Preparation and characterization of chitosan / corn starch based films loaded with Vaccinium vitis-idaea anthocyanin nanocomplexes and the application in shrimp preservation

In this experiment, the nanocomposite film prepared by adding of nanocomplexes (ACNs-CHC/CMC-WPI) of Vaccinium vitis-idaea anthocyanins encapsulated with carboxymethyl chitosan (CMC), chitosan hydrochloride (CHC), and whey protein isolate (WPI) to chitosan/corn starch (CTS/Corn) blend matrix for food packaging. The functionality and stability of anthocyanin-loaded nanocomplexes and anthocyanin-containing films were determined and compared. Good encapsulation was observed by transmission electron microscopy. The freshness preservation effect of the prepared films on shrimp was investigated. Scanning electron microscopy results showed that ACNs-CHC/CMC-WPI was uniformly dispersed in chitosan-corn starch matrix, indicating the formation of a stable CTS/Corn-anthocyanin nanocomplex film (CTS/Corn-AN film). Although CTS/Corn-free anthocyanin (CTS/Corn-FA film) had better antioxidant activity in the short term, the CTS/Corn-AN film could better maintain the antioxidant activity and original color after 28 days of light exposure. In summary, the CTS/Corn-AN film possessed better mechanical property with elongation at break at 88.67 %, oxidation resistance with DPPH scavenging of 28.71 % at 28th, and other physicochemical properties than those of the CTS/ Corn-FA film. Finally, the CTS/Corn-AN film showed effective freshness preservation of shrimp at 4 degrees C for 10 days compared to the control group due to durable antibacterial and antioxidant properties. Therefore, CTS/ Corn-AN film was promising active packaging material in shrimp preservation.