Anyone who knows me will confirm, I have a notoriously sweet tooth, so it stands to reason that where potatoes are concerned, you’ll find me gravitating towards the orange and purple varieties over a humble spud every time.
But just because they’re sweet, doesn’t mean they’re bad for you, on the contrary. In my new book, How to Eat Better, I’ve taken a closer look at sweet potatoes – from the blueberry-hued, antioxidant-packed Stokes Purple to the orange supermarket staple Covington − in order to decode their health benefits and provide you with some simple kitchen science to maximise their nutrition.
Sweet potatoes contain twice the fibre and one and a half times the vitamin C of regular potatoes. What’s more, they’re an extremely rich source of antioxidant carotenes − just one small serving of sweet potato offers up all the vitamin A you need in a day and more (higher than any other root vegetable), plus significantly more potassium, calcium and vitamin K, all for roughly the same calories as a standard spud.
While a bright purple or orange sweet potato, wrapped in foil and baked slowly in the oven at around 160°C for 1-1 ½ hours, is about the easiest healthy lunch going, at times I like to push the boat out. Sweet potatoes are so high in key nutrients that they have been extensively tested at the Kennedy Space Center as part of the rations of NASA astronauts, according to a 1998 study. Reading reports on how they were turned into pancakes, waffles, pasta, doughnuts, pretzels and so much more, I thought ‘I could do that!’ and created sweet potato & pecan doughnuts.
Made up of about 70 per cent fruit, nuts and veg, this is my NASA-inspired doughnut recipe – if you’re a fan of carrot cake then you really should try these. Enjoy!
Olive oil, for greasing
120g wholemeal flour
1 tsp baking powder
1 tsp mixed spice
½ tsp salt
3 tbsp granulated stevia (baking blend) or soft brown sugar
1 tsp vanilla extract
1 small banana
350g cooked orange sweet potato
50g pecan nuts, chopped
Melted chocolate (dark or white)
Chopped dried fruit (I used goji berries and freeze-dried strawberries)
Chopped nuts (I used flaked almonds and desiccated coconut)
Preheat the oven to 180°C/Gas mark 4. Grease 9 sections of an 8.5cm doughnut tray lightly with a little oil.
Whisk the flour, baking powder, mixed spice, salt and stevia or sugar together in a large mixing bowl.
Blitz the vanilla extract, egg, banana and sweet potato together in a food processor until smooth, then fold into the flour mixture with the pecans.
Spoon the mixture into the prepared doughnut sections and bake for 30 minutes, or until risen and golden. Leave to cool.
Decorate the doughnuts with melted chocolate, dried fruit and chopped nuts.
Top tip: I added a couple of drops of natural pink food colouring to some white chocolate to give these doughnuts added prettiness, but plain dark or white chocolate work just as well.