2007/719 Protecting the safety and quality of Australian oysters with integrated predictive tools

By Mark Tamplin

Molluscan shellfish are high-valued seafood products that require careful supply chain management to guarantee both product safety and quality. Together, storage time and temperature exert the greatest influence on microbial food safety and must be controlled during production, processing, transport and storage. The microbiological safety status of oysters is initially controlled by testing, monitoring and classifying shellfish-growing waters as safe for harvest.

Vibrio parahaemolyticus is a natural bacterial species found in seawater. Occasionally, pathogenic V. parahaemolyticus strains can cause mild to severe diarrhoea when oysters are eaten raw. Temperature is a key factor for controlling V. parahaemolyticus growth in oysters. However, there is little information about how fast V. parahaemolyticus grows in Australian oyster species (Pacific and Sydney Rock Oysters) at different storage temperatures.

Development of a predictive model for V. parahaemolyticus growth in oysters can improve management practices if implemented to control temperature during post-harvest processing, storage and transport. Such interventions could decrease the number of oysters in the marketplace that exceed recommended maximum limits and also decrease cases of Vibrio infection. This can be achieved, in part, by producing a tool (Oyster Refrigeration Index) that allows companies to monitor conditions of the cold chain and thus the safety and quality of a highly-valued seafood product. The likely impact will include: 1) improved product safety, 2) an optimised cold chain, 3) higher product quality, 4) greater access to export markets and 5) a more cooperative regulatory environment. The objective of this project was to produce a validated and robust V. parahaemolyticus model approved by Australian and international regulatory bodies to manage the live oyster cold chain, control the risk of Vibrio parahaemolyticus disease and provide greater access to national and international markets.

To access the oyster refrigeration index click here: http://www.explorerisk.com/FSVibrio/Default.aspx