Barrier and mechanical properties of starch/oil nanolaminated films

SLAVUTSKY, ANIBAL M.; BERTUZZI, MARÍA A.; ARMADA, MARGARITA

Foz do Iguaçu - Paraná

Congreso; IUFOST- Word Congress of Food Science and Technology; 2012

Edible films based on polysaccharides present suitable characteristics for food protection, but these properties are affected by the increase in the film water content. A nanolaminate consists of two or more layers of material with nanometer dimension that are physically or chemically bonded to each other. Several authors have used this technique in synthetic film, but have not been reported in edible films yet. In this work, starch film was prepared by casting. Nanolaminate was prepared by dipping the film in sunflower oil and subsequently rinsing with hexane. Scanning electronic microscopy shows the starch film coated with an oil nanolayer. The resulting film was characterized in terms of water vapor permeability with 100% of relative humidity gradient at 25ºC, sorption isotherm at 25°C and mechanical test at a relative humidity of 53%. The nanolayered film shows a decrease of 76% on water permeability. Sorption isotherm curve shows the same trend as starch film but with an important reduction in film water content through all range studied. Nanolaminate provides excellent protection to water vapour adsorption up to relative humidity of 55%. Nanolaminate film presents an increase of 300% in tensile strength and a decrease of 76% in elongation. Nanolaminates present highly functional properties and promising future applications on multilayer edible coatings with enhanced mass transfer and mechanical properties.