2-Thiobarbituric acid (TBA) is an index of lipid oxidation.
Changes in TBA value are shown in Fig. 3. TBA value of the lot II fish
sample was significant higher than the corresponding value of the
lot I sample during the frozen storage. This observation was indicative
of the fact that chitosan clearly inhibited lipid oxidation in
fish flesh. According to Connell (1990), TBA values of 1–2 mg
MDA/kg of fish flesh are usually regarded as the limit beyond
which fish will normally develop an objectionable odour. In this
study, the initial TBA value of the lot II fish sample was 0.38 mg
MDA/kg and this value increased to 1.41 mg MDA/kg after 10 days
of the storage period. After 15 days, this value reached 2.32 mg
MDA/kg, which exceeded the maximal permissible limit of 2 mg
MDA/kg in the fish muscle. However, the final TBA value of lot I,
which was within the limit value, was 0.83 mg MDA/kg after 30
days of frozen storage. The data revealed that the lot I sample,
which was dipped with chitosan, indicated preservation of fish
flesh by inhibiting the oxidation of lipid