Different Degreasing Conditions On Rice Bran Protein Extraction And The Influence Of The Structure Research

This experiment with fresh rice bran as raw material, study under the condition of differentdegreasing, proposed four grade rice bran protein.The main research contents and conclusionsare as follows.1. Supercritical CO2extraction of defatted rice bran fresh optimum process conditions are:extraction of35MPa pressure, extraction temperature was50℃,the extraction time was2.5h.Under the best conditions of rice bran protein solubility was69.2%. Ether extractionskimmed fresh rice bran is the best process conditions: degreasing temperature of55℃,degreasing time is2h, ratio of feed liquid1:12(g/mL). Under the best conditions of rice branprotein solubility was44.3%. In two different ways of degreasing, supercritical CO2extractiondefatted rice bran after, can improve the solubility of rice bran protein.2. With supercritical fluid extraction defatted rice bran as raw material, according to theOsbrone method, grading extraction of rice bran. Using response surface analysis, in the finalanalysis out the optimal extracting conditions. Test to determine the optimum extractiontechnology of rice bran albumin parameters for the material liquid ratio of1:11, extractiontemperature45℃, extraction time was3h.Under the condition of the, rice bran protein extractionrate can reach80.95%. Determine the optimum process conditions of the extraction of rice bran)as the material liquid ratio of1:12, extraction temperature is40℃, the extraction time is2.5h,NaCl concentration of2%, in this condition, can get protein extraction rate was79.93%.3. Purification and compare the different defatted rice bran under the condition of four kindsof hierarchical protein, by high performance liquid chromatography (HPLC) method, themolecular weight range of rice bran protein components, molecular weight of the rice branalbumin component range between102.329kDa~57.543kDa, rice bran components of themolecular weight range between95.499kDa~44.668kDa, molecular weight of the rice brangliadin composition range between16.218kDa~13.803kDa, the valley of rice bran proteincomponents of the molecular weight range between56.234kDa~47.8633kDa.4. Test using two color spectrum, and the extracted under the conditions of different defattedrice bran albumin, globulin, gliadin and protein secondary structure determination, using curvefitting software Selcon3[79-80]calculated rice bran four kinds of classification of proteinsecondary structure of alpha helix, beta-fold, beta Angle and the relative content of randomcurl.