A new study has shown that gentle streams of water carrying sound and microscopic air bubbles can clean bacteria from salad leaves more effectively than current washing methods used by suppliers and consumers. As well as reducing food poisoning, the findings could reduce food waste and have implications for the growing threat of anti-microbial resistance.
A diet containing uncooked salad, fruit and vegetables is key to reducing a range of conditions, including cardiovascular diseases, Type II diabetes and certain types of cancer.
However, salad and leafy green vegetables may be contaminated with harmful bacteria during growing, harvesting, preparation and retail leading to outbreaks of food poisoning which may be fatal in vulnerable groups.
Because there is no cooking process to reduce the microbial load in fresh salads, washing is vital by the supplier and the consumer.
Washing with soap, detergent bleach or other disinfectants is not recommended and the crevices in the leaf surface means washing with plain water may leave an infectious dose on the leaf. Even if chemicals are used, they may not penetrate the crevices.
In this new study, published in the journal Ultrasound in Medicine and Biology, scientists used acoustic water streams to clean spinach leaves directly sourced from the field crop, then compared the results with leaves rinsed in plain water at the same velocity.
FoodWorld 