Oleosins are a family of plant proteins that associate tightly with oil bodies—lipid droplets that store fats in seeds. Biochemically they are small, amphipathic proteins that embed into the oil-body surface, helping preserve oil stability when seeds dry and during germination. Oleosin Variant B refers to a specific isoform or peptide fragment within that family often studied in seed crops such as peanut, soybean, and sunflower. Interest in oleosins grew from plant biology and food science research; more recently they have been evaluated in immunology studies because they can persist through processing and sometimes elicit antibody responses. As structural lipid-droplet proteins, oleosins serve a clear biological role in seed physiology while also representing antigenic targets when the immune system encounters seed-derived foods or extracts.

Elevated IgA or IgG reactivity to Oleosin Variant B may indicate prior exposure and immune recognition of that seed protein. IgA-dominant responses are often linked to mucosal exposure in the gut, while IgG responses reflect systemic immune memory or circulating antibody levels; patterns across both isotypes provide more nuance than a single measure. Low or undetectable reactivity suggests no measurable antibody response to this specific oleosin variant, but it does not rule out sensitivity to other seed proteins, peptides, or food components. Interpretation should always consider the full Food Zoomer profile and clinical context, including other related markers and symptom patterns.

Oleosin Variant B is included to detect immune responses to seed oil-body proteins that can be missed by whole-extract testing. Evaluating this marker at the peptide level improves specificity within seed and legume domains, helping providers identify clustered reactivity and refine dietary strategies based on immune patterning.