Post-mortem changes in three fresh water eels, Mastacembelus armatus, Macrognathus aculeatus and Mastacembelus pancalus during ice storage

Abstract

The progress of rigor-mortis and the post-mortem changes in three species of freshwater eelsduring storage at room temperature (30° to 35°C) and ice (0°C) were studied. Rigor-mortis in fish sample atroom temperature, started 1hr after spiking and it reached to a maximum of 76%, 57.14% and 100% within 4hrs after death in Mastacembelus armatus (Baim), Macrognathus aculeatus (Tara baim) and inMastacembelus pancalus (Guchi), respectively. In ice stored eels rigor also started within one hour of spikingand gradually reached to a maximum of 88.89% within 3 hrs in Baim and 85.71%, 100% in Tara baim and inGuchi respectively within 2 hrs. Rigor continued for 17, 14 and 18 hrs in Baim, Tara baim and Guchi,respectively and then started to relax. The pH of the muscle was 6.84, 6.80 and 6.92 immediately after catchin Baim, Tara baim and in Guchi, respectively which decreased gradually with the lapse of storage periodregardless of the storage temperature. The organoleptic quality of eels during ice storage was assessed on thebasis of sensory parameters. Baim was found in acceptable conditions for 24 days whereas Tara baim andGuchi were in acceptable condition for 28 days in ice storage. Percent moisture content increased but proteinand lipid contents decreased in almost all the fish samples with the lapse of storage period but a little changewas observed in ash content. The TVB-N, peroxide and NPN value remained within the recommended valueup to 24 days in Baim and 28 days in Tara baim and Guchi. The initial bacterial loads were 6.5×103,6.2×103 And 6.3×103 CFU/g in Baim, Tara baim and in Guchi, respectively. At the end of the 24 days ofice storage, bacterial load increased in all the fish samples.