How bubbles create cleaner fruit and vegetables
The technology was first studied as a means of reducing the amount of water used in cleaning through the addition of air. Adding tiny bubbles also causes a natural scrubbing action as they move around. However at the workshop Dean will stress the bubbles’ ability to reduce the volume of microbes found on fresh produce, potentially reducing the use of chemical disinfectants.
Horticultural growers make concerted efforts to ensure their produce is free of contaminants which could damage human health. This often involves using disinfectants called biocides to kill off microorganisms in irrigation and produce wash waters and to disinfect equipment and surfaces. Biocides kill bacteria such as E. coli 0517 before produce is sold, however chlorine-based biocides can lead to chemical compounds known as chlorate or perchlorate being left on produce.
Dean says: “Bubble technology has been used in Japan for a number of years and is just beginning to catch on here. Washing surfaces or produce using water with fine bubbles destroys 90% more microorganisms than using water alone. Creating bubbles in water can also disinfect the water itself as the agitation produces free radicals which act as cleaners. The technology has also been seen to improve plant growth and this is thought to be due to increasing the oxygen and nitrogen content of the water.”
As well as being effective, the fine bubble technology is also relatively cheap. Growers can purchase specially designed nozzles and combine them with existing kit to aerate their water supply.
Grace Choto, AHDB Research and Knowledge Exchange Manager, says: “Many growers who are keen to ensure their produce is free of potentially harmful microbes use biocides for disinfection purposes, however these are coming under scrutiny from the European Commission. There is now a need to ensure that primary production practices do not leave much chlorate or perchlorate residue on fresh produce. Maximum residue levels for chlorate were proposed by the Commission in November 2015, these are available on the AHDB Horticulture website.
“The ‘Keep it Clean’ Microbials workshops around the UK will provide growers with novel methods and guidelines to help ensure that produce is free from microbial contaminants.”
The events will be held at 5 locations around the UK, including Fife (15th or 16th Feb), Bolton (21st Feb), Claverdon (1st March), Maidstone (7th March) and Taunton (21st March). Growers interested in attending an event should visit horticulture.ahdb.org.uk/events