Quality changes in skipjack tuna (Katsuwonus pelamis) after delayed icing and subsequent storage in ice (0-2 deg C)
1994
Djauli, N. (Philippines Univ. in the Visayas, Leganes, Iloilo (Philippines). Coll. of Fisheries)
Sensory evaluation showed that the shelf-life of skipjack tuna was 16.9 hours at ambient temperature, 18.7 days when iced immediately, and 11.2, 7.06, or 4.9 days, with a 5-, 10- or 15 hour delay, respectively. Shelf-life of skipjack tuna in the ice was reduced by approximately one day for every hour delay in icing. Nucleotide decomposition expressed as percent K-value was 60.6 to 79.5 percent at rejection levels. However, hypoxanthine values were found to be low (0.17 to 0.22 micromole/g). Total volatile nitrogen (TVN) values of fish held at ambient temperature increased progressively, reaching values of 39.1 mg/100 g at rejection point. In contrast, TVN values during storage in ice were found to be fluctuating. Both hypoxanthine and TVN were unreliable as quality indices for this species stored in ice at 0-2 deg C. Total viable count (TVC) increased progressively reaching counts of 106 to 107 cfu/g at rejection point for fish held at ambient temperature, and 107 to 108 cfu/g for fish stored in ice, respectively. H2S producer count at ambient temperature was found to be low (103-104 cfu/g). However, during storage in ice, H2S producer count increased progressively, reaching 105 to 107 at rejection point. Histamine in both white and dark meat increased with storage time. When it was rejected, histamine content was 5.87 to 7.36 mg percent and 5.97 to 7.37 mg percent for white and dark meat, respectively. White meat contained higher histamine level than did dark meat at the final stages of the study
显示更多 [+] 显示较少 [-]