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: Journal of 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. Journal of 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. Protein products from peas are gaining popularity for their conserved native functionality and environmental benefits. However, yellow pea meal has a few challenges preventing products from entering food markets, including fiber contamination and off-flavors/smells. Fungal fermentation was used to improve quality and broaden the applications of de-hulled pea meal in food markets. This study used fermentation of de-hulled pea meal with six fungal organisms used in food processing and the fermented material was analyzed for changes in phenolic content, phytochemical content, soluble and insoluble dietary fibers, and crude protein. Results showed that fermentation can alter functional characteristics of de-hulled pea meal, including increasing the phenolic content, protein content, saponin concentration and protein solubility, while decreasing the starch content and crude fiber. This creates a better food ingredient with higher levels of protein, antioxidants, and lower levels of starch.

Technical Abstract: With their numerous applications in food, yellow peas are growing in popularity as an ingredient in many foods and food products. However, due to their high content of starch and fiber, their integration in food products is limited. The pea meal components starch and fiber cause gelling and aggregation when cooked which make processing difficult and alter the nutritional profile. In addition, peas contain a secondary metabolite class of compounds known as saponins which are produced and accumulated by legumes and modulated by environmental stressors. Saponins contribute towards bitter flavors and beany odors in peas and pea products. We hypothesize that fungal fermentation may alter and improve the composition and quality of protein in yellow peas, thus improving their integration in food products. This study evaluated the effects of six fungal organisms in the fermentation of dehulled peas for 120 hours. The fermented product was assessed for total phenolic, starch, saponin, and crude protein content as well as overall mass balance. Results showed significant increases in overall protein content and solubility, reduced the overall mass recovery, and resulted in substantial decreases in starch content. Total phenolics and saponin content also increased with fermentation. These findings point to fungal fermentation as a tool for adding value to yellow peas and other crops facing processing similar challenges.