Effect of pH and Ionic Strength on Functional Properties of Fish Gelatin in Comparison to Mammalian Gelatin

Owing to socio-cultural and safety concerns, fish gelatin is considered to be a potential alternative to mammalian gelatin. The purpose of the current study was to investigate how functional properties of fish gelatin are influenced at different environmental conditions such as pH and NaCl concentrations. The functional properties of gelatin extracted from tiger-toothed croaker (TTC) (Otolithes ruber) and pink perch (PP) (Nemipterus japonicus) skin were examined at different pH (2-10) and salt (2 -10% of NaCl) concentrations in comparison to porcine (PG) and bovine gelatin (BG). Functional properties, in general, were found better in mammalian gelatin compared to fish gelatin in all the pH and ionic strength conditions. However, emulsifying capacity of TTC was found higher compared to PG, especially in acidic conditions. In acidic and high NaCl concentration (8-10%) conditions, the water holding capacity of both fish and mammalian gelatin was found similar. Though the fish gelatin showed lower bloom strength, it was found quite stable to variations in pH (2 - 10) compared to mammalian gelatin.