A study was made on the changes in Acid Value (AV) and Peroxide Value (POV) of the Mackerel ordinary muscle during low temperature storage. Three different samples were used-natural (control), ascorbic acid (As. A)-added and NaCl-added.
The samples were stored at the temperature of -15℃ during 75days immediately after quick freezing at -23℃ The change in the amount of fatty acids was also measured by means of GLC method.
1. In comparison with the control, the As. A added showed lower AV and POV, whereas the Nacl-added gave higher values.
2. Among the various fatty acids, which are constituents of the fish lipids, the amount of palmitic acid (16:0), stearic acid (18:0), and oleic acid (18:1) had been increased during the storage, while there had been steady decrease in the amounts of unsaturated fatty acid such as linolenic acid (18:3), arachidonic acid (20:4), clupanodonic acid (22:5), and docosahexaenoic acid (22:6).
3. For the first 30 days after freezing, the decreasing rates of the amounts of docosahexaenoic acid in three samples of the As. A-added, the control, and the NaCl-added-were 7%, 14% and 36% respectively. However, after 45 days these samples showed the same decreasing rates of more than 57 percent.
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