Properties and characteristics of nanocomposite films from tilapia skin gelatin incorporated with ethanolic extract from coconut husk.

Abstract

Impacts of ethanolic extract from coconut husk (EECH) at 0-0.4% (w/w, on protein basis) on properties of films from tilapia skin gelatin and gelatin/Cloisite Na(+) nanocomposite films were investigated. Young's Modulus, tensile strength and elongation at break of both films decreased with addition of EECH (P < 0.05). The lowest water vapour permeability (WVP) was obtained for gelatin film containing 0.05% EECH (w/w) (P < 0.05). Nevertheless, the nanocomposite film showed the lowest WVP when incorporated with 0.4% EECH (w/w) (P < 0.05). Generally, L*- value (lightness) decreased and a*- value (redness) of films increased (P < 0.05) with increasing levels of EECH, regardless of nanoclay incorporation. Transparency of both films generally decreased as the level of EECH increased (P < 0.05). Intercalated or exfoliated structure of nanocomposite films was revealed by wide angle X-ray diffraction (WAXD) analysis. Based on scanning electron microscopic (SEM) analysis, the rougher surface was found when EECH was added. EECH had varying impact on thermal stability of films as revealed by thermogravimetric (TGA) and differential scanning calorimetric (DSC) analyses. Thus, the incorporation of EECH determined the properties of both gelatin film and nanocomposite film in which the improved water vapour barrier property could be obtained.