Influence of refining steps on trace allergenic protein content in sunflower oil

Background: Although allergy to sunflower seed and oil is a relatively rare occurrence, several cases of sunflower seed allergy have been observed, an d me have already described one case of anaphylaxis after eating sunflower oil and margarine. Objective: The aim of our study was to determine and characterize the aller gens from sunflower oil at the different steps of the refining process: cru de pressed oil (step A), acidification and neutralization (step B), pregumm ing by centrifugation (step C), washing (step D), bleaching (step E), gummi ng by filtration (step F), and deodorization (step G). Methods: A sample of oil from each step of the process (steps A to G) was h eat extracted with PBS, The protein concentration of each extract was evalu ated by using the micro-Bradford assay. Samples mere run on SDS-PACE, The i mmunoblot was performed with the serum of a patient sensitized to sunflower seed and oil. Results: The extracts obtained after each step reveal a decrease in total p rotein concentration from 13.6 mug/mL to 0.22 mug/mL. The result of SDS-PAG E shows 5 bands, from 67 kd to 145 kd, with the most abundant being the 67- kd protein, The amount of this protein decreases after each step of the pro cess, It is, however, still present in trace amounts in the refined oil. Th e 67-kd protein, which is mainly present in the crude oil and slightly in t he refined oil, has been shown to be allergenic. Conclusion: Because of the presence of allergenic proteins, refined sunflow er oil may pose a threat to people highly sensitized to sunflower seeds.