Surface Morphology of Chitosan Films with Incorporation of Grape Pomace

The use of edible films and coatings in food protection and preservation from renewable biopolymers has recently increased due to its nontoxicity, biocompatibility, and antimicrobial properties. Further, edible films can be an efficient vehicle for incorporating functional compounds, which improve its characteristics [1]. Grape pomace consisting of skins, seeds, and stems, is a rich source of phenolic compounds, lipids, polysaccharides and proteins. Since grape pomace is an abundant by-product, there is a high interest to use its extracts in order to improve the chitosan films properties. This work consists in the preparation of chitosan-based films with improved properties for food applications. Three grape pomace fractions are incorporated: 1) hot water extract (HWE), with 72 % polysaccharides; 2) chloroform extract, rich in waxes (W); and 3) n-hexane extract, with the oil (Oil), comprising 70 % linoleic acid. As control, a film only with chitosan (Ch) is also prepared. The study of the films morphology, mainly with incorporation of natural extracts, is important since there is a direct correlation between morphological properties and mechanical and permeability behaviour of the films [2]. Then, tapping mode Atomic Force Microscopy (AFM) is used to observe the surface characteristics of the films with grape pomace fractions incorporation and control.