Edible Films Based on Tapioca Starch and WPC or Gelatine Plasticized with Glycerol: Potential Food Applications Based on Their Mechanical and Heat-Sealing Properties

Abstract

For the last decades, the food industry has been searching for cleaner alternatives to petroleum-derived plastics to ensure food safety, such as edible films. Although tapioca starch and proteins have good film-forming abilities separately, the combination of both may enhance their properties. This study aims to investigate the effect of the combination of three concentrations (80:20 w/w, 70:30 w/w, and 60:40 w/w) of tapioca starch and protein (porcine gelatine or whey protein concentrate) and three concentrations of glycerol (2% w/w, 2.5% w/w, and 3% w/w) on the mechanical and thermo-sealing properties of edible films. Tensile strength, deformation at break, firmness, Young’s modulus, heat-sealing capacity, and the necessary energy to cause an adhesive failure were studied. Results showed that the different combinations of starch, glycerol, and proteins allow the formation of materials with a wide range of characteristics. All the tested films showed potential to be used as food containers, those obtained from tapioca starch and gelatin were stronger, firmer, and less deformable than tapioca starch: whey protein films. More studies should be carried out in order to determine their application, such as water affinity, compatibility with food matrices or other substances, and microbiological stability.