Soluble pea protein aggregates form strong gels in the presence of κ-carrageenan.

Abstract: Pea protein has emerged as an alternative to soy protein, yet its limited gelling properties have constrained its application in food formulations. This study developed a method to prepare heat-induced soluble pea protein aggregates, followed by the heat induced gelation of the soluble pea protein aggregates in the presence of a small amount of κ-carrageenan. Analysis of mechanical properties revealed that the resulting composite gels can be adjusted to achieve compressive strengths reaching up to 14.15 kPa. Notably, these robust gels were formed using low concentrations of protein (7.5%) and κ-carrageenan (0.5%), making them advantageous for practical use. Characterizations involving surface hydrophobicity, transmission electron microscopy (TEM), and FTIR indicated that pea protein particulate aggregates, possessing surface hydrophobic patches, acted as crucial building blocks. These aggregates facilitated the formation of a uniform three-dimensional network composed of highly crosslinked structures with small pore size. As a result, the gels exhibited superior mechanical strength compared to gels produced from pea protein isolate combined with κ-carrageenan. This research has provided a novel approach for structuring and texturization of plant protein based foods by using protein aggregates and contributed to the understanding of mechanism of gel formation from pea protein aggregates in the presence of κ-carrageenan.