Characterization of gelatins extracted from saltwater fish skins

3rd International Conference WASTES: Solutions, Treatments and Opportunities, 14th to 16th September 2015, Viana do Castelo, PortugalThis research work aimed at characterizing gelatins obtained from three saltwater fish skins, namely, yellowfin tuna (Thunnus albacares), blue shark (Prionace glauca) and Greenland halibut (Reinhardtius hippoglossoides), dried at either 45 and/or 80 ºC. Rheology and textural analyses were performed in order to assess differences in physical properties of the resulting gelatins. Differences between fish species were registered, with gelatins extracted from yellowfin tuna skins showing overall less variation between gelatins than the ones obtained from blue shark skins. As extraction temperature is concerned, differences were also reported among gelatins, with an increase in such temperature being translated into a decrease in both melting and gelling temperatures, and in bloom values. Gelatins extracted at 45 ºC showed more physical resilience. Gelatin from Greenland halibut skin was the softest gelatin, presenting slow transitions between solid and liquid phases. Gelatins physical properties depend on both the fish species and temperatures utilized in the production processesN