“…The edible films were prepared by the solution casting method [ 29 , 30 , 31 ]. Briefly, gelatin, pullulan, sodium alginate and sodium tripolyphosphate were dissolved in distilled water at 50–60 °C, respectively, where sodium tripolyphosphate can be used as a moisture-retaining agent [ 32 , 33 , 34 ] and also as a cross-linking agent to enhance protein cross-linking [ 35 , 36 , 37 , 38 ]. Glycerol was added as a plasticizer.…”