The interaction between starch and phenolic acids: effects on starch physicochemical properties, digestibility and phenolic acids stability

Starch and phenolic acids, two common plant-based food components, can interact to form complexes during food processing, thus improving the functional properties of both starch and phenolic acids. This review provides a comprehensive summary of the effects of the interaction of the two components on the multi-scale structure, and key physicochemical and functional properties of starch, as well as the stability of phenolic acids. The main conclusions are as follows: (i) factors such as starch conformation, specific properties of phenolic acids and experimental conditions influence the extent of starch-phenolic acid interactions; (ii) the formation of the complexes significantly alters the microstructure, crystalline structure and thermal stability of starch; (iii) phenolic acids compete with starch for available free water, thereby altering starch gelatinization. This competition reduces the self-interaction of starch chains and retards the starch retrogradation; (iv) combined phenolic acids alter the structural properties of starch, while free phenolic acids inhibit the activity of digestive enzymes, collectively resulting in decreased starch digestibility; and (v) the thermal stability and biological activity of phenolic acids are closely related to the stability of the structure of starch-phenolic acid complexes. Finally, the review highlights current challenges and future research directions in the study of starch-phenolic acid interactions, aiming to advance the development of starch and phenolic acids in food and industrial applications.