Research And Application Of Rice Bran Protein And Cellulose

In this work, the extraction and purification of rice bran meal protein, polypeptide and cellulose were researched, by using rice bran as raw material. And the functional characteristics of rice bran meal protein were also evaluated.1. By studying the extraction of rice bran protein and polypeptide, the optimum processing were determined as below: temperature 55℃, p H 10.5, extracting time 120 min, material- liquid ratio1:10. At the optimal parameters, protein extraction rate was 58.26%.2. The optimum processing parameters of enzymatic auxiliary alkali soluble acid sinking method to prepare rice bran protein were determined as below by single factor test and orthogonal test design optimization: temperature 50℃, pH 10.5, time 120 min, material- liquid ratio 1:10, and enzyme amount 2.5%. The protein extraction rate was 75.15% under the above conditions, 16.89% higher than the yield under the alkali soluble acid sinking method.3. The optimum parameters of cellulase to purify the protein were determined as below by single factor test and orthogonal test design optimization: temperature 50℃, pH5.0, time 60 min, cellulase amount 4%, and material- liquid ratio 1:10. The protein purity was 81.57% under the above conditions. The rice protein content and purity were further increased by the optimal of cellulase interpretation, with the protein extraction yield at 57.98% and purity at 81.44%.4. Papaya protease, alkaline protease, papain and neutral protease were used in the hydrolysis of rice bran protein, inspecting the digestion effect of various enzymes, and comparing the different hydrolysis degree on the properties of protein. The results indicated that the alkaline protease is the optimal enzyme with the hydrolysis degree at 17.8%. The color of hydrolysis was brown and transparent. No obvious smelly and significant influence on the sensory of peptide products could be obtained. The optimum process conditions: temperature 50℃, pH 10, extraction time 120 min, enzyme amount 2.5%, and the substrate concentration 3%.5. The optimum parameters to prepare protein and cellulose in rice simultaneously was: temperature 55 ℃, time 150 min, p H 10.0, material- liquid ratio1:10, and ultrasonic power 190 W. The protein extraction rate was 75.58% under the above conditions.6. Although the protein content were similar by comparing the products prepared by alkali soluble acid sinking method and the simultaneous method to prepare the rice bran protein and cellulose, the properties of the protein products in the latter method was better than the former one. Amino acid composition analysis indicated the cysteine content in latter one was lower than the former one, which may influence the heating protein denaturation of the protein prepared by alkali soluble acid sinking method.