Improved Processability of Soy Proteins Due to Conformational Controls under a Combination of Chemical and Mechanical Treatments

• Published in: ACS agricultural science & technology Vol. 1; no. 1; pp. 11 - 20
• Main Authors: Zou, Jiahan, Nguyen, Ngoc Thi-Hong, Biers, Mae Devorah, Sun, Gang
• Format: Journal Article
• Language: English
• Published: American Chemical Society 15.02.2021
• Subjects: soy protein isolate; structural dissociations; SPI−cellophane films; surface charge; hydrophobic interactions; hydrogen bonds
• ISSN: 2692-1952; 2692-1952
• DOI: 10.1021/acsagscitech.0c00050

Conformations of soy proteins in soy protein isolate (SPI) aqueous dispersions determine the processability of the SPI and are affected significantly by pH conditions and the addition of a plasticizer, when mechanical forces are present. In this work, the effect of chemical forces facilitating the physical treatment in modifying the conformational structures of soy proteins was investigated. SPI in a H2O system under extreme pH conditions and a glycerol/H2O system was subjected to a combination of ultrasound and shear (USSH) treatments to increase the processability of soy proteins by conformational denaturation. In the H2O system, the combination of the USSH treatment and different pH conditions provides varied properties of denatured SPI solutions and fabricated SPI–cellophane composite films. In the glycerol/H2O system, with an increased and stabilized viscosity, a higher content of sulfhydryl groups, swelled particle sizes, and unfolded protein structures, glycerol proved to be an efficient structural stabilizing agent assisting the deformation of soy proteins under the USSH treatment. The combinations of the USSH treatment and extreme pH conditions or the glycerol/H2O system proved to be efficient processing methods for increasing the processability of soy proteins as a raw material in products.