EFFECT OF SALT AND OZONIZED-SLURRY ICE ON THE QUALITY INDICES OF TIGER GROUPER (Epinephelus fuscoguttatus)

Abstract

Tiger grouper is a high value of live reef fsh, which mainly exported to Hong Kong, Japan and Singapore. This study was carried out to investigate the quality indices (microbial and chemical) of tiger grouper (Epinephalus fuscoguttatus) stored for 20 days in slurry ice treated with 0.1 mg ozone l-1 (O3) and 3.3% sodium chloride (NaCl). Slurry ice contains 60% ice and 40% water was used as control. All samples were analysed for total aerobic, psychrotrophic bacteria, total volatile based nitrogen (TVBN) and trimethylamine (TMA) at interval of 5 days during 20 days storage. The total bacteria count of tiger grouper treated in slurry ice with O3 (SI+O3) showed signifcantly (p<0.05) decreased to about 0.24 log units compared to controls. However, bacteria counts of tiger grouper treated in slurry ice with NaCl (SI+NaCl) were not signifcantly different from both the controls and SI+O 3 samples. Psychrotrophics bacteria counts were effectively reduced to 0.39 and 0.18 log units after treatment of SI+O 3 and SI+NaCl, respectively. TVBN and TMA contents during 20 days storage for all treatments did not exceed the acceptable limit of 35 mg N 100g-1 and 15 mg N 100g-1, respectively. No signifcant difference (p>0.05) was found between controls and treated samples for TVBN and TMA contents. The combination of the slurry ice and ozone may be recommended for chilling and storage of tiger grouper to improve its storage quality.