Report on food handling practices and microbiological quality of sushi in Australia, July 2008. 26pp, pdf KB
Background
A national coordinated survey from June 2006 to June 2007 determined the food handling practices and microbiological quality of retail sushi products.
Sushi is normally regarded as a potentially hazardous food yet is often displayed and sold out of temperature control.
Samples in the survey were tested for:
- chemical aspects - pH & water activity - of acidified rice
- microbiological quality indicators and pathogens present in sushi
- histamine levels in raw seafood
89 outlets displaying sushi in enclosed cabinets or moving conveyor belts were randomly included, located in ACT, NSW, NT and SA.
Winter and summer samples were identified and compared.
The survey also included a questionnaire on how:
- rice was acidified and stored, and
- sushi was prepared and displayed.
The survey was conducted under the Coordinated Survey Plan of the Food Regulation Standing Committee's (FRSC's) Implementation Sub-Committee (ISC). NSW Food Authority was the lead agency for the survey.
Results
Microbiology
Generally very good with acceptable results for:
- 98.6% of sushi rice samples , and
- 94.6% of sushi samples.
Sushi
6 samples were categorised as potentially hazardous due to elevated levels of Bacillus cereus.
Sushi samples had significantly higher levels of faecal coliforms and E. coli in the summer months.
Histamine
All samples of raw seafood were found to be within the Food Standards Code limit for histamine levels.
Full report
For all unacceptable results, follow-up action was undertaken commensurate with the level of risk posed.
Safety control measures for sushi rice are discussed and references are included in the report.
Report contents (26 pages)
Executive summary
1. Introduction
2. Survey Objective
3. ISC Coordinated Food Survey
4. Food handling questionnaire
5. Sample collection
6. Method of analysis
Assessing microbiological quality of sushi
7. Results
- Survey responses
- Acidification and storage of sushi rice
- Preparation and display of sushi
- Microbiological and chemical results
- Acidified sushi rice
- Sushi - winter samples
- Sushi - summer samples
- Combined results
- Histamine testing
8. Discussion
- Control measures for sushi rice
- Preparation and display of sushi
- Microbiological quality of sushi
- Faecal coliforms and E. coli
- Bacillus cereus
- Coagulase positive staphylococci (S. aureus)
- Salmonella
- Listeria monocytogenes
- Vibrio parahaemolyticus
- Histamine
9. Follow up action
10. Conclusion
11. References
12. Attachments
- Food Handling questionnaire for sushi businesses
- Summary of questionnaire responses