Gelling Behavior of Plant Proteins and Polysaccharides in Food Systems

Abstract

Biological macromolecules, such as proteins and polysaccharides, are widely used in food systems because their interactions impart a desirable texture to food products. Plant proteins interact with food components via protein-protein and protein-polysaccharide associations, and the formation of a matrix, which can entrap other food components such as water, lipids and flavors. These networks provide structural integrity to food products and can serve as important functional ingredients in processed foods. Intermolecular interactions of typical polysaccharides result either in simple associations or in the form of a double or triple helix. The linear double helical segments may then interact to form a super junction and a three-dimensional gel network. The formation of these structural networks takes place during processing and involves the transformation from a liquid or viscous sol into a solid material with elastic properties. Interests in the behavior of mixed gels center on the prospects of enhanced flexibility in their mechanical and structural properties compared to those of pure gels. Findings on molecular interactions between plant proteins (e.g., soy, canola and pea proteins) and polysaccharides (e.g., guar gum, carrageenan, and pectin) allow for the modification of physical and textural characteristics of mixed biopolymers to meet desired functional property.

Plant Proteins for Future Foods: A Roadmap

“…Globular proteins can also be employed as gelling agents, because when heated, they unfold, exposing non-polar and sulfhydryl groups to the surrounding aqueous phase, causing aggregation via hydrophobic and disulfide bond formation [4]. Gelation occurs when the aggregated proteins arrange into an ordered matrix with a balance of proteinprotein and protein-solvent interactions, which are maintained by a balance of attracting and repelling forcible forces [37]. Albumins, globulins, glutelins, and prolamins may all form isotropic (e.g., yogurt-like) or anisotropic (e.g., fibrous structures) gels.…”