Nutrition Notes
Often overlooked, summer’s sweet corn, which has an impressive nutrition profile.
One cup of corn delivers 143 calories, 5 g of protein and 31 g of carbohydrate. One large ear of corn (8 to 9 inches long) yields about one cup of corn kernels.
Sweet corn has a low glycemic index value, meaning its carbohydrates don’t spike blood sugar or insulin levels.
Corn is also a decent source of fibre, providing 3.5 g per one cup. Research has found that the bran in corn promotes satiety, helping you feel full longer.
The fibre in corn also acts as a prebiotic, feeding and fueling the growth of beneficial gut bacteria.
There’s more. Sweet corn serves up niacin, folate, vitamin C, magnesium and potassium.
Yellow corn also contains lutein and zeaxanthin, phytochemicals that protect vision by guarding against cataract and macular degeneration. (White corn contains very little lutein and zeaxanthin.)
Scientists speculate that consuming at least 6 mg of lutein per day is optimal for eye health; one cup of yellow corn delivers 22 per cent of that.
Nutrient information per one large ear of corn, cooked (or 1 cup/250 ml):
| Calories | 143 kcal |
| Fat | 2 g |
| Protein | 5 g |
| Carb | 31 g |
| Fibre | 3.5 g |
| Sugars | 5 g |
| Folate | 70 mcg |
| Potassium | 384mg |
| Thiamine | 0.4 mg |
| Vitamin C | 10 mg |
| Zinc | 0.8 mg |
| Niacin | 2.4 mg |
Source: Canadian Nutrient File, 2007b
Varieties
Also known as maize, corn was the main crop for North American natives, including the Mayas, Aztecs and Incas, for thousands of years. Today, corn remains one of the most abundant crops in North America.
There are countless varieties of corn that differ not only in size, taste and texture, but also colour including red, pink, black and blue. The most common varieties of corn include sweet, dent and flint, as well as varieties grown for flour and popcorn.
Sweet corn, available with white or yellow kernels, is the variety most widely eaten. In Ontario, Canada three types of sweet corn are grown: normal, sugar-enhanced and supersweet. While the sugar content of regular sweet corn varies between 9 and 16 percent, some of the sweeter types range from 14 to 44 percent.
As for Peaches and Cream corn, a favourite of many, it's often grown in backyard, small-scale gardens; it never made it to large-scale commercial production. Peaches and Cream corn is actually just a bi-colour variety of sweet corn - usually with white and yellow kernels on the same husk.
Buying
Whether you buy from a road-side stand or your local grocery store, there are a few things to keep in mind when buying fresh corn. Fully ripe sweet corn has husks that are bright green and moist. The silk at the top of the husk should be a shiny, moist and have a golden colour.
If you can, peel back part of the husk to examine the kernels and choose a cob that has plump, soft yellow colour kernels - avoid any that are discoloured or shriveled. Kernels at the top of the cob should be small; large kernels are a sign of old corn.
Fresh corn is available only for a few short months during the year, but frozen and canned corn is available year round. Canned corn usually has added salt and sugar; amounts can vary widely from brand to brand. Some brands of canned corn deliver aas much as 470 milligrams of sodium per 1/2 cup serving, while low-sodium brands have as little as 120 mg per serving. Choose a brand that is sodium-reduced or has no salt added. Most bands of frozen corn are salt-free.
Storing
Corn's natural sugars start to convert to starch immediately after picking, which means the longer corn sits after picking, the less sweet it will taste. For maximum flavour and sweetness, corn should be eaten the same day it was picked.
Alternatively, it can be stored in a cool, moist place, such as the refrigerator, for up to three days. Storing fresh corn in a cool place will help slow the breakdown of the sugars and help maintain its sweet taste. If you're traveling with fresh corn, store it in a cooler with plenty of ice.
Preparing
There are many ways to prepare corn on the cob - whether it's baking, boiling, roasting, or grilling.
Boiling
Bring a large pot of water to a boil. Add husked corn and bring back to a boil. Cook for 4 minutes, remove from heat and serve warm. Do not add salt or sugar to the water, which will toughen the corn. Alternatively, drop the corn in a pot of boiling water, cover, remove from heat and let stand for 5 minutes or until tender - remove from water and serve warm.
Baking
Preheat oven to 375°F (190°C). Strip off the husk and remove any fine silk from the corn. Wrap in foil and bake for 20 to 30 minutes, or until tender.
Grilling
Remove any silk from the top of the cob, soak corn (in the husk) for 5 to 10 minutes. Place corn on the grill and cook over medium heat for 15 minutes, or until tender. Alternatively you can peel the corn, wrap in foil and then place the corn on the grill.
Microwave
Remove most of the husk, leaving one or two layers in place. Remove the silk from the top of the husk. Place corn on a paper towel and microwave for 3 to 4 minutes. Remove from heat, and very carefully remove remaining layers of husk.
Eating
If smothering butter on hot corn on the cob is the only way you enjoy it, it's time to broaden your horizons. Here are many different (and healthy) ways to cook, season and enjoy fresh corn on the cob.
Healthy ways to enjoy
Breakfast
- Add fresh or frozen corn kernels to savoury muffin and quick breads batters.
- Make a colourful, nutrient-packed omelet with fresh corn kernels, sliced red bell peppers and baby spinach leaves.
Lunch
- Top a fresh green salad with roasted corn kernels.
- Make a satisfying mid-summer lunch by combining equal parts black beans, chickpeas, kidney beans and corn kernels. Season with a drizzle of extra virgin olive oil, freshly squeezed lime juice, minced garlic and chopped and fresh cilantro.
Dinner
- Instead of butter, season hot corn on the cob with a fresh lime juice. Just run a sliced lime up and down a warm cob of corn and sprinkle with chili powder.
- Leftover corn from the weekend barbecue? Make a delicious corn chowder and freeze for cold winter nights.
- Make a Mexican inspired stir-fry with corn kernels, black beans and sliced avocado.
Snacks
- Pass up the high-sodium microwave popcorn for home-roasted popcorn. In a large pot heat 3 tbsp (40 ml) of olive oil or canola oil and 3 popcorn kernels. When the kernels begin to pop, add 3/4-cup (175 ml) popcorn and cover. Shake the pot over the heat until popcorn stops popping. Remove from heat; season with a small amount of sea salt.
More Information
Ontario Corn Producers' Association - http://www.ontariocorn.org/
Foodland Ontario - http://www.foodland.gov.on.ca/index.html
The World's Healthiest Foods - http://www.whfoods.com/genpage.php?tname=foodspice&dbid=90
Strom's Farm - Guelph Ontario - http://www.strom.ca/index.htm
Did you know?
- One ear of corn averages 16 rows with 800 kernels.
- A bushel or corn weighs 56 pounds (25.4 kg) and contains over 72, 800 kernels. It can produce 32 lbs of starch, or 33 lbs of sweetener.
- About 60 percent of corn grown in Ontario, Canada is used for livestock.
- Of 10,000 items in the average grocery store, over 2500 use corn in some form during production, processing or packaging.