Survey on qualitative changes of minced Silver carp stored at superchilling in Modified Atmosphere and typical packaging

In this research qualitative changes of minced fish were examined in Modified atmosphere (50: 5: 45 for N2: O2: CO2 gases) and Typical packaging stored at supercoiling (-2oC) temperatures, the results showed that the trend of total volatile basic nitrogen change (TVB-N mg / 100 g) by using superchilling method in the modified atmosphere packaging reduced the formation of TVB-N and the increase of this index was significant in typical packaging (P <0.05). The amount of reactive substances with Thiobarbituric acid (TBARS / mg MDA/kg) in typical packaging peaked over than permissible range and reached to 2/27±0/05 mg after 35 days, Whereas the TBARS index was significantly lower in modified atmosphere packaging (P<0.05). The pH changes in treatments were descending and the same, during the evaluation. Entirely there was a significant increase in TBARS and TVB-N in typical packaging samples compared to modified atmosphere packaging. This indicates that fat oxidation during storage in typical packaging due to oxygen penetration into the package and the activity of the oxidative and enzymatic mechanism during storage. In sensory assessments, modified atmosphere packaging treatment obtained a significantly higher quality score in color, odour and texture (P <0.05). This result can be attributed to the effect of modified atmospheric packaging treatment on decreasing or stopping of biochemical activity. Totally, the modified atmosphere packaging as a selective treatment, increase shelf life for five days.