Coloured vegetables rediscovered

by gabeatkinson / 06 December, 2012
Colourful vegetables are not new, they’re just old varieties rediscovered.
Cape broccoli, also known as purple cauliflower. Photo/Thinkstock

Question:


Do the new ranges of coloured vegetables, such as purple and orange cauliflowers and black carrots, have the added nutritional value of the other coloured vegetables we now understand to be good for us? Are they the result of genetic modification? And can you suggest a recipe, other than a stir-fry, for rainbow chard stems?

Answer:


A few decades ago, I begged my mum to buy me fluorescent pink socks. When combined with my dangly fluorescent earrings, the outfit screamed 1980s. But walk through any shopping mall today and you’ll find another generation donning neon-coloured summer clothes. And let’s not forget this year’s Olympic athletes sprinting across our TV screens in fluoro yellow running shoes.

Clothes aren’t the only cyclical fashion in our lives. The highly coloured cauliflowers and carrots appearing in shops typically aren’t new varieties, but rather they’re old ones rediscovered. These plant lines have simply been ignored until recently, often because of a lack of good agronomic characteristics, such as high yield and tolerance to plant diseases, according to Plant & Food Research, a Government-owned Crown Research Institute (CRI).

Indeed, some highly pigmented lines were actively selected against by growers during the development of crops, explains Plant & Food Research. Some lines were avoided because of poor post-harvest performance or taste disadvantages. Purple carrots, for example, typically aren’t as sweet as orange varieties. In other cases, the pigmentation was a convenient marker for plant breeders to use, as the “red gene” was found on the chromosome next to genes associated with poor agronomic characteristics. So plants bred with reduced pigmentation were less likely to have these indirectly associated problems.

Growing awareness of the potential health benefits of plant pigments, however, has led to breeder focus on colour as a major breeding trait to be combined with good agronomic performance, says Plant & Food Research, which is involved in the development of highly pigmented fruit and vegetable varieties through conventional breeding techniques. Scientists are breeding anthocyanin-rich potatoes and sweet potatoes, and working to identify the genes that control colour in onions.

“Plant & Food Research is interested in how these coloured compounds affect human health, then using this information to breed new varieties of vegetables and fruits with optimised concentrations of those with beneficial effects. We’re also looking at making sure people eat the right combinations of these nutrients for maximum benefit.”

The new “vitalvegetables” product range, developed by the CRI and the Australian Department of Primary Industries, offers packaged vegetable combinations with fast-acting and long-lasting nutrients at a guaranteed level in each serving. The vitalvegetables “immunity medley”, for example, contains purple-pigmented cauliflower florets, “Booster” broccoli, baby carrots and white cauliflower. This assortment is regularly tested to ensure each 100g serving provides 25% of the suggested daily antioxidant intake.

Still, there’s no one-size-fits-all answer on the nutritional benefits of pigmented produce, as it depends on the particular vegetable. For example, adding purple pigments to brassicas such as cauliflowers is likely to increase their overall health properties, but it’s less straightforward with carrots. Whereas purple carrots contain more anthocyanin pigments, which probably have health benefits, they also have fewer orange carotenoid pigments, which are definitely beneficial for health. Little is known about the health benefits of betalains, the group of pigments that provide the colouring in swiss chard and silverbeet.

In the end, beautifully coloured vegetables make an inspiring, healthy addition to a meal, and unlike with having fluorescent socks, almost every one will benefit from having more in their life.

RAINBOW CHARD INSPIRATION FROM LAURAINE JACOBS



  • Gently sauté chopped stalks and leaves of rainbow chard in olive oil.

  • Spread the mixture over frozen puff pastry or a few sheets of filo pastry.

  • Top with nuts, chopped herbs and grated parmesan, then bake in the oven at a high temperature for 10 to 15 minutes or until the pastry is crisp.


Email: nutrition@listener.co.nz
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