Rheological behaviour of some collagen extracts

Collagen extracts such as hydrogel, gelatin and hydrolysate were obtained from bovine hide. They were characterized by physical-chemical properties such as dry substance, total nitrogen, ash, fat, proteic substance (calculated from nitrogen content) and pH. Then, the analysed collagen extracts were adjusted at 1% collagen, pH 7.4 in order to be used as main components in drug delivery systems. The rheological properties of collagen hydrogel, gelatin and hydrolysate were determined and the following rheological models were established: Ostwald-de Waele for hydrolysate and gelatin and Herschel-Bulkley for hydrogel.