Modified atmosphere packaging of filleted rainbow trout

Shelf-lives of filleted rainbow trout (Oncorhynchus mykiss) packaged in over-wrap, vacuum and gas mixture conditions and stored at 1 +/- 1 degreesC were compared by measurement of pH, total volatile bases (TVB), hypoxanthine content, lipid oxidation (TBARS value), superficial counts of aerobic psychrotrophic flora and sensory analysis (colour, odour and flavour). The gas mixtures evaluated were 10% O-2 + 50% C)(2) + 40% N-2, 10% O-2 + 50% CO2 + 40% Ar, 20% O-2 + 50% CO2 30% N-2, 20% O-2 + 50% CO2 + 30% Ar, 30% O-2 - 50% CO2 + 20% N-2, and 30% O-2 + 50% CO2 + 20% Ar. Sensory quality deterioration was delayed and bacterial growth a; well as increases in pH, TVB and hypoxanthine levels were reduced by modified atmosphere packaging (MAP). Lipid oxidation was higher in gas packages with 20 and 30% O-2 than in those with 10% O-2. Vacuum-packed fillets presented the lowest TBARS values. In summary, MAP gave rise to a significant extension of shelf-life when compared with vacuum and over-wrap packaging. No significant differences were found between the packages containing either N2 or Ar. The best evaluated atmosphere consisted of 10% O-2 + 50% CO2 + 40% N-2/Ar. (C) 2002 Society of Chemical Industry.