Chitosan-based Composite Films Research Articles

Effect of Chitin Nanofibrils on the Sorption Behavior of Chitosan-Based Composite Films

The effect of chitin nanofibrils on the sorption properties of composite films is studied. The value of sorption decreases with an increase in the content of chitin nanofibrils. It is assumed that the introduction of chitin nanofibrils into the chitosan matrix contributes to a denser packing of macromolecules, formation of a more ordered crystalline structure of the composite, and development of the liquid-crystalline-type mesophase. This assumption is verified by X-ray diffraction analysis.

Enhanced antimicrobial activities and physiochemical properties of edible film based on chitosan incorporated with Sonneratia caseolaris (L.) Engl. leaf extract

The purpose of this study is to prepare and characterize the potential edible packaging films based on chitosan and Sonneratia caseolaris (L.) Engl. leaf extract (SCELE) into matrix. The incorporation of SCELE into Chitosan matrix was conducted with various contents (1–3 % wt) and the chitosan-based film samples were investigated. The effects of SCELE on the physical properties and antimicrobial activity of samples were also characterized. The Vietnamese banana fruit was chosen for food preservation and the appearance of banana coated with and without chitosan-based composite films was evaluated. The results indicated that the presence of SCELE can improve the antimicrobial activities, water vapor barriers while a significant decrease in light transmittance was found. Furthermore, the tensile strength and thermal stability were not affected by the addition of 2 % wt SCELE. Bananas coated with composite film based on chitosan matrix and SCELE had longer life time than control sample and those coated with pure chitosan film, indicating that the combination of SCELE into chitosan matrix brings potential application for active edible food packaging.

Effect of the added polysaccharide on the release of thyme essential oil and structure properties of chitosan based film

Abstract In order to evaluate the effects of microbial polysaccharides and plant polysaccharides on the release of essential oil from chitosan-based composite films, the xanthan gum, pullulan, gum tragacanth and arabic gum were used to prepare the chitosan-thyme essential oil composite films. The results showed that the addition of four polysaccharides reduced the tensile strength and swelling degree, but increased the film solubility. The addition of arabic gum and pullulan delayed the release rate of essential oil from composite films in 95 % ethanol, but not in 50 % ethanol and distilled water. The film swelling was inconsistent with the release of essential oil in different food simulants. Chitosan-arabic gum composite films had better antifungal effect on the nectarine by the way of exposure of thymol released from the film. SEM analysis implied that four polysaccharides affected the microstructure of films. The release of essential oil could be regulated by the interaction between polysaccharides.

Interaction between water and the composite materials based on chitosan and chitin nanofibrils

Sorption experiments, X-ray structural analysis and NMR relaxation measurements were used in the study of peculiarities of interaction between water and chitosan-based composite films containing from 0.5 to 30 wt% of chitin nanofibrils. Comparison between dependences of amplitude of free induction decay signal, as well as spin-spin (spin-lattice) relaxation times on moisture content in samples led us to the conclusion that the composite films have more ordered supramolecular structure than pure chitosan films. It was demonstrated that the results of sorption and NMR relaxation experiments correlate well with the data of X-ray structural analysis.

Chitosan Nanocomposite Coatings for Food, Paints, and Water Treatment Applications

Worldwide, millions of tons of crustaceans are produced every year and consumed as protein-rich seafood. However, the shells of the crustaceans and other non-edible parts constituting about half of the body mass are usually discarded as waste. These discarded crustacean shells are a prominent source of polysaccharide (chitin) and protein. Chitosan is a de-acetylated form of chitin obtained from the crustacean waste that has attracted attention for applications in food, biomedical, and paint industries due to its characteristic properties, like solubility in weak acids, film-forming ability, pH-sensitivity, biodegradability, and biocompatibility. We present an overview of the application of chitosan in composite coatings for applications in food, paint, and water treatment. In the context of food industries, the main focus is on fabrication and application of chitosan-based composite films and coatings for prolonging the post-harvest life of fruits and vegetables, whereas anti-corrosion and self-healing properties are the main properties considered for antifouling applications in paints in this review.

Functional chitosan-based grapefruit seed extract composite films for applications in food packaging technology

Chitosan-based composite films with different amounts of grapefruit seed extract (GFSE) (0.5, 1.0 and 1.5% v/v) were fabricated via solution casting technique. Experimental results showed that GFSE was uniformly dispersed within all chitosan film matrices. The presence of GFSE made the films more amorphous and tensile strength decreased, while elongation at break values increased as GFSE content increased. Results from the measurement of light transmission revealed that increasing amounts of GFSE (from 0.5 to 1.5% v/v) did not affect transparency of the films. Furthermore, packaging of bread samples with chitosan-based GFSE composite films inhibited the proliferation of fungal growth as compared to control samples. Hence, chitosan-based GFSE composite films have the potential to be a useful material in the area of food technology.

Specific features of chitosan-montmorillonite interaction in an aqueous acid solution and properties of related composite films

The rheological properties of chitosan solutions in a 2% aqueous solution of acetic acid with added montmorillonite nanoparticles and the mechanical properties and structural organization of chitosan-based composite films are studied. The interaction between the polymer functional groups and surface charges of nanoplatelets is confirmed by conductometric and potentiometric measurements. With the use of a X-ray diffraction analysis, it is shown that the nanoparticles in films are in the exfoliated and intercalated states. The incorporation of up to 10 wt % modified montmorillonite nanoparticles into the chitosan matrix results in a successive increase in rigidity and a decrease in the elongation at break.