PHYSICAL, MECHANICAL, SURFACE, AND STRUCTURAL PROPERTIES OF SODIUMCASEINATE AND SOY PROTEIN ISOLATE SINGLE AND COMPOSITE PROTEINCOMPOSITE EDIBLE FILMS

Edible coatings are an alternative to decrease the use of one-use synthetic materials, since they can extend food stability by controlling moisture exchange.In this research the physical, mechanical, surface and structural properties of soy protein isolate or sodium caseinate edible films, and their composite combinations (mixture and bilayer), were investigated.Composite films were thicker, but with less soluble matter, and higher WVP values.Bilayer and mixture samples were harder and less stretchable.Soy protein isolate and mixture samples presented higher roughness, and bilayer samples presented a flat surface.The structural analysis by FTIR and DSC presented an inherent interaction between the employed proteins, resulting in a heterogenic and thermally compatible structure that changes physical that modifies the single proteins edible film properties.