Impact of Electron Beam on Storage Protein Subunits, In Vitro Protein Digestibility and Trypsin Inhibitor Content in Soybean Seeds

The present investigation was carried out to study the effect of 4.8, 9.2, 15.3 and 21.2 kGy of electron beam (EB)-irradiation on major storage proteins viz. glycinin (11S) and β-conglycinin (7S), in vitro protein digestibility (IVPD), and trypsin inhibitor (TI) content in seeds of three soybean genotypes. Densitometry of SDS-PAGE protein profile revealed significant (P < 0.05) reduction in α’, α and β subunits of 7S fraction at all doses. This reduction was higher (P < 0.05) than the decline observed in acidic and basic subunit of 11S fraction. Basic subunit registered significant (P < 0.05) increase at specific doses in two genotypes. All the doses induced significant (P < 0.05) increase in IVPD, and the increase due to 9.2, 15.3 and 21.2 kGy was higher (P < 0.05) compared to 4.8 kGy dose. The impact on TI content was genotype-dependent. The study showed a higher (P < 0.05) decline in the concentration of 7S fraction compared to 11S fraction and improvement in IVPD of soybean seeds due to exposure to EB-irradiation, which may influence the functional and nutritional value of soy products processed from them.