No easy solutions for storing fresh fruit

The shelf life of fresh fruit and vegetables depends not only on the age of the product but also on storage conditions.

Broccoli has a shelf life of 20 days at 5 degrees. At 20 degrees the shelf life is a mere two days. Labelling with a use-by date is therefore no guarantee for fresh products. Crucial to shelf life is how the products are handled and stored during the supply chain from farm to fork.

Fresh fruit and vegetables include over 200 plant food products that vary in quality and shelf life. Some products must be stored at a low temperature while others are sensitive to chilling injury at low temperatures. It is therefore important that the products are stored at an optimum temperature throughout the supply chain.

Some products are harvested and transported before ripening after which they ripen, while other kinds of fruit and vegetables are ripe at harvest. Shelf life is therefore variable and cannot be solved solely by introducing obligatory use-by dates.

- It is difficult to set down rules for use-by dates that are valid for all fresh fruits and vegetables, says senior scientist Merete Edelenbos, Department of Food Science at the Faculty of Agricultural Sciences, Aarhus University.

- What is also special about these products is that, in contrast to other food products, they are live entities that respire even though they are detached from the mother plant. This means that the character and quality of the products change; they degenerate with age and lose their freshness in a gradual process after harvest, says Merete Edelenbos. Crucial to post-harvest quality is how the products are stored and for how long. In this regard temperature plays a major role.

Report on the way

Scientists at the Department of Food Science and Department of Horticulture are presently preparing a report for the Danish Veterinary and Food Administration regarding shelf life of fresh fruit and vegetables, including how age and storage conditions affect the quality of fresh fruit and vegetables after harvest. The report is expected to be published in the beginning of 2011.

- It is very important that consumers and the fruit and vegetable sector gain more knowledge of how to handle and store fresh fruit and vegetables and consumers need to know what to look for when judging product quality in the store, says Merete Edelenbos.

Innovation project with new solutions

It is often necessary to package fresh fruit and vegetables to ensure their quality and avoid damage. Scientists from the Department of Food Science are therefore collaborating with the Danish Technological Institute to find improved ways of packaging fresh fruit and vegetables.