CFS announces risk assessment study results on microbiological quality of salads

The Centre for Food Safety (CFS) of the Food and Environmental Hygiene Department announced today (October 13) the results of a recently completed risk assessment study on the microbiological quality of salads. The study results showed that the vast majority of salad samples did not have food safety concern and the hygienic quality was generally satisfactory. Nevertheless, as microbiological contamination of ready-to-eat and raw fresh produce and their products was found possible, the CFS reminded the public not to ignore the potential risks involved.

A spokesman for the CFS said, "Salads are a mixture of raw vegetables which are popular among consumers in Hong Kong. In view of recent overseas studies and reports indicating the health risk of salads arising from contamination with pathogens, the CFS has conducted this risk assessment study to have a better understanding of the latest situation on the microbiological quality of salads composed primarily of raw vegetables available for sale in Hong Kong. Samples taken involved ready-to-eat and raw hydroponic and aquaponic salad vegetables.

"In this study, from September 2016 to February 2017, the CFS collected a total of 101 salad samples from the local market, including eight hydroponic and four aquaponic salad vegetable samples, for testing of specific food-borne pathogens (i.e. Escherichia coli (E. coli) O157, Salmonella spp, and Listeria monocytogenes) and testing for a hygienic indicator (i.e. E. coli)."

Results showed that except for one salad sample which was found to contain Listeria monocytogenes at a level of 2 400 colony-forming units per gram (cfu/g) announced earlier, exceeding the standard of the Microbiological Guidelines for Food which states that no more than 100cfu/g of the pathogen should be detected, the remaining 100 samples reached the satisfactory level of pathogens tested. Regarding the hygiene indicator (i.e. E. coli count), none of the samples taken were found to be unsatisfactory according to the Guidelines.

The spokesman said that for the salad sample detected with excessive Listeria monocytogenes, the contamination might have been caused by the use of contaminated raw materials, inadequate temperature control or post-processing contamination.

The spokesman said that though the study results showed that the microbiological quality of the salad samples in general was satisfactory, members of the public (particularly susceptible groups) should not ignore the potential risks associated with possible microbiological contamination of ready-to-eat and raw fresh produce and their products.

Susceptible groups (including pregnant women, children, the elderly and people with low immunity) are advised not to eat pre-prepared or prepackaged salads. They are advised to prepare their own salads, put freshly made salads in the refrigerator immediately and consume them as soon as possible.

"Moreover, wash hands with clean running water and soap thoroughly before handling salads and ready-to-eat raw salad vegetables; avoid cross-contamination when handling vegetables that will be eaten raw (e.g. use one cutting board for ready-to-eat food and a separate one for raw non-ready-to-eat food); and handle products in accordance with manufacturers' instructions," he said.

The spokesman also appealed to the trade to follow Good Manufacturing Practice to help control associated microbial hazards, and provide clear specific directions on product storage and use-by dates or other shelf-life indicators. They should also specify the need to keep washed ready-to-eat prepackaged fresh leafy vegetables refrigerated until use and provide other guidance on how to safely handle fresh-cut, pre-cut or ready-to-eat leafy vegetables. Food handlers should maintain good personal hygiene and observe good hygienic practices when handling food.

The study is available on the CFS' website at www.cfs.gov.hk.

Ends/Friday, October 13, 2017