Sugar ‘Fingerprints’ Offer New Route to Seafood Authentication

The global seafood market continues to grapple with persistent mislabelling and substitution, exposing consumers to health risks while undermining trust and sustainability efforts. Against this backdrop, new research from Singapore ¹ points to an emerging authentication approach based not on DNA, but on the structural signatures of naturally occurring sugars.

The study demonstrates that N-glycans – complex sugar molecules present in fish tissue – exhibit species-specific structural patterns that can be used to reliably differentiate between commercially important species such as barramundi, red snapper and tilapia, the latter frequently used as a lower-cost substitute. These glycan ‘fingerprints’ remain consistent even after processing, offering a practical basis for verification across the supply chain.

At the core of the method is liquid chromatography-ion mobility-mass spectrometry (LC-IM-MS), which enables detailed analysis of glycan structures. Crucially, certain glycans carry subtle modifications – notably O-acetylation – that result in molecules with identical chemical compositions but different three-dimensional structures. These structural variations prove highly specific to individual fish species, allowing clear differentiation based on their relative abundance and structural characteristics.