The Fresh Prepared Salads Producer Group, which represents the main suppliers of washed and ready to eat salads to UK supermarkets have issued a defence of the use of modified atmosphere packaging and chlorine.
One of the criticisms levelled at the product is that the use of modified atmosphere packaging destroys the nutritional value of the salad and misleads the consumer into believing that the salad is fresher than it really is. This is simply not the case, the group said.
Leaf continues to respire after it has been harvested – and, as a result of this natural and inevitable process, it starts to deteriorate. This deterioration affects both nutritional and visual quality. Careful handling and packaging will slow this deterioration and optimise quality and freshness.
Occasionally, MAP is used to slow respiration and, therefore, optimise quality during the product’s life. This technique is used for approximately 20% of salad packs – only certain leaves show a strong response to modified atmosphere. The MAP process involves modifying the balance of the natural gases found in air – most often just reducing the level of oxygen in order to slow down respiration. This is a perfectly safe process.
Italian research published last year resulted in news stories about the loss of nutrient levels in salads, claiming that this was due to the MAP process. However, the study compared four-day-old salad packs with freshly picked whole head lettuce. Not surprisingly the fresher lettuce was shown to contain more vitamins. The nutritional decline had nothing to do with modified atmosphere ….as we all know, the fresher the food the higher the vitamin content.
By far the most important techniques for maintaining product freshness are careful handling, prompt preparation and refrigeration. Consequently, the manufacturers of prepared salads and their supermarket customers operate very efficient supply chains.
By volume, over 99% of salads used for pre-packed salads are sourced from the UK and continental Europe. The two main, growing regions are the UK in the summer and Spain during the winter. Salads grown in the UK are harvested, packed and on the supermarket shelf within 24 to 72 hours. If they come from Europe, it can take between 3 to 7 days. Whether from the UK or Spain, the salads are prepared and dispatched as quickly as possible once they arrive at the producers’ premises. It is in the industry’s interest to use local crops in order to have fresher products and most packing factories are situated near to key growing areas.
Work carried out earlier this year confirms that there is significant nutritional value in salads whether these have been pre-prepared or not. Moreover, it shows that the variety of highly nutritious leaves available in mixed salad packs can make a substantial contribution to recommended daily intakes.
Another area of concern has been the use of ‘chlorine’ in the wash process associated with prepared salads. Because the leaf used in prepared salads is grown naturally in fields, it is essential that it is washed before packing. Prepared salad leaves are washed thoroughly in water to ensure that they are safe to eat. This water is treated, in most cases, with chlorine to ensure that it remains clean and effective.
The process of chlorination is well established and safe. It is used for many applications including the supply of drinking water. However, concerns have been raised about the technique because of the possible formation of chlorination by-products that may be linked to ill health. Because of the concerns raised, the manufacturers of prepared salads have recently carried out a programme of testing to identify which (if any) by-products are present and to re-confirm that their products are safe.
In order to do this, the industry has taken independent advice from an expert closely involved in setting WHO guidelines for water quality and well placed to interpret the effect of the prepared salad process.
In tests, a range of prepared salads was checked for a number of possible chlorination by-products. In the vast majority of cases, no compounds were detected. Where levels were detected, they could only be measured in ‘parts per billion’. These tiny levels pose absolutely no threat to health and are substantially below WHO health guideline levels. The outcome of these tests clearly demonstrates that there is no cause for concern.
As an industry, we are continually looking at ways of improving the quality of our products for the consumer and invest heavily in research to this end.
Prepared salads remain an excellent way to help people achieve their consumption of 5 portions of fruit and vegetables per day.