Who doesn’t love strawberries? What the Dutch call ‘summer kings’ look enticing, have a delicious taste and contain lots of vitamin C. Scientists at Wageningen UR Greenhouse Horticulture in Bleiswijk think that they can make the taste even better, the levels of antioxidants even higher and, especially, more constant. The trick? Exposing strawberries in a greenhouse to LED lamps.
One of the greenhouses of the newly opened Innovation and Demo Centre (IDC) Flavour in Bleiswijk is awash with the fresh sweet smell of strawberries. Four varieties – Elsanta, Sonata, Darselect and Honeoye – are arranged in neat rows. The LED lights above them immediately catch the eye. Scientist Jan Janse explains why they are there: “Here we demonstrate to growers, suppliers and breeders the ways in which the fruit composition and flavour of strawberries can be influenced via exposure to LEDs.”
Different types of light
Janse and his colleagues are studying which lighting strategy produces the best results for which variety. For this purpose, the plants are illuminated in different ways. In some rows, the light primarily comes from the outside, and is merely supplemented with LEDs high above in the greenhouse. In other rows, there are also LEDs hanging thirty centimetres above the plants. And then there is also special intermediary lighting, which focuses on both the leaves and the fruit.
Testing strawberries for taste
Various measurements are carried out on the fruit immediately after harvest, Janse explains. “For example, we check internal quality, such as sugar content, acidity, juiciness, firmness and antioxidant content. But we also have the fruits tested for taste by a large panel of consumers and a panel of trained experts.”
LEDs in tomato cultivation
Strawberry growers are following these tests with great interest, Janse says. “They know that a quarter of the tomato crop is grown with intensive light exposure. That is also a domain in which much more is already known about the impact of this cultivation technique. For example, we know that exposure of fruit to LEDs can double the vitamin C content in the fruit.”
If the demo in Bleiswijk shows that strawberries can also benefit from intensive exposure to light, growers could switch to this method too. “Provided that the investment pays off, of course – because, while LED lights are energy-efficient, they are still relatively expensive to purchase.”
In the Innovation and Demo Centre Flavour, researchers, breeders and distributors work together to promote and improve the taste of fresh vegetables and fruit. IDC Flavour is one of the four IDCs operated by Wageningen UR Greenhouse Horticulture in Bleiswijk. It gives growers, suppliers, breeders and public authorities the chance to familiarise themselves with innovative new methods for improving the taste and content of healthy compounds in fruits and vegetables. In addition, the focus on taste at IDC Flavour makes it a platform for added value creation in the supply chain.
The high interest in the platform was apparent on Friday 9 May during the official opening of the seminar ‘Flavour as a carrier of health’ and on Saturday 10 May at the ‘Festival of Flavour’ for the general public. “We still don’t eat enough fruit and vegetables in the Netherlands,” Janse points out. “The Festival of Flavour lets us show everyone, young and old, that healthy can also be really tasty and fun. We have an optimistic message for consumers, allowing us to make our own contribution to promoting horticulture.”