Effect of amylose/amylopectin ratio of esterified starch-based films on inhibition of plasticizer migration during microwave heating

- Film amylose/amylopectin ratio affected DEP migration during microwave heating.
- The strong interaction between starch and DEP of waxy film inhibited DEP migration.
- Further amorphization of G50 film in microwave process favored DEP migration.
- Damaged crystalline structure of G80 film in microwave process favored DEP migration.
- The smallest size of micro-ordered region of G80 film favored DEP migration.

Plasticizer, as a necessary processing aid in producing packaging materials, migrated into food stuffs, which caused food safety problems. In order to restraint plasticizer migration, the hydrophobic esterified starch-based films with different multi-scale structures were prepared by regulation the ratio of amylose and amylopectin. The influence of multi-scale structures including molecular interactions between plasticizer and esterified starch, crystalline structure and aggregation structure on inhibition of diethyl phthalate (DEP) migration during microwave heating was studied. As the strongest molecular interactions between starch and DEP, the amount of plasticizer migration in waxy film was lower than that of G50 film and G80 film. Even the largest size of micro-ordered region impeded the DEP movement in G50 film, the serious further amorphization in G50 film amorphous region in microwave process and weaker molecular interactions led to higher DEP migration compared with that of waxy film. The amount of DEP migration in G80 film were the largest which resulted from weaker molecular interactions, damaged crystalline structure during microwave process and the smallest size of micro-ordered region. This study provided a new method to control DEP migration which favored the application of esterified starch-based biodegradable material for food packaging.