Structural basis of tropomyosin stability and processing-dependent allergenicity in edible insects

ABSTRACT Edible insects are increasingly considered promising sustainable protein ingredients in future food systems, but allergen safety remains a major barrier to their wider use. Tropomyosin (TM), a conserved α-helical coiled-coil protein, is one of the most important pan-allergens shared by insects, crustaceans, mites, and other arthropods. This review examines insect TM as a structure-driven food safety challenge by linking its molecular organization, extraction behavior, analytical detectability, and processing responses. The coiled-coil structure and actin association contribute to TM stability during conventional processing, while structural persistence or reversible unfolding can preserve IgE-binding epitopes despite changes in solubility and analytical detectability. Available studies suggest that boiling and other mild thermal treatments mainly alter TM solubility and aggregation. In contrast, enzymatic hydrolysis and severe combined treatments show greater potential to reduce immunoreactivity, although outcomes remain species- and matrix-dependent. Importantly, reduced TM detection after processing does not necessarily indicate allergen elimination, as changes in band intensity or antibody signal may reflect altered extractability, aggregation, or changes in epitope accessibility. Future work should therefore combine TM-specific proteomics, epitope-level characterization, and clinically relevant validation to determine whether processing truly reduces allergenic risk. A clearer understanding of TM stability and processing responses will support safer use of insect-derived proteins in future food applications.