Characterisation of processing wastes of Atlantic Salmon (Salmo salar) and Yellowtail Kingfish (Seriola lalandi) harvested in Australia

Atlantic Salmon (AS) and Yellowtail Kingfish (YTK) are two major commercial fish species in Australia. During food processing, waste material of 40-50% of the whole AS and YTK is generated, including the head, skin, frame, belly flap and viscera. This material is usually discarded even though it is rich in protein and fat. The aim of this study was to characterise the composition of these wastes for their potential applications. The contents of protein and fat in these wastes are 10-20% and 20-30%, respectively. Profiles of amino acids, fatty acids and minerals showed they are good sources of essential amino acids (20-30% of total amino acids), omega-3 fatty acids (about 20% of total fatty acids) and various elements. For example, AS viscera is high in zinc (740mgkg^-1). Molecular weight distribution of the protein was mainly between 25 and 250kDa. The potential commercial applications of these wastes are discussed on the basis of these analyses.