Featured Foods: Sweet potatoes
By Leslie Beck, RD See Bio
Registered Dietitian Leslie Beck is the best-selling author of 12 books on nutrition and health, writes a weekly column in The Globe and Mail and is a regular contributor to CTV News. Based at the Medisys clinic in Toronto, Leslie offers one-on-one diet coaching, personalized meal plans and evidence-based recommendations on the use of nutritional supplements. www.lesliebeck.comHide
Low in calories and packed with disease-fighting antioxidants, sweet potatoes are an all-round healthy choice. Sweet potatoes outrank all other vegetables when it comes to beta-carotene, a powerful antioxidant. Studies suggest a diet rich in beta-carotene can help guard against certain cancers and heart disease.
While there’s no official recommendation for how much beta-carotene we need each day, most experts agree that 3 to 6 milligrams per day is sufficient to help lower the risk of chronic disease. A half-cup (125 ml) serving of cooked sweet potato has12 milligrams of beta-carotene! That’s twice the beta-carotene found in ½ cup of carrots.
Sweet potatoes are also an excellent source of vitamin C. A half-cup (125 ml) serving provides 21 milligrams of the nutrient, almost one-third of a day’s worth for women and one-quarter of a day’s worth for men. Sweet potatoes are also a good source of fibre, niacin and vitamin B6.
Sweet potatoes are often mistakenly called yams. In many cases, “yams” sold in grocery stores are really just sweet potatoes. Yams are actually the tuber of a tropical vine and can vary in colour from ivory to yellow to purple; they’re popular in Latin American and Caribbean cuisine.
Nutritionally speaking, sweet potatoes and yams vary considerably. Yams contain less than 1 percent of the beta-carotene found in sweet potatoes and less than half the vitamin C.
Nutrient information per ½ cup (125 ml) cooked sweet potatoes:
|Beta carotene||12 mg|
|Vitamin B6||0.3 mg|
|Vitamin C||21 mg|
Source: Canadian Nutrient File, 2007b
There are many varieties of sweet potatoes but the two that are most readily available in markets and stores are the moist orange-fleshed variety and the dry yellow-fleshed variety. The moist orange-fleshed variety is the most popular and is distinguishable by its vibrant orange colour, dark orange skin and sweet taste. The dry yellow-fleshed variety has light yellow skin and pale yellow flesh.
Choose fresh sweet potatoes that are small to medium in size and firm to the touch. Sweet potatoes should be heavy for their size. Avoid any that are cracked, bruised or have visible soft spots.
For optimal taste and texture, store sweet potatoes in a cool, dark and dry place, such as a cold cellar. Sweet potatoes maintain their freshness best when are stored between 12°C and 15°C. Sweet potatoes should not be kept it the refrigerator – the cold temperature can produce a hard core in the centre of the potatoes and cause an “off” taste.
Stored properly, sweet potatoes will keep for a month or longer. If kept at normal room temperature, sweet potatoes should be used within one week of purchase.
There are countless ways to prepare sweet potatoes – from baking to steaming to grilling. They can even be eaten raw!
Sweet potatoes have a very thin skin, which is edible when cooked. If you plan on eating the skin on cooked sweet potatoes, be sure to gently scrub the sweet potato under running water to remove any dirt or dust.
Fresh (raw): Wash and peel sweet potatoes. Cut the sweet potatoes into sticks. The North Carolina Sweet Potato Commission recommends putting the potatoes on ice water or in a plastic bag with several ice cubes for 10 minutes to help prevent the potatoes from discolouring. Raw sweet potato sticks are ideal for eating on their own or serving them with low fat dip or hummus.
Baking: Preheat oven to 400°F (200°C). Pierce the potatoes with a fork or small knife and place them on a lined baking sheet and bake for 30 to 60 minutes, depending on their size, until potatoes are tender. Alternatively, cut sweet potatoes into thin wedges, toss with olive oil and bake for 30 to 40 minutes, or until cooked through.
Grilling: Preheat grill over medium heat. Peel sweet potatoes if you prefer, and then cut sweet potatoes crosswise in ¼ to 1/3 inch thick slices. Lightly coat the sweet potatoes with oil and season as desired with sea salt, coarsely ground fresh pepper or dried herbs and spices. Place sweet potatoes on grill and cook until potatoes are tender, turning every 4 to 6 minutes.
Steaming: Chop sweet potatoes into 2-inch cubes. Bring 1 to 2 inches of water to a boil in a small saucepan. Place sweet potatoes in a steamer basket and place in the saucepan. Reduce heat to medium, cover and cook for 15 to 20 minutes, or until sweet potatoes are tender and soft. Remove potatoes from basket and serve on their own or make mashed sweet potatoes.
Thanks to their sweet taste and vibrant orange colour, sweet potatoes are pair well with many dishes both sweet and savoury. From sweet potato pie to sweet potato fries, this is one vegetable that has endless possibilities in the kitchen!
Healthy ways to enjoy
• Add mashed sweet potatoes to homemade muffins, quick breads and pancake batters for an infusion of beta-carotene.
• Add grated raw sweet potato to omelets and frittatas.
• Top a salad with grilled sweet potatoes instead of croutons.
• Enjoy a warm bowl of sweet potato soup. Click here for a recipe.
• Add grated raw sweet potato to coleslaw for a new take on an old favourite.
• Forget regular old mashed potatoes – serve mashed sweet potatoes instead! Season to taste with orange juice, maple syrup, cinnamon or sea salt. Click here for a recipe.
• Make homemade oven-baked sweet potato fries – they’re addictive and much healthier than deep-fried French fries. Click here for a recipe.
• Add sweet potatoes to a homemade curry with cauliflower and lentils.
• Finish your meal with a delicious slice of sweet potato pie – a great alternative to pumpkin pie.
• Cut raw, peeled sweet potatoes into thin sticks and serve alongside low-fat dip or hummus.
• Make sweet potato chips – a nutritious alternative to store-bought potato chips.
Did you know?
• Sweet potatoes are native to Central America.
• The main commercial producers of sweet potatoes include China, India, Indonesia and Japan.
• Sweet potatoes are part of the morning glory family.
Registered Dietitian Leslie Beck is the best-selling author of 12 books on nutrition and health, writes a weekly column in The Globe and Mail and is a regular contributor to CTV News. Based at the Medisys clinic in Toronto, Leslie offers one-on-one diet coaching, personalized meal plans and evidence-based recommendations on the use of nutritional supplements. www.lesliebeck.com