Robin Gledhill, of Green Island, asks :-

A chef told me polypropylene chopping boards are less hygienic than wooden boards. Is this so?

Phil Bremer, a food-science microbiologist at Otago University, responded.

Despite this question generating a lot of interest over the last few years it has received relatively little scientific investigation and the experiments to date have provided conflicting and relatively inconclusive results.

While some studies have shown that wood chopping boards can reduce bacterial numbers, these studies have been relatively simplistic in that they added pure cultures of bacteria in solution to the boards. More realistic studies using bacteria associated with food debris have shown that there is little difference in the survival of bacteria on wood or non-porous chopping boards made of plastic or glass. Further, only some types of wood seem to have antibacterial activity. In general, regulatory agencies recommend the use of plastic chopping boards as they have been shown to be easier to clean and dry and they are generally more robust.

The key to enhancing food safety is not so much the material the chopping board is made out of, but how it is used, maintained and cleaned. All cutting boards should be cleaned after each use using hot soapy water and a brush, followed by rinsing and drying. Acrylic, plastic, glass, and solid wood boards can be washed in an automatic dishwasher.

Cutting boards can be sanitised with a diluted chlorine bleach or vinegar solution consisting of one teaspoon of liquid chlorine bleach in one litre of water or a one to five dilution of vinegar. Flood the surface with a sanitizing solution and allow it to stand for several minutes, then rinse and dry. Excessively scarred (cut) cutting boards should be discarded, as they are very difficult to clean.

The most important way to enhance food safety is to avoid cross contamination. Use a separate cutting board for raw foods that require cooking, such as meat, poultry, or fish, and foods which are ready-to-eat such as salads, vegetables or breads.