Study On Processing Of Se-Enrichment Germinating Soybean And Distribution Of Se In Its Sporut

In this paper, soybean seeds were soaked in solutions of sodium selenite and then germinated with distilled water. The growth of the soybean sprout and the amount of selenium (Se) accumulation were studied under different steeping conditions of soybean. The germinating process of soybean rich in Se was optimized by parameters of the germination rate and the total Se (T-Se) content. This study also investigated Se distribution in different parts of Se-enriched soybean sprouts and its accumulation in protein fractions. Physical and chemical characterizations were investigated during germination.The major work was summarized as follows:After 96 h germination, the germination rate was 97.85%, sprout length was 17.62 cm. The content of organic Se (O-Se) and T-Se was 4.36μg/g and 11.95μg/g, respectively. Box-Behnken experimental design showed that the optimal conditions for Se accumulation during soybean germination were Na2SeO3 concentration of 50 mg/L, at a steeping temperature of 30℃and steeping time of 4 h. Under these conditions, the maximal germination rate and T-Se content were 91.16% and 10.70μg/g dry weight, respectively. The optimal incubation temperature was 25℃.The physiological activity and chemistry components significantly changes during 120 h germination in soybean cultivars. The sprout length increased 17.32 cm, moisture content was increased 1.53 folds, respiratory rate was improved 20.55 folds, protease activity increased 3.54 folds compared to pre-germination, free amino acid and reducing sugar increased 5.47 and 10.07 folds, respectively, soluble protein and total sugar decreased 88.24% and 28.02%, the T-Se content first reduced and then increased, while the O-Se content gradual increased, the rate of O-Se to T-Se increased.Soybean seeds were steeped with 50 mg/L sodium selenite at 30℃for 4 hours and then germinated with distilled water at 25℃for 4 days. The distribution of Se in different parts of Se-enriched soybean sprouts and its accumulation in protein fractions were investigated. The results showed that, after germinated for 4 days, the distribution of Se in different parts were:radicle> hull> hypocotyl> cotyledon. The Se contents in soluble biological macromolecules from high to low were as follows:soluble protein, nucleic acid, and polysaccharide. The Se contents of the different protein extractions were in the following order:Water-soluble protein-bound Se> Alkaline-soluble protein-bound Se> Salt-soluble protein-bound Se> Alcohol-soluble protein-bound Se.