Properties of gelatin from the bone of Pacific cod (Gadus macrocephalus) as influenced by extraction temperature and time

Aquatic gelatin from the bones of Pacific cod was extracted using the distilled water at different temperatures (45 and 70℃) and times (4 and 8h) . The mixtures were then filtered and freeze-dried and four samples were obtained. The chemical composition and properties of the samples were characterized. Results revealed that with the rise of extraction temperatures and times, the gel strength and emulsifying properties decreased continuously, while the foaming capacities and turbidity increased. FTIR spectra exhibited the amide I absorption band of the 70℃ sample had the lower amplitude compared with that of 45℃ sample, which indicated the gelatins extracted at higher temperatures contained a lower degree of molecular order than those extracted at lower temperature.The gel matrix of gelatin prepared under higher temperature showed an irregular and disorder arrangement with lots of pore spaces.