Studies On Extraction Of Compound Amino Acids From Soybean Meal

The soybean meal compound amino acid (SAA) solution extraction process conditions and decolorization technological conditions were optimized, using quadratic regression orthogonal rotating design. Further more, adsorption equilibrium and fix-bed adsorption of SAA were investigated on 732cation exchange resin.First, the quadratic regression orthogonal rotating design was used to optimize SAA extraction conditions, which were Liquid-solid ratio, sulfuric acid concentration, extraction time and extraction temperature. The results showed that the influence degree of various factors on the extraction effect as follows:sulphuric acid concentration> extraction time> extraction temperature, at the same time, regression equation is obtained: y=-243.9-5.41z1-2.88z2+5.50z3+0.576z1z2-0.611z12-0.022z32Its highly significant at α=0.01 level. The highest ammonia nitrogen yield reached 59.9 mg/g under the conditions that the Liquid-solid ratio is 25:1, sulfuric acid concentration is 3.1 mol/L, extraction time is 16.0 h and extraction temperature is 125.0℃, respectively.Second, the quadratic regression orthogonal rotating design was used to optimize SAA decolorization conditions using integrated reactor of cold plasma- photocatalysis-adsorption, which were treatment voltage, treatment time, solution pH, and activated carbon fill rates. Regression equation is obtained: y= 107.34-8.59z3-0.31z4+0.086z3z4+0.44z32Its highly significant at α=0.01 level. The optimum decoloring conditions were:treatment voltage 20 kV, solution pH=3.60, treatment time 11 min and activated carbon filling rate 63%. The decolorization and retention rates of SAA under the optimum conditions were94.8% and 83.1%, respecttively.Third, In the resin adsorption equilibrium experiment of SAA, the results showed that the adsorption of SAA is a exothermic process on 732 cation exchange resin. The equations used Freundlich model fitting the experimental data of adsorption equilibrium, were highly significant at α=0.001 level under different initial pH and temperatures, the average error was less than 3.54%, the maximum error was 6.01%.Finally, The effects of the bed height, flow rate and initial concentration on breakthrough curve in fixed-bed adsorption were discussed. The results showed that the adsorption behavior of SAA in fixed-bed was competitive.