Background and objectivesThe overall goal of this research was to examine the effect of solid‐state fermentation using Aspergillus oryzae and Aspergillus niger over time on the nutritional properties of an air‐classified pea protein‐enriched flour (PPEF). Specifically, changes to levels of enzyme inhibitors, total phenolics, in vitro protein digestibility (IVPD), and protein quality (IVPD‐corrected amino acid score) were assessed.FindingsTrypsin and chymotrypsin inhibitors were reduced by 11.6 and 30.4%, and 22.8 and 21.8% for A. niger and A. oryzae, respectively, whereas the total phenolic content increased by 35.3 and 44.7% for A. niger and A. oryzae, respectively. IVPD increased over the fermentation time. However, the overall protein quality as measured by the IVPD‐corrected amino acid score became worse, becoming lowered by 5%–15% after 6 hr.ConclusionsSSF improved the digestibility and bioactive compound availability, whereas protein quality was not improved.Significance and noveltyFindings indicate that this particular solid‐state fermentation system improved the digestibility of the PPEF.
Background and objectives
Pea protein‐enriched flour (PPEF) was inoculated with Aspergillus oryzae NRRL 5,590 or Aspergillus niger NRRL 334 to obtain limited protein hydrolysis (0%–10%). Fermented PPEF was analyzed for surface properties, water hydration capacity (WHC), oil‐holding capacity (OHC), and nitrogen solubility and emulsification and foaming properties at pH values of 3.0, 5.0, and 7.0.
Findings
The surface charge of fermented PPEF increased over fermentation time for both fungi, whereas surface hydrophobicity decreased. In all samples, functionality (based on solubility, emulsification, and foaming) was greatest at pH 3.0 and 7.0 and lowest at pH 5.0. Fermented PPEF significantly decreased in solubility over fermentation time for both fungi, and in turn, the foaming properties were negatively impacted, whereas the emulsifying properties remained relatively unchanged. However, fermentation improved the water and oil binding properties of fermented PPEF; WHC increased from 1.46 to 2.03 g/g with A. oryzae, and OHC increased from 1.18 to 2.27 g/g with A. niger.
Conclusions
Fermentation of PPEF with A. oryzae or A. niger may be considered for applications requiring high WHC and OHC, respectively.
Significance and novelty
Fermented PPEF represents a novel protein material that should be further explored for specific food applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.