- Processing Food -

Controlled atmosphere (CA) storage and ripening, and waxing

This is a procedure for storing fruits and vegetables, particularly apples, under an atmosphere that differs from air. Its aim is to increase the storage life of the foods. The most important dietary component of apples is dietary fibre, which is unlikely to be changed appreciably during CA storage. Significant nutritional changes in other fruits and vegetables would not be expected. For the uniform ripening of some fruits, most notably tomatoes and bananas, brief storage under a 'ripening gas' can be used. This can initiate ripening or speed up the process. Fruit produced for market in this way is unlikely to be significantly different in nutrient composition compared with fruit that has matured normally, although it may taste differently. Without CA storage many seasonal fruits would not be available throughout the year.

Many fruits and vegetables have a natural coating of wax, which is removed when these foods are cleaned before appearing on the supermarket shelf. To make them shiny and attractive and promote their sale, some fruits and vegetables are artificially waxed. The waxes are dispersed in water and coated over the food to provide a thin film of wax, which gives a glossy appearance. Apples coated this way are likely to sell more readily. In addition to this cosmetic effect, the wax coating for a short time slows the loss of moisture, which causes weight loss and wilting. The nutritional advantage of waxing, if any, would be expected to be only very small. At present there is no reason to believe that the use of waxes approved for this purpose is hazardous to health.