2008/737 An investigation of the microbiology and biochemical properties leading to extended shelf-life in Goldband Snapper

By Rachel Tonkin


Goldband Snapper (Pristipomoides multidens) is a commercially popular fish in Australia due to its year round availability, and it has an unusually long shelf life compared to many other fish species. Previous studies have indicated that the microflora present on the fish skin influences shelf life, however, no extensive studies have been performed. A comprehensive investigation into the shelf life of Goldband Snapper was undertaken in this study using microbiological, biochemical, sensory and physical analyses.

Biochemical and sensory analyses demonstrated a difference existed between the spoilage of Goldband and Saddletail Snapper, however, they did not explain why Goldband Snapper had a longer shelf life. Results from the microbiological analyses demonstrated that the microflora present on Goldband Snapper had an impact on its shelf life. The increased levels of Pseudomonas species at the beginning of storage appeared to limit the number of Shewanella species resulting in an extended shelf life. Investigation into the microflora of other tropical species to confirm these results needs to be undertaken. Testing for genetic differences between each of the Pseudomonas species should be also carried out and the spoilage potential needs to be quantified for each of the species isolated. The knowledge obtained from this project will contribute to a wider understanding of fish spoilage and allow treatments and other preventative measures to be developed to increase shelf life across a range of fish species caught in Australia.