Role of biopolymers/hydrocolloids as gelling agents in set-yogurt; mechanisms, interactions, characterization

The nutritional and functional qualities of fermented dairy yogurts are highly prized worldwide, primarily due to the complex interactions between hydrocolloids/biopolymers. The use of hydrocolloids in yogurt still faces many unanswered questions despite tremendous progress in our understanding of interactions, especially with regard to the mechanisms underlying processing characteristics and nutritional advantages. Cutting-edge technologies like 3D printing have exciting prospects for determining the roles of hydrocolloids, streamlining manufacturing procedures, and improving their sensory and health qualities. Besides, since the qualities of yogurt are related to the gel formation mechanism, it requires additional consideration. Because they are crucial to the development of yogurt structure and texture, interactions between biopolymers/hydrocolloids are critical when designing yogurt formulations. Furthermore, products that comprise non-interacting biopolymers must be carefully regulated since they have the potential to cause segregative phase separation, which might have a significant impact on the final matrix’s stability and quality. The molecular specifics of the interactions between polysaccharides and casein micelles—which are crucial in giving yogurt products their structure—will be the focus of this review. The potential for generating new microstructures through the interaction or incompatibility of milk proteins with various polysaccharides will be evaluated. Furthermore, we provide an overview of the typical set-type yogurt gel forming process in this article. To comprehend their influence on gel formation and behaviour, the primary ingredients—including biopolymers—as well as their interactions (protein-polysaccharide interaction mechanisms) within the gel are explored. This review examines the interaction mechanisms, such as electrostatic interactions, hydrogen bonding, hydrophobic interactions, and related structural changes, offering new opportunities and theoretical guidance for effectively enhancing the gel properties of yogurt as an important dairy product.