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Fresh if packaged correctly

Fresh fruit and vegetables have longer shelf-life if packaged correctly. This is the conclusion of a recently completed research project. The results, which can help prevent food wastage, were presented at a seminar in Odense.

[Translate to English:] Det er vigtigt, at frugt og grønt emballeres korrekt for at det kan holde sig frisk og indbydende. Foto: Janne Hansen

Soggy salad, slimy spinach and rotten radishes are some of the least pleasant food products to have in one's fridge. These fresh products go straight in the bin and thus contribute to Denmark's enormous food wastage: Danes throw away 3.1 billion kroner worth of fruit and vegetables every year.


There is hope to be had, though. A research project shows how fruit and vegetables can be  packaged so that the products  remain fresh for longer. The results from the project; ”Product-designed packaging of fresh fruit and vegetables” (www.friskpak.dk) were presented at the seminar ”Packaging of fruit and vegetables” on the 8th of January 2013 in Odense. The seminar gave an overview of the possibilities and challenges of packaging fresh fruit and vegetables either as fresh or fresh-cut produce. There was in particular a focus on practical tools to be used in the industry.


The optimal packaging

A focus area in the project has been to investigate the packaging of fresh fruit and vegetables in order to obtain optimal packaging solutions.


- If you want to find the optimal solution, you have to have knowledge about the respiration of the fresh product and the physical properties of the packaging material, explains associate professor Merete Edelenbos from Aarhus University. She has been looking into these factors in a series of experiments with product-designed packaging of fresh fruit and vegetables. She and the partner, Danish Technological Institute, have also tested the quality of packaged fresh produce in the retail. While 20 per cent of the fresh produce was seen to ferment in the past, no fermentation is seen today. With fresh-cut produce the same positive picture was seen. In the past, 44 per cent of the products fermented before the “best before date”, while it is down to 20 per cent today.

- When fresh produce ferments, the products are usually packaged in materials with  too low an oxygen transmission rate. Fruit and vegetables respire, or breathe, so if the gas exchange rates of the packaging are too low compared to the needs of the product, the oxygen levels may drop below 2 kPa and the risk of losing quality increases dramatically, explains Merete Edelenbos. The products simply emit gasses which will make them smell wrong and badly. Not exactly something that makes you want to eat packaged fresh produce.

Respiration and temperature
To find the optimal packaging solution, you have to know the respiration rate of the product and the storage temperature. The higher the storage temperature, the more oxygen is consumed. It is therefore mandatory that fresh produce is stored at the stated temperature throughout the distribution chain, when using product-designed packaging.

- It is important that the product is stored at the stated temperature after packaging. Even a short break in the cooling chain will result in  too high an oxygen consumption rate and  too low an oxygen level inside the packages. If the required knowledge on fresh produce packaging is not available and producers and retailers do not cooperate about keeping the cold chain, product-designed packaging can be very risky. That is what we call “pack and pray”, says Merete Edelenbos.

The project is supported by funds from the Danish Agency for Science, Technology and Innovation and is a collaborative effort between the Danish Technological Institute (which is leading the project), Aarhus University, HortiAdvice Scandinavia, Scanstore Packaging, NNZ Denmark, PBI Dansensor, Multivac, Linde/AGA, COOP, Axel Månsson, Yding Grønt, Tange Frilandsgartneri, Slice Fruit, Gl. Estrup, Aarstiderne, Ørskov Frugt, CFS, Videometer, Svanholm, Peter Skov Johansen, Lykkegården, Danish Fruit growers, Gartneriet Torup and Ventegodtgård.

Read more about Friskpak here.

Further Information: Associate professor Merete Edelenbos, Department of Food Science, email: merete.edelenbos@agrsci.dk, telephone: +45 8715 8334, mobile: +45 2945 0133