When stored in a fridge, without any further treatment or packaging, table grapes have a shelf life of no more than ten days. After this the quality deteriorates so much, due to water loss and general decay, that the product becomes unsuitable for sale. With conventional packaging and treatment methods (Modified Atmosphere Packaging (MAP)) the shelf life of table grapes can be extended to about 30 days. The members of the ‘Fresh Table Grapes Chain’ were convinced that there was still a lot of room for improvement. They expected that they could further extend the shelf life of grapes by upgrading conventional plastic grape containers with a smart 3d-printed device integrated in the plastic film and an adjusted atmosphere.

The coordinator of the use case, Vincenzo Verrastro, explains: ‘’the idea for an improved packaging method was already there for quite a while. What we needed was better 3d-printing options and a live lab for testing our solution. A few years ago, the 3d-printing technology was finally well-developed enough for what we envisioned. Then, when IoF2020 came along, it provided us with the perfect live lab. This accelerated the development, and gave us options for testing our innovation in the field’’. Now, three years since the start of this development, the Blow® device is a fact.  

The Blow® device  is a small 3d-printed filter, integrated into the film of an otherwise regular plastic fruit container. During packaging, the atmosphere within the container gets modified (MAP), creating an atmosphere in which mostly inactive gasses like carbon dioxide are present and where oxygen levels are low. The Blow® device, a roughly 0,6mm thick disc with a diameter of under 20 mm, serves as a bidirectional selective valve. It regulates the oxygen and carbon dioxide levels within the packaging. As a result, the shelf life of fresh table grapes gets extended to as much as 60 days or even more. Even in substandard temperatures and other storage conditions the grapes stay fresh for a much long period of time than those preserved using conventional methods.

The Blow® device can be found in the bottom left of the plastic film of this grape container. These organic Scarlotta Seedless grapes are photographed 81 days after packaging. Thanks to a combination of the Blow® device and a modified atmosphere created with inactive gasses these grapes still show fairly little sign of deterioration.

The extended shelf life that the Blow® device offers is extra good news for organic table grape farmers. The leading method of table grape shelf life prolongation is the application of Sulphur dioxide, which serves as a fungicide. However, the application of Sulphur dioxide is restricted for certified organic products, and organic grape farmers have very few other options for preserving their products post-harvest. The Blow® device will make it possible to substantially extend the shelf life of organic Table Grapes.

Next to table grape producers other fruit and vegetable producers too will benefit from this new device. The Blow® technology can for example also be used to extend the shelf life of other high perishable fruit and vegetables, like strawberries, lettuce, mushrooms and cherries.

The technology has proven itself, and is ready to go commercial, but the scale still needs to be enlarged. At the present time, the Blow® device cannot yet be automatically integrated into the existing packaging. Instead, it has to be integrated into the film manually during the packaging production process. A special packaging machine, serving as a proof of concept, was used for the trials. However, the technology will have to be integrated into larger, more automated packaging machinery in order to make the packaging method financially viable. This makes the automation of Blow® integration in large-scale packaging processes the next big challenge for the research group.

Furthermore, the use case team is now shifting their focus towards late variety table grapes. These are grapes that are harvested in the second half of September and later. Vincenzo Verrastro explains: ”By applying the Blow® technology to late variety grapes we aim to extend the European fresh table grape season towards the Christmas season.”