Why Oranges Are Good for You

Make the most of citrus season and grab unwaxed organic varieties for flavour and nutrition
The zesty, citrus whiff of oranges freshens up the January kitchen, drawing a line under heavy celebratory food, and lighting up the virtuous, but enticing path to a lighter, healthier diet. With the European citrus season in full swing, the art is choosing fruits that haven't been chemically waxed in preparation for storage and so retain some of their just-picked freshness.Avoid the hard, immature fruits that are inflicted on the UK market, and home in on those that are softer, with matt, untreated, fungicide-free skins. Sicilian blood oranges (moro, tarocco), with their sumptuous purple juice, are the cream of the crop, and in my experience, rarely waxed with pesticides, because they are generally sold out within a couple of months. But any organic oranges will also have a soft skin and, with a bit of luck, some of that tree-ripe fragrance.Why are oranges good for me?They contain prodigious amounts of vitamin C, which protects the immune system and disarms free radicals that cause cell damage. Their abundant folate reduces levels of homocysteine, the cardiovascular risk factor, which can build up in our blood, while their store of potassium helps lower blood pressure. It's best to eat them whole: the papery pith contains valuable plant compounds (hesperidin, naringenin, limonene) that add to their antioxidant properties, along with soluble fibre, which slows down the absorption of fruit sugar in the bloodstream.Where to buy and what to payOranges cost as little as 20p a piece, but for softer, tree-ripe fruits that peel easily and are a treat to eat, you'll need to pay 50-65p. If you get through a lot, a whole box from a greengrocer will work out significantly cheaper.Joanna Blythman is the author of What To Eat (Fourth Estate, £9.99). To order a copy for £7.99 with free UK p&p, go to theguardian.com/bookshop

Roast fennel and radicchio with orange and anchovy dressing

A fragrant, fulsome midwinter supper.Serves 4
4 oranges, 3 segmented with juice reserved, 1 zested and juiced
100ml olive oil, plus 2 tbsp for roasting
8 tinned anchovy fillets plus 1 tbsp of oil
2 garlic cloves, crushed
1 tsp fennel seeds, toasted and ground
½ tbsp sherry vinegar
2 heads of fennel, trimmed, cored and cut into quarters lengthways
2 heads of radicchio, cut in half lengthways, cores removed and each half cut into sixths
480g orecchiette pasta
A small bunch of chives, chopped
40g parmesan, grated1 Put a large pan of salted water on to boil. Preheat the oven to 190C/375F/gas mark 5 with a roasting tray inside.2 Blanch the fennel for a couple of minutes. Add the oil to the preheated tray and return to the oven. Drain the fennel, and leave the water on the hob.3 Put the fennel and radicchio on the roasting tray, mix well and season. Roast for 15-20 minutes, until the vegetables are golden.4 Meanwhile, make the sauce. Put the garlic, fennel seeds, orange zest, sherry vinegar and anchovies in a food processor and whizz to a smooth paste. Slowly add the oil while the motor is running to get an emulsion. Once you have a nice smooth sauce, slowly add the orange juice and season to taste.5 Cook the orecchiette to the packet instructions, drain and return to the pan. Add the fennel, radicchio, orange segments and the dressing. Toss everything together, add the chives, mix well and serve. Pass the parmesan around separately.Rosie Sykes is head chef of Fitzbillies (fitzbillies.com) and co-author of The Kitchen Revolution (Ebury Press, £25). To order a copy for £19.99 with free UK p&p, go to theguardian.com/bookshopPhoto: Oranges contain large amounts of vitamin C, which is good for your immune system. Photography: Riou/Getty Images