Effect of solid-state fermentation on the protein quality and volatile profile of pea and navy bean protein isolates

Background and Objectives: Fermentation has been increasingly used as a "clean" processing technique to modify proteins. The goal of this research was to assess the use of solid-state fermentation (SSF) by Aspergillus oryzae on pea (pea protein isolate [PPI]) and navy bean protein isolates (NBPI) for different time periods (0-48 or 0-72 h, respectively) and its impact on their nutrition and volatile profile.Findings: The SSF process resulted in higher total phenolic content and lower protein digestibility, and consequently, the protein quality was reduced for both pulses. The quantity of the volatile compounds initially present in the samples did not change substantially after SSF; however, many new compounds were identified in fermented PPI, which have been reported to have pleasant sensory properties.Conclusions: The protein quality of PPI or NBPI was not improved by A. oryzae SSF; however, the results suggest the potential for using SSF to positively modify the volatile profile of PPI.Significance and Novelty: The findings of this research strengthened our knowledge base of fermented pulse ingredients with the use of protein isolates and navy beans, narrowing the somewhat limited gap for fermentation application to high protein substrates.