Preparation of biopolymer film from chitosan modified with lipid fraction

Films formed from polysaccharides, as chitosan, present a high permeability in water vapour. In order to increase resistance to water vapour for chitosan‐based films, different lipid fractions were incorporated into a filmogenic matrix: fish and vegetable oils, stearic and oleic acids. The chitosan showed a molecular weight of 150 kDa and a deacetylation degree of 86 ± 1%. Results showed that incorporation of different lipid fractions decreased the water vapour permeability (WVP) (1.3–1.8 g mm m^?2 day^?1 kPa^?1) as compared with pure chitosan film (3.8 g mm m^?2 day^?1 kPa^?1). A higher reduction in WVP (65%) was found with the addition of refined fish oil to the continuous matrix of the films than with the addition of refined rice oil, oleic or stearic acid (50–60%). However, pure chitosan films showed better tensile strength (TS = 33 MPa) and elongation percentage (E = 18%) than lipids fraction–chitosan films (7–19 MPa and 7–13%, respectively).