Analytic investigations on protein content in refined seed oils: Implications in food allergy

BackgroundA number of scientific reports have investigated the possible implications of refined seed oils in allergic reactions, resulting in conflicting points of view. Also the total amount of residual proteins after refinement is still a matter of debate. Nevertheless, seed oils are now blamed as possible cause of allergic reactions.ObjectiveTo determine the true amount of proteins after oil refinement and to shed new lights on allergenic properties of refined seed oils.MethodsWe optimized a protein extraction procedure on several commercial refined seed oils. Both colorimetric and amino acid analysis were used to measure residual protein content. SDS–PAGE was also used for characterizations of protein band patterns. Sensitized child patients sera were tested by Western blot on PAGE-resolved proteins.ResultsOur extraction method proved to be effective and reproducible. Amino acid analysis resulted more accurate in determining the protein content with respect to colorimetric methods, indicating a higher protein content than that previously reported. IgE responsive residual proteins were found in peanut oil extracts.ConclusionsOur preliminary data suggest that fully refined seed oils should be taken into account in the context of allergic reactions and would benefit of further toxicological studies.