[Analysis of speciation distribution of se in mungbean during enzymatic hydrolization]

In the present paper, selenium content in mungbean and selenium speciation distribution in mungbean during enzymatic hydrolization was investigated with AFS-230E atomic fluorescence photometer. Selenium in the decoction and enzymatic hydrolysates samples were separated into two species including primary speciation and secondary speciation. The primary speciation included the soluble and the suspended forms and was divided by 0.45 microm filter membrane. The secondary speciation included the inorganic and the organic forms and was divided by D101 macroreticular resin. The speciation parameters of selenium such as extractive rate, remain rate, residue rate, immerse-residue ratio and speciation distribution coefficients, etc in different samples were calculated. The results showed: (1) Selenium content in mungbean was 54.79 microg x g(-1) (of dry matter). (2) Over 90% selenium in mungbean was extracted by enzymatic treatment, but only 19.26% selenium came out in water when only treated by hot water. The extraction rates of Se in the process of amylase, protease and cellulase were 33. 64%, 55.96% and 5.189%, respectively. It was inferred that most selenium was in conjugate or complexation form in mungbean protein. (3) The distribution coefficient of selenium in organic form was 59.87% in the total enzymatic product and 3.64% in the mungbean soup. Organic form distribution coefficients of selenium in amylase and protease hydrolysates were 15.51% and 44.36%, respectively. No organic selenium was detected in cellulase hydrolysate. It was inferred that selenium was in complexation form in mungbean cellulose. All the results showed that enzymatic hydrolization treatment did not only improve the total content of selenium greatly, but also materially improved the organic form content of selenium in water. The recovery for the method was 97.8% and RSD was 1.1% (n=11).