This week's national recall from supermarkets of a selection of pre-packed lettuce grown in Victoria is a timely reminder to all home gardeners to make sure they thoroughly wash their home-grown produce.
The Victorian Department of Health and Human Services is investigating the cause of the Salmonella contamination, including whether the contamination came from soil or irrigation water.
Tasmanian Institute of Agriculture Associate Professor of Microbiology John Bowman says Salmonella contamination in food is usually linked to contact with animal faeces and is a risk that home gardeners also need to be aware of.
"Birds are known carriers of Salmonella, so it is possible for wildlife that enter the garden or uncomposted animal manures used as fertilisers to contaminate fresh fruit and vegetable produce," he said.
"It is important that home gardeners are aware of this and make sure they avoid using fresh animal manure on their vegetable gardens.
"You must make sure that all composts, including animal manure from poultry, cows, horses and sheep, are thoroughly composted to kill pathogens such as Salmonella and E. coli.
"The heat and other stresses from the composting process lowers the risk of pathogen contamination dramatically by 100,000 fold or more, but the composting must be done correctly to ensure pathogens are killed.
"Composting takes time and requires active management. You need the right mix of materials, moisture and regular turning to ensure all of the compost is repeatedly exposed to temperatures of 70-75 degrees Celsius to kill pathogens."
Associate Professor Bowman recommends washing all home-grown produce thoroughly and taking extra care with produce that is eaten raw and grows close to the ground such as lettuce and strawberries that could be easily contaminated by soil.
"You should always wash your home-grown lettuce thoroughly by separating the leaves and submerging them in a clean sink full of fresh water," he said.
"Give them a good swirl in the water to help to dislodge as much soil and bacteria as possible and then remove as much of the water as possible by spinning the leaves in a lettuce spinner."
A key priority outcome of TIA is to strengthen Tasmania's and Australia's reputation for safe, high-quality products and processes through research on food and supply chain safety and quality through modelling of microbial hazards, predictive tools, scenarios and foresighting.
TIA is a joint venture of the University of Tasmania and Tasmanian Government.
Published on: 05 Feb 2016 2:34pm