Value-adding to australian marine oils

Abstract

Marine biotechnology in Australia is a relatively new field. Australia has one of the largest exclusive economic zones (EEZ) globally, an area known to be rich in marine biodiversity from polar, temperate and tropical waters. It has been acknowledged for some time that although Australia is surrounded by a rich marine resource, we are not taking advantage of the potential benefits from the abundant biodiversity. Future research efforts will address this shortcoming. An overview on aspects of current Australian research and development in marine biotechnology, focusing on marine omega-3 oils, will be presented. A comprehensive data-base has been established on the nutritional composition (oils emphasis) of principal Australian seafood. Results are available for strategic marketing of Australian fish species as well as for use by medical and consumer groups. Most Australian fish contain high levels of the nutritionally important omega-3 polyunsaturated fatty acids (PUFA) - eicosapentaenoic acid (EPA, 20:5ω3) and docosahexaenoic acid (DHA, 22:6ω3). Australian fish generally have higher relative levels of DHA compared to fish and oils from northern hemisphere waters. Tuna are a particularly good source of DHA-rich oil, with the manufacture of Australian-made, value-added tuna oil products commenced in 1998. The tuna oil products contain in excess of 25% DHA, a DHA to EPA ratio of >3, and a lower proportion of cholesterol than is found in flesh from tuna and some other seafood. Species specific differences and regional variation in lipid and fatty acid profiles of seafood highlight the ecological significance of this class of biochemical compounds; in addition changes in oil profiles with cooking and aquaculture are examined. Microbial sources of PUFA have also been developed, with a range of applications possible. Lipid class profiles of wax ester rich oil fishes enabled a species associated with consumer illness to be identified.