Preparation and Antioxidant Properties of Germinated Soybean Protein Hydrolysates

Abstract

In this study, soybeans during different germination stages were described and compared with regard to morphology, water content, protein, amino acids, and isoflavones. The optimal conditions for the hydrolysis of proteins obtained from germinated soybeans were determined using the response surface methodology. Gel filtration chromatography was used to separate germinated soybean protein hydrolysates after ultrafiltration, whereas 2,2-Diphenyl-1-picrylhydrazyl (DPPH), ABTS•+, and FRAP assays were used to assess the antioxidant activity of different fractions. Findings of this study revealed that protein and isoflavone contents were high in soybean at 24 h following germination (the bud was about 0.5–1 cm). The proteins from germinated soybeans were hydrolyzed and separated into five fractions (G1–G5) and evaluated in terms of their molecular weight and antioxidant activity. Interestingly, the antioxidant activity was found to be higher in germinated soybean protein hydrolysates than in other soybean protein hydrolysates derived from soybean meal protein. This suggests that germination can effectively improve the utilization rate of soybean proteins. The antioxidant activity of G3 was best among G1–G5. The results obtained in this study demonstrate that germination for 24 h when the bud length is about 0.5–1 cm can be applied as a special pretreatment of plant seeds in the development of germinated foods. These findings can be used to identify the structure of the potential antioxidative hydrolysates for their possible exploitation in functional foods.

Isolation, identification, and characterization of corn-derived antioxidant peptides from corn fermented milk by Limosilactobacillus fermentum

“…Among them, peptides FPKYPVEPF ( 47 ), and HLPLPLLQSWM ( 48 ) had been identified as antioxidant peptides by different researchers. Antioxidant peptides isolated from soybean hydrolysate and egg white hydrolysate have also been reported to be attributed to histidine due to the protons providing the ability of the imidazole moiety ( 49 ). It has also been reported that the antioxidant activity of peptides in β-casein trypsin hydrolysates VKEAMAPK is derived from methionine ( 50 ).…”

Alternative Protein Sources of The Future: Plants

“…Soya fasulyesi yüksek miktarda protein (%40-50 (w/w)) içeriğine sahiptir [94]. Soya fasulyesi proteinleri, özellikle histidin, izolösin, lösin, fenilalanin, treonin ve triptofan gibi temel aminoasitlerin kaynağıdır [93].…”