The Research On The Microwave Stability Of Selenium-Enriched Rich Bram

Selenium is the microelement which is indispensable of human. It can clear the peroxides and free radicals, prevent the normal cells from damage, inhibit the growth of several tumors, maintain the normal structure of cadiovascular and enhance the immunity. The content of selenium in natural products is pretty low, and it can not meet the body need. Therefore, producing organoselenium which is easy to be absorbed and used with low cost and the immobilization technology of organoselenium are important for the manufacturing of selenium-enriched food.In the present research, selenium-enriched rice bran which was the by-product of the process of selenium-enriched rice was used as raw materials, and organoselenium with high purity was obtained by concentration. Microencapsulation technology was used to fossilize organoselenium in the next step. Results were as followed:1. Peroxidase activity and residual moisture content were key indicators to influence the microwave treatment and the quality of rice bran. Treatment time, heating powder and material thickness were three factors to influence the microwave treatment in sequence. The optimal process parameters for the microwave treatment of selenium-enriched rice bran and general rice bran were heating powder 1000 W, treatment time 90 s and material thickness 20 mm. The residual moisture content after treatment shall be 5% which was the critical value for the charring of rice bran. The FFA of selenium-enriched and general rice bran after microwave treatment was significantly lower than control in storage. Moreover, cold preservation had no effect on the inhibition of lipase. All these results indicated that microwave treatment was very useful for the stabilization of rice bran.2. The best extraction parameters of selenium-enriched and general rice bran were obtained single factor experiments and orthogonal experiments. Antioxidant activity of the two rice bran was compared while the relationship between of selenium content and antioxidant activity was also studied. Both the best extraction parameters for the two rice ran were temperature 50℃, ratio of water and material 1:12, pH 10, and extraction time 3 hours. Antioxidant activity of selenium-enriched rice bran was higher than the general one and the relationship between of selenium content and antioxidant activity depended on the dosage. All these results showed selenium was the the major antioxidant components in selenium-enriched rice bran.3. The amino acid composition and molecular weight distribution of soluble protein in selenium-enriched rice bran were studied by cation exchange column and electrophoresis. The protein content selenium-enriched rice bran in was 5.01mg/ml and its maximum absorption wavelength was 278nm. Moreover, the molecular Weight of soluble protein in selenium-enriched rice bran was 89.2kDa,79.9kDa,70.2kDa,46.8kDa,39.0kDa,19.5kDa,11.7kDa, respectively.