The Wonder of Tomatoes – Who has got the blues?
By Hans Wieland
The Tomato Colour Spectrum – Taste the Rainbow!
If we accept that there are around 7500 varieties of tomatoes according to Wikipedia and that Gerhard Bohl, a German collector grows 3000 varieties, then the 60 plus varieties we trial at The Organic Centre this summer are actually ‘peanuts’, if you allow me that comparison. Nevertheless they are growing away, setting fruit and fighting aphids. Some have leaf curl, they are side-shooted and given Comfrey liquid and get encouraging words each morning from dedicated staff and students to prepare them for their big day when chefs Neven Maguire, Piero Melis and Brid Torrades will be tasting and testing and will answer the question: “Mirror, mirror on the wall, who is the sweetest of them all?”. Assisted by our former head gardener Klaus and myself and everyone at the centre, the task is to discover a variety that can beat the sweet cherry tomato Sungold on taste.
But back to basics first and the reality that growing tomatoes in Ireland has only really been made possible for the wider public with the arrival of polytunnels merely 30 years ago. So, in comparison to the growers in southern Mexico, who cultivated tomatoes 500BC or the farmers of the Lower Andes, who have grown them since 1500, or the people of Italy, where the tomato arrived in 1522, we are really “green behind our ears” when it comes to tomatoes.
Size is not all that matters, colour does too!
We can classify varieties of tomatoes according to size and shape from round to cherry, plum to beefsteak, but today we will focus on colour. Originally, tomatoes were yellow to orange, then were bred mainly for red, later for yellow again and now for blue. The difference in color is not just superficial. The carotene lycopene is responsible for the red and pink colour of our classic or standard tomato, with a balance of sweet and acidic flavours and two varieties that are tipped to be amongst the winners of our contest – Volkov and Sweet Aperitif.
Then there are the yellow tomatoes with a slightly different nutritional profile than that of red ones. They have lots of niacin and folate like red ones, but less vitamin C and less lycopene. Perhaps most importantly, they are lower in acid than red tomatoes. For people who love tomatoes, but suffer when they eat acidic foods, yellow tomatoes can be a good middle ground for salads, pizzas, sauces and any other dishes where tomatoes may appear. The lower acid level also allows some of the more naturally sweet flavor of the tomato to come through, which can be an advantage in some dishes. I am especially looking forward to tasting the Yellow Zebra.
So what’s with the blue tomatoes?
It’s just what ‘tomato-heads’ are talking about right now. Researchers at Oregon State University (OSU), using conventional breeding techniques, have crossed domestic tomatoes with wild varieties to produce blue tomatoes that have high levels of anthocyanin, a compound that also appears in blueberries and that produces the healthy pigments in red wine. Anthocyanin, not present in red tomatoes, possesses antioxidant properties to make it a healthier tomato.
Blue OSU is the variety we’re trying this year at The Organic Centre and the colour ranges from a purplish blue to a dark, almost black colour. However, anthocyanin is only produced in the fruit in areas that are exposed to sunlight. If the fruit is shaded by a leaf or stem, that part of the fruit will remain green. Some breeders say only intense sunlight will lead to the most beautiful purple colour and here lies the challenge for ours: Can our unique Irish summer live up to expectations?
Along with the blue tomatoes, we can’t forget the whites, like Snowball, the Green Zebra and Black Zebra, red Shady Lady and yellow Beauty Queen, orange Hillbilly and silvery Freckled Child! If you grow a variety of tomato that you like and that has a great taste, we’d love to hear from you.