Storage of dried fish skins on quality characteristics of extracted gelatin

Drying was evaluated as preservation method for storage of Dover sole (Solea vulgaris) skins. Fish skins were air-dried by using ethanol, ethanol-glycerol mixture and marine salt, and stored at room temperature for 160 days. Gelatin extraction was carried out periodically during the storage time, and the quality of the resulting gelatin preparations was evaluated according to the molecular weight distribution, viscoelastic properties, gelling and melting temperatures and gel strength. All the drying methods used showed a similar effect on the gelatin quality characteristics evaluated. Although drying involved a slight decrease in viscoelastic properties as well as gelling and melting points, it was striking the great protein stability found throughout the storage period. Drying scarcely affected gel strength, which values did not show noticeable changes along the storage.