimum conditions of crude inulinase enzyme on inulin (as a substrate) were found as follows: pH: 5, temperature: 55 ˚C, enzyme concentration: 6 ml /100 ml inulin solution, substrate concentration: 1 g inulin /100 ml acetate buffer and reaction time : 80 min. br Crude fructosyl-transferase (Ftase) enzyme Production by A. oryzae and optimum conditions for production of FOS -#102;-#114;-#111;-#109; sucrose by it. br The production of fructosyl-transferase was carried out and Ftase activity was ranged -#102;-#114;-#111;-#109; 13.4 to 16.7 U /ml /min. The optimum conditions were studied for the application of crude Ftase enzyme on sucrose and the results were found as follows: pH: 6, temperature: 60 ˚C, enzyme concentration: 2 ml /100ml sucrose (60 %), substrate concentration: 60 g sucrose /100 ml distilled water and reaction time: 24 h. br The HPLC–chromatograms of fructooligosaccharides -#102;-#114;-#111;-#109; sucrose using crude fructosyl-tranferase showed that the fructooligosaccharides composition was affected by hydrolysis and action of crude fructosyl-tranferase enzyme produced by A. oryzae. The sucrose amount (36.26 %) remained unchanged; while the rest (63.74 %) has been changed to 20.22 % fructooligosaccharides, 18.15 % glucose and 25.03 % fructose. These results indicated that crude fructosyl-transferase have converting power for converting sucrose to fructooligosaccharides and other sugars. br Some physical properties for fructooligosaccharide solutions obtained by microbial enzymes br The physical properties of fructooligosaccharides produced by action of crude inulinase on inulin and action of crude fructosyl-transferase on sucrose were studied for pH, Specific gravity, Refractive index and T.S.S (%). The data showed that fructooligosaccharides produced -#102;-#114;-#111;-#109; sucrose have the highest T.S.S (75 %). the produced fructooligosaccharides -#102;-#114;-#111;-#109; sucrose by Ftase -#102;-#114;-#111;-#109; A. oryzae is suitable for application in foods as a sugar replacer when compared with that produced by crude inulinase -#102;-#114;-#111;-#109; A. niger. br Part III: Application of fructooligosaccharides in some foods br Application in biscuits Production br Sensory evaluation of biscuits samples showed that replacement of sucrose with 50 % fructooligosaccharides -#102;-#114;-#111;-#109; Jerusalem artichoke and 25 % fructooligosaccharides -#102;-#114;-#111;-#109; sucrose by Ftase have given higher taste scores than the control. Fructooligosaccharides -#102;-#114;-#111;-#109; Jerusalem artichoke gave dark color for biscuits samples. The obtained results showed that the supplemented biscuits with FOS -#102;-#114;-#111;-#109; J.A and sucrose were accepted among panellists. br The data showed that biscuits prepared with replacement ratio 50 % FOS -#102;-#114;-#111;-#109; J.A and 25 % FOS -#102;-#114;-#111;-#109; sucrose showed high texture score: 4.13, 4.2, respectively and high score for over all acceptability. This indicated that FOS -#102;-#114;-#111;-#109; dried Jerusalem artichoke mad the good formula to prepare biscuits for diabetic patients as a sugar replacer. br Sensory evaluation for apple nectar br Sensory evaluation of apple nectar showed that replacement of sucrose in control sample by 10 % and 15 % FOS produced -#102;-#114;-#111;-#109; sucrose by Ftase gave the highest scores in sensory evaluation characteristics than that produced -#102;-#114;-#111;-#109; J.A. Whereas, FOS produced -#102;-#114;-#111;-#109; Jerusalem artichoke induced dark color in Apple nectar so that the panellists was rejected these samples. FOS obtained -#102;-#114;-#111;-#109; J.A are not suitable for the replacement of sugar in apple juice, while those of FOS obtained -#102;-#114;-#111;-#109; J.A could be applied without remarkable effect on the colour parameters of the apple nectar. br The obtained results indicated that the best ratio for added fructooligosaccharides as a sugar replacer to apple nectar was 10 %. The tristimulus color measurements showed that the biscuits and apple nectar with FOS -#102;-#114;-#111;-#109; Jerusalem artichoke have dark color.