Chitosan films activated with phytochemicals extracted from carrot by-product encapsulated in TPP chitosomes

The main objective of this study was to extract phytochemicals from carrot by-product, encapsulate them in TPP chitosomes (consisting of liposome vesicles coated with chitosan cross-linked with sodium tripolyphosphate) and incorporate them into chitosan (Ch) films. Physicochemical, antioxidant and antimicrobial properties of films were evaluated. Three concentrations of TPP chitosome suspension were studied: 50%, 60% and 70%, designated TPPCh50, TPPCh60 and TPPCh70 respectively. Microscopy analyses showed that the particles modified the surface and internal structures of the Ch films, providing films with higher average roughness (Control: 12.6 +/- 1.8 nm vs. TPPCh70: 96.1 +/- 8.0 nm) and decreased gloss (Control: 34.1 +/- 3.9 GU vs. TPPCh70: 5.6 +/- 1.0 GU). Furthermore, the TPPCh films displayed decreased Ch intermolecular interactions, which produced less mechanically resistant (TS = 15.3 MPa), more elongable (EB = 47.9%), slightly more water-soluble (SI = 14.7%) and more water-vapour permeable (WVP = 7.54*10(-9) g/msPa) films, mainly at high phytochemical concentration (TPPCh70) as compared to the Control. TPPCh addition in the Ch film improved its antioxidant capacity (3.6 times greater) and UV/Vis light barrier property, but no significant antimicrobial activity was observed. In conclusion, TPPCh films could be used as packaging to preserve foods that are sensitive to oxidation.