Mechanical Properties of Heat‐cured Whey Protein‐based Edible Films Compared with Collagen Casings under Sausage Manufacturing Conditions

Edible films were produced using whey protein isolate (WPI) (5%, w/v), glycerol (3.3%, w/v) and candelilla wax (0.8%, w/v). One set of films was heat cured at 90°C for 12 h and another at 80°C for 24 h. WPI‐based films, together with collagen films, were put through a meat‐processing scheme typical of Polish sausage manufacture. Meat‐processing conditions were stage 1: 57°C/60 min/36% RH; stage 2: 65°C/90 min/60% RH; and stage 3: 77°C/30 min/80% RH. Effects of meat‐processing conditions on mechanical properties: tensile strength (TS), elongation (%E), and apparent modulus (AM) were determined. All films remained intact throughout the process. TS, %E, and AM of collagen films did not change during the multistage cooking process. The %E of heat‐cured WPI films was similar to that of collagen films and also did not change during the cooking stages. The TS and AM of both heat‐cured WPI‐based films were initially lower than collagen films and continued to decline during the cooking stages. TS and AM of both films at the end of cooking were lower (P < 0.05) than films that did not go through the multistage cooking process.