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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food Processing and Sensory Quality Research » Research » Publications at this Location » Publication #424473
Research Project: Biochemical Approach to Protein Processing, Texturization and Nutritionally Beneficial Plant-based Foods

Location: Food Processing and Sensory Quality Research

Title: Reducing agents aid in the texturization of pea protein isolate during high moisture extrusion

Author
item BERNIN, JOSHUA - Washington State University
item WATANABE, PRESTON - Washington State University
item Smith, Brennan
item KOWALSKI, RYAN - Washington State University
item GANJYAL, GIRISH - Washington State University

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/8/2025
Publication Date: 1/13/2026
Citation: Bernin, J., Watanabe, P., Smith, B., Kowalski, R., Ganjyal, G. 2026. Reducing agents aid in the texturization of pea protein isolate during high moisture extrusion. Journal of Food Science. https://doi.org/10.1111/1750-3841.70797Digital Object Identifier (DOI).
DOI: https://doi.org/10.1111/1750-3841.70797Digital Object Identifier (DOI)

Interpretive Summary: This study investigates how disulfide bonds contribute to the texture of plant-based meat alternatives during extrusion. Researchers added different reducing agents (sodium metabisulfite, cysteine, and glutathione) to pea protein and extruded the mixtures at 130°C and 150°C. While the reducing agents broke disulfide bonds, they significantly altered the texture, structure, and integrity index, affecting the final product. The best texture was achieved with 0.05% glutathione at 150°C. The findings suggest that while disulfide bonds play a role in texturization, other factors also influence the development of a fibrous, meat-like consistency.

Technical Abstract: One of the leading hypotheses of plant protein texturization during extrusion is the formation of disulfide bonds though extrusion. This study aims to better understand the role of disulfide bonds during the texturization of plant-based high moisture meat analogs. Pea protein was blended with three reducing agents, sodium metabisulfite, cysteine, and glutathione at varying levels of inclusion. The blends were extruded using a co-rotating twin-screw extruder at two different temperature settings of 130°C and 150°C. The feed rate (60g/min), screw speed (100 rpm), and moisture content (60% w.b.) were kept constant. The extrudates were subjected to polymeric protein size exclusion, disulfide, and thiol bond quantification, integrity index analysis, and anisotropic index. The reducing agents cleaved disulfide bonds and significantly affected the structure, texture, and integrity index of the extrudates. The reducing agents also had varying effects on the extrudate and the flow of the melt with the best product obtained with 0.05% glutathione inclusion extruded at 150°C. Although the reducing agents had a relatively small impact on the disulfide bonds, it had a major impact on the physical characteristics of the product and the crosslinking of proteins.