Abbreviation for transmission electron microscopy — an imaging technique in which a beam of electrons transmitted through an ultrathin specimen reveals structure at nanometre resolution, far beyond light microscopy. TEM lets food scientists visualize the ultrastructure of emulsions, protein gels, starch granules, bacterial cells, and viruses, explaining texture, stability, and microbial behaviour at the molecular scale. Specimens require elaborate preparation — fixation, embedding, sectioning, and staining — which can introduce artefacts demanding expert interpretation. Though costly and slow, TEM remains unmatched for settling questions about what food structures truly look like.