A comprehensive review of the factors influencing the formation of retrograded starch.

The retrogradation of starch is an inevitable change that occurs in starchy food during processing and storage, in which gelatinized starch rearranges into an ordered state. The chain length, proportion and structure of amylose and amylopectin vary in different types of starch granules, and the process is affected by the genes and growth environment of plants. The internal factors play a significant role in the formation of retrograded starch, while the external factors have a direct impact on its structural rearrangement, and the creation of suitable conditions enables food components to affect the rearrangement of starch. Interestingly, water not only directly affects the gelatinization and retrogradation of starch, but also serves as a bridge to deliver the influence of other components that influence retrogradation. Moreover, there are three mechanisms responsible for forming retrograded starch: the migration of starch molecular chains in the starch-water mixed system, the redistribution of water molecules, and the recrystallization kinetics of gelatinized starch. In this paper, the effects of internal factors (amylose, amylopectin, food ingredients) and external factors (processing conditions) on the formation of retrograded starch and the mechanism controlling these effects are reviewed.