The role of protein and its hydrolysates in regulating the digestive properties of starch: A review

Starch and proteins are found in many flour-based food products, and they provide the energy and nutrients the human body needs. The interactions between them often significantly affect the structure and properties of starch. Studying the interactions of protein and its hydrolysates with starch under different processing conditions and the mechanisms by which they affect the digestive properties of starch can provide a theoretical basis for the design and production of starch-based food products with good nutritional functions. In vivo or in vitro, proteins can be hydrolyzed by acid, base, or protease. During hydrolysis, proteins are broken down into peptides with small molecular weights and finally hydrolyzed into amino acids. This study aims to review the effects of endogenous or exogenous proteins in food and their hydrolysates (peptides and amino acids) on the structure, properties, and digestibility of starch, and the interactions of starch with proteins or protein hydrolysates under specific processing conditions. On this basis, we consulted relevant literature and summarized the reasons for the influence of protein and its hydrolysates on starch digestibility. Proteins and protein hydrolysates (peptides and amino acids) have different effects on the microstructure, crystal structure, chemical structure, and thermal stability of starch under different conditions. In addition, protein and its hydrolysates can regulate the digestive properties of starch and can be used as ingredients for low-glycemic starch-based food.