Safety evaluation of salmon muscle consumption in patients with salmon roe allergy

The β′-component, a major allergen found in fish roe, is synthesized in the liver of female fish as part of the precursor of the egg yolk protein vitellogenin (Vg). Vg is distributed through the bloodstream and contributes to ovary development. In the present study, β′-component, present in Vg fragments, was detected in the muscles and internal organs of mature female salmon, with concentrations exceeding the recommended labeling level under Japan's food allergy labeling system. Additionally, total protein extracted from tissues of female salmon reacted with immunoglobulin E antibody against the salmon roe β′-component. No β′-component was detected in the tissues of mature male fish in the absence of sex hormone stimulation from females nor in immature salmon without sexual differentiation, but excess stimulation of the female sex hormone induced Vg synthesis containing the β′-component in the male fish. These findings suggest that taking into account fish sex, maturity, and sexual isolation of mature male fish could improve the safety of salmon meat for individuals with salmon roe allergy.