Preparation And Characterization Of Rice Reconfiguration Protein

With the rapid development of starch sugar industry, the annual output of ricestarch sugar in2012has been up to1.54million tons and nearly70tons of wet riceresidue was produced. As the main ingredients of rice residue are protein, carbohydrates,fat, of which protein content up to35%-65%, rice residue is an excellent resource toextract rice protein. This article, taking byproduct produced by starch sugar ofChongqing Huidong Biotechnology Co., Ltd. as raw material, studied processoptimization of supercritical CO2degrease of rice residueand process optimization ofpreparation of rice isolated protein; analyzed physicochemical and functional propertiesof rice isolated protein; and explored the enzymatic synthesis of reconstructionsoybeans-rice peptide and the analysis of molecular weight.Experimental results indicate the process of preparating rice isolated protein fromrice residue is: rice residueâ†'supercritical CO2degreaseâ†'hygroscopic expansionâ†'hammer crushâ†'emulsifying dispersionâ†'screening impurityâ†'high shearâ†'hydrolysis impurityâ†'centrifugationâ†'spray dry.Optimal condition of supercritical CO2degrease rice residue is: extraction pressure30MPa, extraction temperature50℃, extraction time60min. On this condition, the fatremoval rate can be up to8.35%.Orthogonal test results indicate: the optimal reaction condition of acid cellulaseenzyme hydrolysis crude fiber of rice residue is: pH=5, solid-liquid ratio1:8,temperature50℃, hydrolysis time120min, enzyme dosage1%. Under this condition,protein content of rice isolated protein reaches87.43%.Functional test results shows that: emulsification, emulsion stability, foaming andfoam stability, water holding capacity, oil absorption of rice isolated protein are greatlyimproved, and significantly higher than rice residue.Optimized hydrolysis conditions of Novozymes alkaline and Flavourzyme proteasehydrolysis of rice protein is: pH=10, temperature55℃, solid-liquid ratio1:15, enzymedosage2%, hydrolysis time180min, under this condition, average molecular weight ofthe rice protein hydrolyzation is621Da, solid content is6.5%; at pH=7,50℃usepurified solution of microbial transglutaminase react with rice peptide and soybeanpeptide for4h, to obtain a reconstructed soybean-rice peptide. Using dextran gel tomeasure molecular weight of crosslinked rice-Soy protein, result shows after crosslinking there are four different molecular weight proteins reconstruction.