Enrich hazelnut oil with long-chain PUFAs.

Turkey produces about 580,000 tons of hazelnuts annually, which is approximately 80% of the world's hazelnut production. Hazelnut oil is a valuable product. It's rich in monounsaturated and polyunsaturated fatty acids, as well as in vitamin E and sterols.

Long-chain w3 fatty acids--eicosapantaenoic acid (EPA) and docosahexaenoic acid (DHA)--are essential for our growth and development. They may also play an important role in the prevention and treatment of cardiovascular diseases, inflammatory diseases, hypertension, diabetes and rheumatoid arthritis. Vegetable and seed oils can be enriched with essential fatty acids to create new nutraceuticals or novel products that give us specific health benefits and functionality.

In recent years, several studies have focused on the lipase-catalyzed enrichment of oils by some essential fatty acids. The objective of Turkish researchers was to use lipase to enrich hazelnut oil with long-chain omega-3 polyunsaturated fatty acids (PUFAs). The investigators used response surface methodology (RSM) to the determine the optimum conditions for enriching hazelnut oil by incorporating n-3 PUFAs that were sourced from menhaden oil. A structured lipid containing PUFA may be nutritionally more beneficial than unmodified hazelnut oil.

Hazelnut oil containing n-3 PUFAs was successfully produced. The effects of incubation time, temperature, substrate molar ratio and water content on the incorporation ratio were investigated as well. By evaluating response surface graphs, the researchers found that the optimal conditions for incorporating long-chain n3 PUFAs into hazelnut oil were: at 45 C to 60 C, giving 30 to 40 hours for reaction time, at a 1:1 to 2:1 (mol/mol) substrate molar ratio and with a water content of 3% to 5% (wt/wt).

Experiments conducted at optimized conditions predicted by the model obtained from RSM yielded structured lipids with 19.6% w3 PUFAs. This value agreed well with that predicted by the model.

Further information. Beraat Ozcelik, Food Engineering Department, Istanbul Technical University, Maslak, Istanbul 34469 Turkey; phone: [phone]; fax: [phone]; email: [e-mail].