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The effect of an antibacterial washing-up liquid in reducing dishwater aerobic plate counts
1Department of Food Hygiene, Campden and Chorleywood Food Research Association, Chipping Campden, Gloucestershire, UK. j.holah@campden.co.uk
Aims:
To assess any significant differences in the aerobic plate count (APC) of catering dishwaters following the use of a traditional, nonantibacterial or an antibacterial washing-up liquid.
Methods And Results:
A dishwashing trial was undertaken within a commercial restaurant of 6 weeks duration (3 weeks with each washing-up liquid in a randomized, weekly pattern). Five replicate samples were taken from the dishwater at the end of the washing-up operation, on three separate occasions each day corresponding to mid-morning, lunchtime and mid-afternoon meal preparations.
Conclusions:
The antibacterial product was shown to significantly reduce the APC by an average log10 reduction of 1.81 CFU ml(-1) (98.5%) as compared with the traditional product. APC were lower for each of the three weekly time periods for the antibacterial product. Continued use of the antibacterial product did not decrease the APC of the dishwater, though with the traditional product, dishwater counts increased throughout the trial week.
Significance And Impact Of The Study:
Antibacterial washing-up liquids, with proven activity in controlling levels of microorganisms in dishwaters, could play a significant role in reducing the risk of cross-contamination between washed articles during washing-up operations.
Insights
Antibacterial dish soap significantly reduced aerobic plate count (APC) in restaurant dishwater by 98.5% compared to traditional soap. This suggests antibacterial detergents can improve hygiene in commercial kitchens.
Area of Science:
- Microbiology
- Food Safety
- Public Health
Background:
- Maintaining hygienic conditions in commercial kitchens is crucial for preventing foodborne illnesses.
- Dishwater microbial load can be a source of cross-contamination.
- Traditional washing-up liquids may not adequately control bacterial growth.
Purpose of the Study:
- To compare the efficacy of antibacterial versus traditional washing-up liquids in reducing microbial counts in catering dishwater.
- To assess the impact of prolonged use on bacterial levels.
Main Methods:
- A 6-week randomized controlled trial was conducted in a commercial restaurant.
- Aerobic plate counts (APC) were measured from dishwater samples taken on three occasions daily.
- Both antibacterial and traditional non-antibacterial washing-up liquids were used for 3-week periods.
Main Results:
- The antibacterial washing-up liquid achieved a significant average log10 reduction of 1.81 CFU ml(-1) (98.5%) in APC compared to the traditional product.
- Lower APC were consistently observed with the antibacterial product across all sampling periods.
- While the antibacterial product maintained low counts, the traditional product showed increasing counts throughout the week.
Conclusions:
- Antibacterial washing-up liquids are effective in controlling microbial populations in catering dishwater.
- These products can significantly reduce the risk of cross-contamination during dishwashing operations.
- Their use represents a valuable tool for enhancing food safety in commercial settings.
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