Selenium Biofortification of Soybean Sprouts: Effects of Selenium Enrichment on Proteins, Protein Structure, and Functional Properties

Abstract

Selenium (Se) biofortification during germination is an efficient method for producing Se-enriched soybean sprouts; however, few studies have investigated Se distribution in different germinated soybean proteins and its effects on protein fractions. Herein, we examined Se distribution and speciation in the dominant proteins 7S and 11S of raw soybean (RS), germinated soybean (GS), and germinated soybean with Se biofortification (GS-Se). The effects of germination and Se treatment on protein structure, functional properties, and antioxidant capacity were also determined. The Se concentration in GS-Se was 79.8-fold higher than that in GS. Selenomethionine and methylselenocysteine were the dominant Se species in GS-Se, accounting for 41.5–80.5 and 19.5–21.2% of the total Se with different concentrations of Se treatment, respectively. Se treatment had no significant effects on amino acids but decreased methionine in 11S. In addition, the α-helix contents decreased as the Se concentration increased; the other structures showed no significant changes. The Se treatment also had no significant effects on the water and oil-holding capacities in protein but increased the foaming capacity and emulsion activity index (EAI) of 7S, but only the EAI of 11S. The Se treatment also significantly increased the antioxidant capacity in 7S but not in 11S. This study indicates that the dominant proteins 7S and 11S have different Se enrichment abilities, and the protein structures, functional properties, and antioxidant capacity of GS can be altered by Se biofortification.

Selenium Speciation in Se-Enriched Soybean Grains from Biofortified Plants Grown under Different Methods of Selenium Application

“…In lettuce accessions, Ramos et al (2011) [ 54 ] reported a large discrepancy in total free amino acids using selenate and selenite as Se sources. In contrast, Huang et al (2022) [ 55 ] found an increase in total amino acids in soybean sprouts that received Se at concentrations smaller than 40 mg L −1 and a decrease in sprouts treated with Se greater than 60 mg L −1 . According to these authors, low-level Se doses promote amino acid synthesis, whereas high-level Se doses have an inhibitory effect.…”

Illumina RNA and SMRT Sequencing Reveals the Mechanism of Uptake and Transformation of Selenium Nanoparticles in Soybean Seedlings

“…They found that during the growth period, part of the inorganic Se was transformed into SeCys 2 , and a larger proportion was transformed into SeMet. In another experiment, SeMet (41.5–80.5%) and MeSeCys (19.5–21.2%) were the dominant Se forms in all selenite-fortified soybean sprouts, while SeCys 2 was only found when Se was applied at the above 30 mg/L [ 60 ]. Here, five Se species, including SeCys 2 , MeSeCys, SeMet, Se 4+ , and Se 6+ , were detected in soybean roots and shoots ( Table 1 ), suggesting that the absorbed SeNPs were converted to oxidative and organic Se species in roots.…”

The influence of selenium on the course of inflammatory diseases of the upper gastrointestinal tract in children

“…Механізм всмоктування мікроелементів практично не відрізняється від всмоктування харчових речовин [17]. На початку вони накопичуються в слизових відкладеннях у пристінковому шарі кишечника, далі абсорбований субстрат (комплекс «мікроелемент + білок слизу») транспортується до базолатеральної мембрани епітеліоцитів, потім через міжклітинний простір, шляхом дифузії через базальну мембрану власної пластини слизової тонкого кишечника та мікропіноцитозу через фенестри ендотеліальних клітин він проникає в кровоносні капіляри [18]. Відомо, що селен є структурною частиною 21-ї амінокислоти -селеноцистеїну [19].…”