On the other hand, after six hours of storage, negative control incubated at 28 °C (A0B1) showed decrease in freshness, with TVB number peaked at 30 mg N %. The sharp increase was possibly caused by the autolysis process and bacterial activity during the storage period. Despite the evisceration phase prior to storage, the bacteria existing internally and externally worked actively to convert the existing protein and/or its derivative compounds in the samples’ flesh tissues into volatile bases such as ammoniac, histamine, hydrogen sulfide (H2S) and trimetilamine (Karungi et al. 2003) which produced the rotten-egg-like odor. The TVB number was decreased at 12 h of storage and stabilized at 26 mg N % 6 h after. This activity was confirmed by the TPC result and the organoleptic assessment (cf. section 3.2 and 3.3), where the bacterial total number reached 7.9 × 105 CFU · g–1 at 6 h of storage and organoleptic assessment indicated changes in samples appearance in all four parameters (eyes, flesh, texture and odor) below the acceptable limit (7). The sample without nano-chitosan treatment stored at 4 °C (A0B0) had TVB number that started to increase only after 12 h of storage, but did not trespass the freshness threshold. The overall TVB data indicated that fish sample immersed in WW based 1 % nano-chitosan and stored at 4 °C (A2B0) gave the optimal result, with TVB number only as high as 19 mg N % during the experiment.