All produce, whether from the garden or commercially grown, carry microorganisms from the environment. Safety is assured by applying Good Agricultural Practice (GAP) from the seed onward, Good Hygienic Practice (GHP) from harvest and handling and Good Manufacturing Practice (GMP) during preparation. Washing is essential to remove the soil and debris before consumption.
Consequently, leafy salads sold as washed and ready to eat are thoroughly washed in water. The water is often chlorinated or treated with fruit acids to ensure that the leaves are as clean as possible and fit for immediate consumption without further washing.
Environmentally Acceptable Washing Methods
There is a constant development programme throughout the salad industry to find new efficient, cost effective, and environmentally acceptable washing approaches ranging from spring water washing through to the use of fruit acid based biocides and chlorine derivatives.
All washing approaches that are in commercial use have been assessed and validated as fit for purpose. However, minimising the opportunity for contamination in the field through the application of HACCP systems is key to assuring the microbiological quality of salad produce.
Careful use of Chlorine
When chlorine is used, levels are carefully monitored and kept to a level that is sufficient to keep the washwater microbiologically clean and prevent re-soiling. Levels used in the UK compare favourably with those in other countries where this technique is used. Levels of residual chlorine on the final product are negligible and the wash water is treated to remove any residual chlorine prior to discharge, as required by the Environment Agency.
Chlorinated water is currently the most efficient and cost effective way to keep the wash water clean. Other methods of sanitisation are being considered by the industry. However trials carried out by CFA member companies have not yet found any performance advantage over current systems. The industry continues to investigate alternatives.