The following chemical changes were observed during the cold storage of mussels for 6 days at 4 degrees C. Total volatile basic nitrogen (TVB-N, mg N per 100 g) and trimethylamine values (TMA-N, mg N per 100 g) were increased from 22.55 and 5.96 mg per 100 g at day 0 to 12.38 and 0.42 mg per 100 g, respectively, at the end of the storage period. The indole value and putrescine concentration were increased from 15.36 mu g kg(-1) and 24.7mg kg(-1) to 34.46 mu g kg(-1) and 63.86 mg kg(-1), respectively, on the fourth day of storage. The pH was slightly reduced and tyramine and cadaverine were not detected during storage. TVB-N, TMA-N and indole value could be selected as decomposition indicators for mussels during their cold storage. Acceptable limits of 15 mg per 100 g for TVB-N, 3 mg per 100 g for TMA-N, 35 mu g kg(-1) for indole and 60 mg kg(-1) for putrescine are suggested. Sensory and chemical results indicated that the shelf-life of mussels at 4 degrees C is limited to 4 days. (c) 2005 Society of Chemical Industry.