Glass transition study of Nile Tilapia myofibrillar protein films plasticized by glycerin and water

Studies on glass transition of myofibrillar proteins based edible films are scarce. This work aimed to determine the T-g of edible films from Nile Tilapia myofibrillar proteins as a function of water content. Films with 30 or 70 g of glycerol/100 g of protein and several water content, were analyzed with a DSC TA 2010. Samples conditioned at water activity between 0.11 and 0.75, clearly showed one glass transition at low temperatures (<223 K), and another transition, less visible, above 273 K. DSC curves of samples conditioned at a(w)=0.84, also showed an endothermic peak below 273 K. These results rendered evidence of phase separation within edible films.