The application and mechanism of polysaccharides, proteins and their complexes on enhancing yogurt gel stability: a review

Yogurt is highly sought after by consumers because of its unique flavor, rich nutritional value and health care function. However, during its sale and storage, some undesirable phenomena such as unstable gel structure and whey precipitation are prone to occur, which has affected the further development of yogurt industry to some extent. Polysaccharides and proteins act as typical thickeners and stabilizers in food, enhancing the structural stability of yogurt gel through different mechanisms. Anionic polysaccharides interact with casein electrostatically to form complexes, while neutral polysaccharides rely on their hydration capacity and act as fillers to stabilise the three-dimensional structure of yogurt. Milk proteins and vegetable proteins play a stabilising role mainly through hydrophobic interactions and disulphide bonds. Gelatin, on the other hand, relies on its good hydration capacity and gelation properties. Polysaccharide and protein complexes mainly rely on non-covalent interactions to stabilise the yogurt gel structure. This paper reviewed the mechanisms of yogurt gel formation and the factors that affect yogurt texture. It also summarized the research progress on enhancing the structural stability of yogurt gel using polysaccharides and proteins as well as their complexes as additives, with a view to providing theoretical bases for improvement of the textural properties of yogurt.