There is an increasing interest in the utilization of giant squid (Dosidicus gigas) fishery,whereas the potential edibleness of this kind of squid could be restricted due to its off-flavors,especially the unfavorable sour taste,detected by consumers.The objective of this work was therefore to explore the key taste-active compounds present in giant squid mantle muscle and their sensory contribution.Potential taste-active components of Dosidicus gigas mantle muscle were investigated firstly and then their taste contribution was rated on the basis of Dose-over-Threshold (DoT) factors.Taste reconstitution experiments were performed indicating that complete synthetic extract containing 44 components of Dosidicus gigas mantle muscle almost reproduce the taste profile of authentic muscle extract.Taste omission tests demonstrated that 16 compounds are the key contributors to the taste profile and acid opines(meso-alanopine,β-alanopine,tauropine)exerted larger impact on sourness than organic acids did.Furthermore,it was the first time to describe acidic opines as essential taste contributors to the sourness of Dosidicus gigas mantle muscle.