Studies On Ultra-high Pressure、Superfine Grinding、Ultrasound-assisted Chemistry Treatment Of Soybean Dregs

Abstract: With the fresh wet soybean dregs as raw material, firstly, soybean dregsdrying methods were optimized, secondly, dried soybean dregs was processed usinghigh pressure, ultrafine grinding and ultrasonic-assisted chemical, the three treatmentmethods on the influence of physical properties of the bean dregs was studied, thenthe soybean dregs ultrasonic assisted chemical processing conditions was optimizedusing response surface methodology. Finally,the microstructure of soybean dregs aswell as changes in the content of protein subunits was observed using scanningelectron microscope(SEM), SDS-polyacrylamide gel electrophoresis. the crystalstructure of the soybean dregs superfine grinding before and after processing wasdetermined using X-diffraction. The results are as follows:1.In this study soybean dregs drying method was optimized with fresh wetsoybean dregs as raw material.The optimum dry conditions of soybean dregs isdetermined on the basis of obtained soybean lecithin yield in different dry conditions.Study found that the optimum parameters are as follows：microwave drying ofsoybean dregs for4min at270W, followed by hot-air drying for165min at50℃andthe yield of soybean lecithin is2.06mg/g.Microwave hot air drying method not onlyshorten the drying time, but also ensure the quality of the bean dregs, the bean dregsdrying process is a better, worthy of furth-er promotion.2.The changes of the physical properties of the soybean dregs was comparedbefore and after ultrahigh pressure treatment. The results showed that:swellingcapacity, water holding capacity and SDF%content of UHP treatment beandregs were6.94mL/g,6.61g/g,2.25%.6.44%,10.54%,20.97%higher than the untreated soybeandregs.cationic exchange capacity has been enhanced.3.After soybean dregs was dealed with ultrafine grinding processing, the p-articlesize and physical properties changes of the bean dregs in different grinding conditionswas compared. The results showed that:soybean dregs powder sample (averageparticle size≤1.146um) was the best,the swelling capacity,water holding capacity,SDF%content were4.77mL/g,3.62g/g,2.18%, swelling capacity,Water holdingcapacity decreased34.05%,20.24%, but the SDF%of the percentage contentincreased17.20%, cationic exchange capacity was significantly enhanced. Using X-diffraction determined crystal structure of ultrafine grinding soybean dregs beforeand after treatment, Found that the crystallization of soybean dregs remain unaffected.4.After soybean dregs was processed using ultrasonic-assisted chemical.Response surface methodology was used to optimize the ultrasound-assisted chemicaltreatment process conditions.after single factor experiment. The results show that:theoptimum processing conditions were pH4.20, ultrasonic treatment time42min,ultrasonic treatment temperature of55°C.Under this condition, the soybean dregswater holding capacity, the swelling capacity, SDF%percentage content were5.90g/g,6.32mL/g,3.46%,compared with the preprocessed soybean d-regs, water holdingcapacity, swelling capacity were reduced by3.17%,2.38%, The SDF%contentgreatly increased by86.02%.Compared with traditional chemical modification,ultrasonic-assisted chemical method can reduce the amount of acid, speed up thereaction rate, with more advantages, provide a new way for the depth of thedevelopment of the resources of soybean dregs.5.The original soybean dregs and processed soybean dregs was Observed usingscanning electron microscopy (SEM), the results showed that:unprocessed rawsoybean dregs particles were lumpy, lessed surface porosity.the soybean dregssurf-ace after the high pressure treatment showed the lamellar structure, more surfaceporosity and particle volume enlargement, The ultrafine grinding processed soybeandregs particle size was smaller and the surface area was increased;ultra-sound-assistedchemical treatment soybean dregs surface changed and macromolecules fiber breaked,These phenomena consisted with the swelling capacity, water holding capacity SDF%content of the processed soybean dregs.6.The bean dregs was analysised using SDS-polyacrylamide gel electrophoresis.Compared with the original soybean dregs, pressure treatment bean dregs samples7Sprotein subunits content reduced by12.83%,11S protein subunitsincreased0.55%,11S/7S increased from1.23to2.15. therefore, ultrahigh pressuretreatment a greatly influenced the protein subunits content of soybean dregs.Ultrafinegrinding treatment soybean dregs samples7S,11S protein subunit content did notchanged,.therefore, ultrafine grinding process had not effect the content of proteinsubunits of the bean dregs.Ultrasonic-assisted chemical treatment of soybean dregs7S,11S protein subunit content was greatly impacted,7Sreduced by17.68%, the11s increased12.37%,7S/11s increased.11S/7S changedfro-m1.28to2.17, therefore, ultrafine grinding ultrasonic assisted chemical treatment, Ultrasonic-assisted chemical treatment is more significant impact on the soybeandregs protein subunits content, May be the reason of hydrochloric acid was added,affected the content of soy protein subunits.