Abstract:

In order to ensure the quality of yellowfin tuna chunk after thawing, different thawing methods including air thawing at normal temperature, cold-storage thawing, warm salt-water thawing and static water thawing were used to explore their effect on the quality of yellowfin tuna chunk. Required times for thawing yellowfin tuna chunk by different methods and the changes in color, shearing force, pH, total bacterial count and sensory quality within 72 h after thawing were evaluated to address the relationships between thawing methods and the quality of tuna. Among 5 thawing methods, tuna warm salt-water thawing provided the best tuna quality. After warm salt-water thawing, the a* value, shearing force and sensory evaluation scores of the tuna were 12.30, 342.48 g and 12.80, respectively and the total viable count (TVC) within 48 h of storage was below the industrial standard threshold. Meanwhile, the color change and shearing force demonstrated better characterization of tuna quality change.

Key words: tuna, thawing method, quality assessment