Biodegradable pressure sensitive adhesives produced from vital wheat gluten: Effect of glycerol as plasticizer A Physicochemical and engineering aspects

This work aimed at evaluating the influence of glycerol concentration and storage relative humidity (RH) on gluten-based adhesive properties. Adhesive aging and adhesive application over different food substrates were also evaluated. For such purpose, three adhesive formulations were developed from different gluten:glycerol ratios (1:0.6, 1:1, and 1:1.4), which were applied over a pectin-based film as support material. The adhesives presented better adhesion and cohesion properties when stored at 58% RH. The formulation with the best adhesive properties was the 1:1 gluten:glycerol ratio. The degradation of the adhesives during aging was considered small in the first thirty days. The adhesives presented potential to be applied on food grade materials with low hydrophilicity.