FOOD SCIENCE ›› 2021, Vol. 42 ›› Issue (3): 165-172.doi: 10.7506/spkx1002-6630-20200102-014

• Nutrition & Hygiene • Previous Articles     Next Articles

Preparation and in Vivo Absorption Characteristics of Selenium-Enriched Soybean Peptides

GAO Siwei, ZHANG Jian, ZHANG Qiyue, LI Wenhui, LI He, YU Tian, LIU Xinqi   

  1. (1. National Soybean Processing Industry Technology Innovation Center, School of Food and Health, Beijing Technology and Business University, Beijing 100048, China; 2. Enshi Se-Run Health Tech Development Co. Ltd., Enshi 445000, China)
  • Published:2021-02-25

Abstract: The objective of this study was to investigate the absorption characteristics of selenium-enriched soybean protein and peptides derived from it in selenium-deficient rats. Protein was extracted from selenium-enriched soybean by alkali extraction and acid precipitation, enzymatically hydrolyzed, and ultrafiltrated to obtain peptides. The composition, selenium content and distribution, and amino acid contents of the extracted proteins and the hydrolysate were analyzed. Selenium-enriched soybean protein and the peptides with molecular mass below 3 kDa derived from it were orally administered by gavage to SD male rats at a dose of 18 μg of selenium/kg mb. Subsequently, blood samples were withdrawn from the tail at 0, 5, 10, 20, 30, 40, 60, 80, 90 and 120 minutes for measuring and plotting plasma selenium and amino acid contents as a function of absorption time. The results showed that the main selenium-binding subunits of selenium-enriched soybean protein had a molecular mass of 26–35 kDa, and the selenium content of 11S selenium-enriched soybean protein was significantly higher than that of 7S selenium-enriched soybean protein (P < 0.05). The selenium content of selenium-enriched soybean peptides with molecular mass below 3 kDa was 110.40 μg/g, which was significantly higher than that of selenium-enriched soybean peptides with molecular mass of 3–10 kDa and above (P < 0.05), and the methionine (189.32 μmol/g) and cystine contents (47.09 μmol/g) were also significantly higher (P < 0.05). After administration of selenium-enriched soybean protein, plasma selenium concentration peaked at 20 and 80 min, with a maximum value of 1.070 mg/L; plasma total free amino acid concentration peaked at 10 and 80 min, with a maximum value of 4.172 μmol/L. After administration of the selenium-enriched soybean peptides, plasma selenium concentration peaked at 10 and 40 min, with a maximum value of 1.338 mg/L; plasma total free amino acid concentration peaked at 5 and 40 min, with a maximum value of 5.053 μmol/L. Compared with selenium-enriched soybean protein, the peptides advanced the peak concentration times of plasma selenium and free amino acids, and significantly increased the rate of selenium absorption in vivo, suggesting its potential to be developed as a functional oral nutraceutical.

Key words: selenium-enriched soybean protein; selenium-enriched soybean peptide; selenium distribution; nutritional intervention; in vivo absorption

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