The effects of fungal bioprocessing on air-classified pea protein concentrates

Authors: MASSMANN, CAMILLE - South Dakota State University; Berhow, Mark; GIBBONS, WILLIAM - South Dakota State University; KARKI, BISHNU - South Dakota State University

Submitted to: LWT - Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/21/2021
Publication Date: 10/23/2021
Citation: Massmann, C.M., Berhow, M.A., Gibbons, W.R., Karki, B. 2021. The effects of fungal bioprocessing on air-classified pea protein concentrates. LWT - Food Science and Technology. 154. Article 112686. https://doi.org/10.1016/j.lwt.2021.112686.
DOI: https://doi.org/10.1016/j.lwt.2021.112686

Interpretive Summary: This study demonstrates the potential benefits of microbial fermentation processing for new and improved plant protein sources in underutilized crops like yellow peas. Yellow peas are a high-protein pulse crop with many potential food applications. Air-classified protein products from peas are gaining popularity for their conserved native functionality and environmental benefits. However, air-classification of yellow peas has a few challenges preventing products from entering food markets, including fiber contamination and off-flavors/smells. One factor that contributes to the off flavor of concentrated pea protein products is bitterness due to the presence of saponins. Fungal fermentation was used to improve quality and broaden the applications of air-classified pea proteins in food markets. This study used fermentation of air classified pea proteins with six fungal organisms and the fermented material was analyzed for changes in phenolic content, saponin content, soluble and insoluble dietary fibers, and crude protein. Results showed that fermentation can alter functional characteristics of air classified pea proteins, including increasing the phenolic content, protein content, and protein solubility, while slightly lowering the saponin content and crude fiber. This creates a better food ingredient with higher levels of protein, lower levels of indigestible fiber and decreased bitterness.

Technical Abstract: Yellow peas are a high-protein pulse crop with many potential food applications. Air-classified protein products are gaining popularity for their conserved native functionality and environmental benefits. However, air-classification of yellow peas has a few challenges preventing products from entering food markets, including fiber contamination and off-flavors/smells. A commonly recognized source of these off-flavor is due to the presence of saponins, compounds produced as secondary metabolites as a response to pathogens or environmental stress. Fungal fermentation has the potential to improve quality and broaden the applications of air-classified pea proteins in food markets. This study included a 120 h fermentation of air classified pea proteins (0.52 g/g protein) using 6 fungal organisms. Fermented material was analyzed for total phenolic content (TPC), saponin profile, mass balance, soluble and insoluble dietary fibers, and crude protein. Results indicate that fermentation can alter functional characteristics of air classified pea proteins. These alterations include potential increases in TPC, protein content, protein solubility, saponin content, and fiber fractions. Overall, these results demonstrate potential benefits of microbial fermentation processes for new and improved plant protein sources, specifically in underutilized crops like yellow peas.