Fatty acids and their sucrose esters affect the properties of fish skin gelatin-based film

Abstract

The effects of fatty acids (FA) [palmitic acid (PA) and stearic acid (SA)] and their sucrose esters (FASE) on the mechanical properties, water vapor permeability (WVP), light transmission, and color of films from bigeye snapper and brownstripe red snapper skin gelatins were investigated. Tensile strength (TS) of films generally decreased with the addition of FA (p<0.05), while gradually increased with increasing FASE amount (p<0.05). WVP of films generally decreased with increasing amount of FA or FASE (p<0.05). However, films containing FASE exhibited the superior WVP barrier property to those added with FA. Marked increase in elongation at break (EAB) was observed when either FA or FASE at a level of 25% substitution was incorporated. Light transmission of films in both UV (200–280 nm) and visible ranges (350–800 nm) decreased with increasing FA amount. Films added with FASE were generally more transparent than those with FA. Chain length of FA or FASE affected the properties of films differently, depending upon gelatin sources. Therefore, the properties of fish skin gelatin-based films, especially water vapor barrier, could be improved by the addition of FA or FASE.