Study On The Preparation Of Soybean Oligosaccharide Syrup By Adsorption, Inclusion And Ion Exchange

It is principal to get clear and transparent solution when taking advantage ofoligosaccharides from soybean molasses. This paper adopt two kinds of methods: flocculationand acid precipitation to obtain two clear supernatant. Further debitterizing and decolorizationand desalting treatment were studied in order to prepare soybean oligosaccharide syrup withdifferent purposes when this two kinds of supernatant uesd as raw materials. This paper canprovide a theoretical basis for the comprehensive utilization of soy molasses.Analysis showed that the content of soybean oligosaccharides, soybean isoflavone andsoybean saponin in the supernatant of flocculation was higher, but bitter taste heavy, colordeepper; acid precipitation supernatant was lighter color，bitter taste low, but with higher saltcontent.This paper compared the effect of debitterizing and decolorization of activated carbonmethod, resin adsorpiton and β-cyclodextrin method. Results showed that AB-8resinadsorpiton effect of debitterizing and decolorization on lfocculation soybean molassessupernatant was the best, and the loss rate of total sugar was the lowest. While the use of P-cyclodextrin inclusion method can save soybean isolfavones and soybean saponins and otherfunctional components, but decolorization effect was the worst.Adsorption dynamics of soybean isolfavone on AB-8resin was studied on the basis.Results showed that adsorption content of soybean isoflavone on AB-8resin was11.48mg/g，in line with the pseudo-second order reaction kinetics equation, the adsorption rate couldreach88.31%,97.27%, the adsorption process was controlled by particle diffusion;decoloration rate and removal rate of soybean isolfavone had remarkable positive correlation,the correlation coeiffcient was0.988; the best adsorption condition of the dynamic adsorpitonof AB-8resin column was room temperature, the supernatant of pH5.50，column lfow rate12.96BV/h, the supernatant concentration14%and sample column volume4.32BV; underthis condition, the change rate of A₂₆₀ and A420respectively was79.52%and80.45%，theremoval of soybean saponin, soybean isoflavone rate respectively was86.60%,91.01%; thecontent of soybean oligosaccharides increased from82.55%to91.36%; the70%ethanoldesorption of soybean isoflavone and color material rate respectively was95.52%，88.42%.Research shows that the optimum process conditions of β-cyclodextrin was added3%，temperature45°C，stirring time of25min，under the condition, embedding rate of soybeanisolfavone and soybean saponin and score respectively were45.48%，34.76%and9.02。This paper further compared the desalting and bleaching effect of several kinds of ionexchange resin, then established the method of series column of001><8resin and D301-Gresin for decolorization and desalination from acid precipitation supernatant; Adsorptionkinetics of Na⁺，K⁺，Ca²⁺，Mg²⁺ on001><8resin and adsorpiton kinetics of CI and soybeanisolfavones on D301-G resin were studied. Results showed that maximum adsorpitoncapacities of K⁺，Na⁺，Mg²⁺，Ca²⁺ on001><8resin were29.27mg/g,33.40mg/g,1.47mg/g,0.76mg/g, all were in line with the pseudo-second order reaction kinetics equation, theadsorption rate were82.77%，87.94%，90.77%，96.13%，the adsorpiton process was controlled by particle diffusion; the adsorption content of Cl-，soybean isoflavone on D301-Gresin were37mg/g，5.25mg/g，both were in line with the pseudo-second order reactionkinetics equation, the adsorpiton rate up to88.36%,85.99%, the adsorpiton process werecontrolled by particle diffusion control. Through dynamic study, the best adsorption conditionof the dynamic adsorption of001x8resin and D301-G series ion exchange resin column wasthe volume column ratio of1:2，30%supernatant concentration, temperature, lfow rate of2.6BV/h，pH7，the sample with2BV; under the optimal conditions, the change rate of A260andA420respectively was88.62%and87.08%，the desalination rate was94.89%，content ofsoybean oligosaccharides increased from69.42%to90.62%.Through the above methods，three kinds of soybean oligosaccharide syrup was prepared,the content of flocculation-AB-8resin debitterizing and decolorization oligosaccharides syrupwas59.69%，soy oligosaccharides, soybean isoflavone, soybean saponin and minerals （drybasis） in it were91.23%，0.118%，0.053%and3.26%; the content of lfocculation-β-cyclodextrin inclusion debitterizing syrup was54.5%, soybean oligosaccharides, soybeanisolfavone, soybean saponin and minerals （dry basis） in it were respectively80.91%，0.862%，0.505%and3.72%; the content of acid precipitation-ion exchange-desalting and bleachingsyrup was57.12%，soybean isoflavone, soybean saponins and mineral （dry basis） in it were89.56%，0.013%，0.005%and0.12%.