Effect of Protein Variety on Properties of Gelatin Edible Films

Influences of whey protein isolate (WPI), sodium caseinate (NaCas) and soybean protein isolate (SPI) on gelatin (GA) film properties were investigated by comparing with common plastic films. The results suggested that WPI and NaCas caused tensile strength (TS) of GA film increasing from 6.38MPa to 7.17MPa,7.52MPa; water vapor permeability (WVP) decreasing from 18.46*10-13g m-1 s-1 Pa-1 to 17.92*10-13g m-1 s-1,16.46*10-13g m-1 s-1; and resulted in oxygen transmission rate (O2TR) decreasing from 128.315cm3m-2d-10.1MPa-1 to 37.352 cm3m-2d-10.1MPa-1, 38.129 cm3m-2d-10.1MPa-1.WVP of GA films increased 13.2% and O2TR decreased 4.1% as the addition of SPI. NaCas-GA composite films was the optimal group which had significant advantage on Ts, optical properties and barrier properties.