Changes of Quality and Flavor Compounds in Alaska Pollock Fillet During Salting

Abstract

In order to explore the quality changes of Alaska pollock fillet during salting, the Alaska pollock fillet were selected as raw materials and the drying conditions of Alaska pollock fillet were as follows: The amount of salt added was 100% (w/w), salting time was 15 days, and salting temperature was 10 ℃. The effects of different salting time on the quality of Alaska pollock fillets were studied with TBA, nitrite, fatty acid, free amino acid, tissue structure and volatile flavor compounds as indicators. The results showed that the TBA value of Alaska pollock fillet increased from 0.14 mg/kg to 0.26 mg/kg, the final content of nitrite which showed a trend of first increased and then decreased was 2.91 mg/kg. The total amount of saturated fatty acids in Alaska pollock fillet was slightly increased, the contents of pentacenoic acid and oleic acid in monounsaturated fatty acids significantly increased (P<0.05), and the contents of DHA and EPA in polyunsaturated fatty acids significantly decreased (P<0.05). The content of free amino acid showed a trend of first decreased and then increased. The macromolecular proteins which molecular weight was 100~245 kDa were gradually degraded, the content of actin which molecular weight was 48 kDa gradually increased and the proteins which molecular weight was less than 20 kDa were partially degraded. The cross section of muscle fibers of Alaska pollock fillet became irregular, muscle fibers contracted obviously, and the intercellular space first became larger and then smaller. The fishy components of Alaska pollock fillet decreased, and the contents of esters and alcohols increased. During the salting process of Alaska pollock fillets, the TBA value and nitrite of Alaska pollock fillet were within safe limits, the lipid oxidation was mainly polyunsaturated fatty acid oxidation, some macromolecular proteins were gradually degraded, the total amount of free amino acids increased in the middle and later stages of salting, the muscle fiber shrinked, the fishy smell decreased, and the overall flavor of fish meat was improved.

Keywords

• salted
• alaska pollock fillet
• quality
• flavor
• safety