THE EVALUATION OF FUNCTIONAL PROPERTIES OF FISH MEAL

The raw material freshness and drying methods are determining factors of fish meal quality. The aim of this experiment was to study the effect of the drying method and raw material freshness as for its functional properties in fish meal. Blue whiting, herring and capelin meals produced in commercial fish meal processing plants in Iceland were obtained. The samples were categorized (according to the freshness of raw fish and processing technique) into three grades (low temperature (LT), Norsea Mink (NSM) and standard). Freshness of raw material was assessed through the total volatile nitrogen content in fish before process. Fish meals were dried using air dryers (Dyno and Hetland) and steam dryers. Samples were tested for proximate composition, including salt content, unbound ammonia, water activity, bulk density, flow characteristics, particle size and some functional properties (viscosity, water holding capacity and solubility). Sub samples of all samples were stored at 35°C for four weeks and tested for moisture content, water activity and unbound ammonia content