ARS | Publication request: Use of polyunsaturated fatty acids with tocopherol in poultry feeds

Submitted to: Lipids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 30, 2010
Publication Date: N/A

Interpretive Summary: Docosahexaenoic acid (DHA) is a polyunsaturated fatty acid that can improve nervous system development and function. It is used in animal feeds and functional foods to impart health benefits. However, DHA is degraded at elevated temperatures and loses bioactivity. Vitamin E (a-tocopherol), a natural antioxidant, was combined with DHA to prevent such oxidative degradation. Vitamin E was shown to effectively reduce the amount of DHA degradation when added at low levels. These results will promote the use of DHA in formulations subjected to elevated temperatures during production.

Technical Abstract: The ability of a-tocopherol to prevent the degradation docosahexaenoic acid (DHA) at elevated temperatures was investigated in a series of laboratory experiments. DHA is known to promote nervous system function and health, however, DHA and similar highly unsaturated compounds are readily oxidized with structural degradation and loss of bioactivity. Mixtures of DHA and a-tocopherol were prepared and incubated at 70°C and 120°C. Samples were taken periodically and analyzed by gas chromatography to determine the amount of DHA remaining. Results showed 80% of the initial DHA remained after 72 hours at 70°C when a-tocopherol was present at 0.25 mg/mg DHA compared to 43% without a-tocopherol. When a-tocopherol was increased to 2.5 mg/mg DHA the amount of DHA decreased to 62%. A similar trend was observed at 120°C. These data suggest an intermediate amount of a-tocopherol is optimal when formulating pelleted feeds with DHA.