15. Hypoxanthine Levels, Chemical Studies and Bacterial Flora of Alternate Frozen/Thawed Market-Simulated Marine Fish Species

  1. Rajeev Bhat2,
  2. Abd Karim Alias2 and
  3. Gopinadhan Paliyath3
  1. Olusegun A. Oyelese

Published Online: 16 JAN 2012

DOI: 10.1002/9781119962045.ch15

Progress in Food Preservation

Progress in Food Preservation

How to Cite

Oyelese, O. A. (2012) Hypoxanthine Levels, Chemical Studies and Bacterial Flora of Alternate Frozen/Thawed Market-Simulated Marine Fish Species, in Progress in Food Preservation (eds R. Bhat, A. Karim Alias and G. Paliyath), Wiley-Blackwell, Oxford, UK. doi: 10.1002/9781119962045.ch15

Editor Information

  1. 2

    Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, Penang, Malaysia

  2. 3

    Department of Plant Agriculture, University of Guelph, Guelph, Canada

Author Information

  1. Department of Wildlife and Fisheries, Management, University of Ibadan, Ibadan, Nigeria

Publication History

  1. Published Online: 16 JAN 2012
  2. Published Print: 10 FEB 2012

ISBN Information

Print ISBN: 9780470655856

Online ISBN: 9781119962045

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Keywords:

  • chemical studies;
  • contamination;
  • handling;
  • hypoxanthine;
  • marine fish species;
  • preservation;
  • shelf life;
  • spoilage bacteria

Summary

In this chapter the results obtained in one of our interesting studies on alternate frozen/ thawed market-simulated marine fish species is discussed. Hypoxanthine levels were standardized with chemical indices and bacterial flora/count of three marine fish species: Pseudotolithus senegalensis (croaker), Scomber japonicus (chub mackerel) and Sardinella eba (sardine). Fish were exposed to 12 h of thawing (weekly) to simulate market conditions before refreezing and analysis for a 12-week cold storage period at –4°C. Organoleptic assessment of the cooked fish was best for the fresh basal fish sample, while chemical studies and bacteria flora revealed that S. eba had the highest spoilage rate with 12 bacteria species isolated followed by Sc. japonicus with 10 bacteria species and P. senegalensis with seven bacterial species. A total viable count range of (1.60–5.58)x105 colony-forming units/g, trimethylamine of 24.1231.20 mg/100 g fish, peroxide value of 22.5029.40 mEq/kg fish, free fatty acid of 1.53–2.16% and hypoxanthine levels of 25.3233.84 mg/100 mg fish were recorded for P. senegalensis, which were much lower than in the other two species studied. Incidence of Lactococcus acidophilus was observed in all three fish species stored from week 0 (basal sample), possibly due to contamination during handling. The bacteria of highest prevalence in the study were Bacillus cereus, L. acidophilus and Pseudomonas aeruginosa.