Changes in soy protein immunoglobulin E reactivity, protein degradation, and conformation through fermentation with Lactobacillus plantarum strains

摘要

This study investigated the fermentation of soy protein isolates (SPI) by using 8Lactobacillus plantarumstrains, its reduction effect on immunoglobulin E (IgE) reactivity, and its relationship with protein degradation and conformation changes.L. plantarumshowed potency in reducing IgE reactivity by 83.8%–94.8%, as determined by sandwich enzyme-linked immunosorbent assay. Fermentation resulted in a great reduction (53.8%–92.8%) in soluble protein content and loss of intensity in several major bands, especially those of 7S α’, α, and β subunits, as indicated by electrophoresis. Increased peptide (<10?kDa) content was observed in some fermented samples, especially in those fermented byL. plantarumB1-6 andL. plantarumY-1. Conformation of SPI was altered, as demonstrated by improved surface hydrophobicity (1.6–3.3 times) and emergence of β-strand structure in all fermented samples. Principal component analysis confirmed that peptide (<10?kDa) content, surface hydrophobicity, and β-strand were closely related to IgE reactivity reduction. The reduction of SPI IgE reactivity byL. plantarumwas probably attributed to the alternation in primary and higher structure of the protein.