Optimization and characterization of biodegradable films from chicken gelatin crosslinked with oxidized phenolic compounds

Chicken gelatin derived from poultry by-product was combined with caffeic acid (CA), rutin (RUT) and glycerol (GLY) to obtain biodegradable films. Optimum cross-linking conditions were investigated using Response Surface Methodology (RSM). The results showed that cross-linking led to lower L* value and higher b*, and the higher opacity values in the films. Water solubility (WS) decreased up to 50% after the incorporation of 1.25% CA compared to the commercial gelatin (cattle and pig based) films. Crosslinking improved the thermal stability and the tensile strength (TS) of films. Optimized cross-linking combination was determined as 0.96-1.56% CA, 0-1.25% RUT, and 29.5-30.5% GLY. Overall, this study demonstrated that crosslinking by CA and RUT can be used to improve the physical and barrier properties of gelatin films having excellent potential for the development of biodegradable films for packaging uses. These films may also result in an improvement and added value in poultry by-products.