Effects of combined antioxidants and packing on lipid oxidation of salted dried snakehead fish (Channa striata) during refrigerated storage

The objectives of this study were to determine the effects of combined antioxidants (Propyl gallate (PG) and sodium ascorbate) and packing on lipid oxidation in salted dried snakehead fish during storage at refrigerated temperature (4oC). The magnitude of oxidative changes was monitored by peroxide values (PV), thiobarbituric acid reactive substances (TBARS) values, moisture contents, water activity (Aw), color values (L*, a*, b*) and fatty acid composition. The results showed that the moisture content and Aw remained unchanged in all samples during storage. Changes in a* values of salted dried snakehead fish significantly decreased (P < 0.05) in all samples. However, salted dried fish using a combined 100 ppm PG and 100 ppm sodium ascorbate had significantly higher (P < 0.05) a* values compared to the other samples. The PV and TBARS values of the treatment without PG and sodium ascorbate increased, while they remained unchanged when using of 100 ppm PG and 100 ppm and sodium ascorbate and packed under vacuum. Total polyenoic acids in the PG and ascorbate mixed-treated decreased at a slower rate than those in the other treatments. The most effective method in controlling of lipid oxidation was vacuum-packing. A combination of PG and sodium ascorbate were effective in delaying lipid oxidation and showed a greater antioxidant activity in terms of the lower PV and TBARS values than did not with antioxidants