Modification Technology Of Soybean Dregs Dietary Fiber And Design Of A Factory With An Annual Output Of 500 Tons Of Soybean Dietary Fiber

Soybean dreg is a by-product in the processing of traditional soybean products in China.About 20 million tons of wet soybean dreg is produced every year,but it is often discarded because it is perishable and has beany flavor.Soybean dregs are rich in nutrients,including 70%dietary fiber,16%protein and other active substances.As an important and economical source of dietary fiber,soybean dregs can be used as raw materials for processing functional foods.However,the main component of soybean dreg is insoluble dietary fiber（IDF）,which limits its application in food processing.Therefore,it is necessary to modify the dietary fiber（DF）of soybean dregs by various methods in order to increase the content of soluble dietary fiber（SDF）so as to make better comprehensive utilization of soybean dregs.In this thesis,soybean dreg was hydrolyzed by protease to remove protein impurities.The color and appearance of soybean dreg were improved by decolonization with H₂O₂.Then,the dietary fiber of soybean dreg was modified by high temperature cooking,cellulose enzymolysis,ultrafine grinding and ultrafine grinding combined enzymolysis.The physicochemical and functional properties of the modified dietary fiber were investigated and characterized by scanning electron microscopy,fourier transform infrared spectroscopy and X-ray diffraction spectroscopy.After that,the high quality dietary fiber powder of soybean dreg after ultrafine grinding was used as raw material added with different auxiliary materials to be pressed into tablets by dry method.The sensory evaluation,physical properties and texture characteristics of the tablets were investigated,and the optimal tablet formulation was selected.Finally,a factory with an annual output of 500 tons of high quality soybean dregs dietary fiber was designed.The main results were as follows:The basic components of soybean dreg were as follows:9.38%moisture content,9.53%protein content,2.98%ash content,3.63%fat content,86.74%total dietary fiber content.Response surface experiment was used to optimize the process of removing soybean dregs protein by enzymolysis.The optimal conditions were as follows:temperature 44.87℃,time 2.13 h,ratio of enzyme activity to substrate 7960.8 U/g.Under these conditions,the removal rate of soybean dregs protein could reach 63.03%.At the temperature of 45℃,time of 2.1 h,the ratio of enzyme activity to substrate of 7900 U/g,the verification test was carried out,and the removal rate of soybean dregs protein was62.73%.Furthermore,the effects of different concentrations of H₂O₂ on the decolorization effect of soybean dreg were investigated under different pH values.It was found that the best decolorization effect was achieved when the concentration of H₂O₂was 7%and the pH value was 10,and the whiteness value of soybean dreg reached 92.6.The SDF content of soybean dreg increased to 9.2%,9.56%,16.11%and 11.89%after high temperature cooking,enzymatic hydrolysis,ultrafine grinding,ultrafine grinding and enzymatic hydrolysis modification,respectively,all of which were significantly improved（p<0.05）,and the ultrafine grinding effect was better.At the same time,the water holding capacity,swelling capacity and water soluble capacity were improved obviously,while the oil holding capacity decreased.The inhibition of glucose adsorption capacity,α-amylase activity and NO₂^-ion adsorption capacity increased in different degrees.After high temperature cooking and ultrafine grinding,the glucose adsorbability of DF in soybean residue reached 524.9μg/g and 587.67μg/g,respectively.The inhibition rate of amylase activity increased from 12.47%to 29.85%and 36.91%in the high temperature cooking and ultrafine grinding groups,respectively,and reached19.16%in the enzymatic hydrolysis group.The adsorption capacity of NO₂^-reached216.17,237.95,180.92 and 217.66μg/g,respectively,and the adsorption capacity was significantly improved（p<0.05）.In addition,the results of fourier transform infrared spectroscopy,scanning electron microscopy,and X-ray diffraction spectroscopy showed that the main groups of soybean dregs DF almost were not changed after modification,and the structure was looser.Macromolecular cellulose and hemicellulose were degraded into small molecular polysaccharides and monosaccharides.More pores and network structures were exposed,and the powder particle size was smaller after ultrafine grinding,and the specific surface area greatly increased.The above results indicated that the modified soybean dregs DF after ultrafine grinding and high temperature cooking may play a certain role in inhibiting the increase of postprandial blood glucose concentration,preventing and improving the symptoms of diabetes,and preventing cancer.Using ultrafine bean dregs powder for tableting experiment,after formula screening and index determination,formula 8（60%superfine bean dregs powder+10%malt dextrin+2%magnesium stearate+28%sorbitol）showed that all indexes were relatively better,with moderate hardness 16.31 N,small chewiness 5.0 m J;the sensory evaluation score was 87 points;it was observed by the stereomicroscope that the tablet surface of the formula was smooth,the color was bright,and the appearance was highly acceptable.Finally,according to the relevant requirements,the annual output of 500 tons of soybean dregs dietary fiber factory was designed.The site selection was carried out;the production workshop layout diagram and equipment production process flow chart were determined;the production equipment and equipment model were determined;according to the legal working hours and annual production requirements,employees were arranged to work 250 days a year,12 hours a day,2 shifts a day.The annual water consumption was estimated to be 62,970 t,the annual electricity consumption was estimated to be489,087.5 k W h,and the annual steam consumption was estimated to be 28600 t.According to the technical and economic analysis,at the beginning of the plant,the fixed asset investment was predicted to be about 12.6 million yuan,the annual current asset investment was predicted to be about 10.7542 million yuan,the annual sales was predicted to be about 20 million yuan,the annual net profit was predicted to be about4.5858 million yuan,and the investment recovery period was predicted to be about three years.At the same time according to the actual production and related requirements,a set of soybean dregs dietary fiber production enterprise standards was established.