Secondary Utilization Technology Research Of Orange Peel

A large amounts of residue will be produced after extracting pectin and hesperidinfrom orange peel, which contains a lot of useful components, if you don’t use them notonly cause the waste of resources, but also produce pollution to the environment.However, the further research and development of the residue has economic and socialbenefits. This study focused on extracting dietary fiber and producing ethanol by usingof the residue, which will realize the secondary utilization of citrus peel, and maximizeeconomic benefit of citrus industry.First of all, the extraction technology of dietary fiber are studied, and developedthe alkali soaking, acid hydrolysis, H2O2decolorizing three-step process. On the basisof single factor experiment and optimized through the orthogonal experiment, theresults showed that the optimum conditions of dietary fiber are:(1) alkali soaking:0.25mol/L of the sodium hydroxide concentration, alkali soaking temperature50℃,alkali soaking time1.0h, and solid-liquid ratio1:15(g/mL);(2) acid hydrolysis: pH2,acid hydrolysis temperature60℃, acid hydrolysis time1.0h, solid-liquid ratio1:20(g/mL);(3) the decolorizing: H2O2concentration is4%, decolorizing temperature60℃and decolorizing time3h and pH9. In this condition, the yield of insolubledietary fiber is65.98%, the withdrawal rate is as high as92.86%and the product coloris ivory and accordance with the requirements of the level of the quality of soybeandietary fiber.Secondly, this paper discussed the conditions of the orange peel’s enzymehydrolysis saccharification. The orange peel residue enzyme hydrolysis by usingcellulose enzyme, and the effects of enzyme dosage, solid-liquid ratio, pH, enzymehydrolysis temperature, enzyme hydrolysis time on enzymatic hydrolysis were studiedby single factor experiment. On this base, a L9(34) orthogonal experiment was designed,the results shows that the optimal conditions of the enzyme hydrolysis saccharificationis: enzyme dosage is1/50(g/g), solid liquid ratio1:30(g/mL), pH5.0, enzymehydrolysis temperature50℃. In this condition, the reducing sugar yield reached69.48%.Finally, the fermentation technology conditions of using the orange peel residue toproduce ethanol were investigated. Choosing Angela dry yeast, Dan polly dry yeastand ab mauri dry yeast strains for fermentation, and the fermentation performance of three strains were compared, finally choosed Dan polly dry yeast as strain. On thebasis of single factor experiment, the orthogonal optimization the fermentationconditions of preparation of ethanol from enzyme hydrolysis saccharification liquid ofthe orange peel residue. The results show that the optimal conditions of fermentation is:inoculation quantity is1%, fermentation time24h, pH5.0, fermentation temperature27℃, under this conditions, ethanol production rate reached15.43%.