Microencapsulated fish oil powder from purified red salmon oil.

Fatty fish like mackerel, lake trout, herring, sardines, albacore tuna and salmon are high in two kinds of omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). As you know, omega-3 fatty acids benefit our heart and cardiovascular health.

It's possible to harness the healthful properties of salmon oil by purifying it and making human-grade microencapsulated salmon oil powder. Toward this end, researchers at Louisiana State University developed a microencapsulated salmon oil powder from purified red salmon oil. They demonstrated that such a powder will provide potentially beneficial opportunities for the further utilization of salmon oil.

In tests, the investigators extracted unrefined salmon oil from red salmon fish heads, then purified the oil. The purification technique involved using 5% shrimp chitosan, with an 83.3% degree of deacetylation, in a batch absorption process at 23 C for 60 minutes to remove moisture, insoluble impurities and minerals. The purified salmon oil was evaluated for its fatty acid profile, vitamin E, moisture content, insoluble impurities and minerals. A stable emulsion was prepared using the purified oil, sodium caseinate and lactose.

The investigators spray-dried the emulsion to produce microencapsulated salmon oil powder. The powder was evaluated for its fatty acid profile, moisture content and particle size. Testing was performed in triplicate, and data were statistically analyzed.

The researchers did not see any significant reduction of omega-3 fatty acids or vitamin E content of the oil during the purification process. The moisture content of unrefined salmon oil was reduced from 0.18% to 0.05%. After the adsorption process, the insoluble impurities in the unpurified oil decreased from 0.07% to 0.02%. The adsorption by chitosan significantly reduced the arsenic, mercury, iron and zinc content of the oil.

The resulting powder contained 40% red salmon oil, 18.4 mg of DHA per g of powder, 19.5 mg of EPA per g of powder and 41.3 mg of omega-3 fatty acids per g of powder. The particle diameter of the powder ranged from 5.5 [micro]m to 65 [micro]m.

Further information. Subramaniam Sathivel, Department of Food Science, Louisiana State University, 111 Food Science Building, Baton Rouge, LA 70803; phone: 225-578-0614; fax: 225-578-5300; email: ssathivel@agcenter.lsu.edu.