Investigation of viscosity and gelation properties of different mammalian and fish gelatins

Abstract

An easy-to-use method has been established to investigate important process parameters of gelatin solutions: viscosity, gelation temperature and gelation process. The measurement of these parameters is exemplified on several mammalian gelatins and is used to investigate the differences between mammalian and fish gelatins in solution. Hydrodynamic radii have been determined in addition by photon correlation spectroscopy. A series of mammalian gelatins of different Bloom numbers (from hydrolyzed to Bloom 300 gelatins) has been investigated. Gelation temperature, solution viscosity and hydrodynamic radius increase with increasing Bloom number. The activation energy of the gelation process is found to decrease with increasing Bloom number. Three fish gelatin samples have been investigated by the same technique. The fish gelatins show rather low gelation temperature, but relatively high solution viscosities. They do not correlate with any of the investigated mammalian gelatins. These fish gelatins therefore provide a type of gelatin with different technological properties compared to the mammalian gelatins. This could enlarge the already broad field of gelatin applications even further. The fish gelatins can find use in applications where high solution viscosity without gel formation is desired.