By Craig Kahlke, Cooperative Extension
Is it just me, or has the blueberry’s billing as “superfruit” really put it on the public’s radar in recent years? Based on its powerful antioxidant content alone, demand for this tasty and healthy berry has increased strongly as of late. In fact, production of blueberries domestically has more than tripled in the past 25 years, with many more plantings coming into maturity in the near future.
In response, many regions of the country have begun or expanded plantings of blueberries to fill the demand and market window. Subsequently, blueberries are available year-round in local supermarkets with US production providing fruit for about half of the calendar year.
However, you cannot beat the flavor of locally-grown blueberries, of which the earliest varieties are available now. Sampling a handful at a farmer’s market or a roadside stand near you will make you a convert. Better yet, seek out a farm and pick your own!
Commercially offered “wild blueberries” are usually from species that naturally occur only in eastern and north-central North America. Other sections in the genus, native to other parts of the world, including western North America, South America, Europe, and Asia, include other wild shrubs producing similar-looking edible berries, such as huckleberries (North America) and bilberries (Europe). These species are sometimes called “blueberries” and sold as blueberry jam or other products.
Blueberries may be cultivated, or they may be picked from semi-wild or wild bushes. In North America, the most common cultivated species is Vaccinium corymbosum, the Northern highbush blueberry. Hybrids of this with other Vaccinium species adapted to southern U.S. climates are known collectively as Southern highbush blueberries.
So-called “wild” (lowbush) blueberries, are smaller than cultivated highbush ones and are prized for their intense color. The lowbush blueberry, V. angustifolium, is found from the Atlantic provinces westward to Quebec and southward to Michigan and West Virginia.
In some areas (Maine), it produces natural “blueberry barrens”, where it is the dominant species covering large areas. “Wild” has been adopted as a marketing term for harvests of managed native stands of low-bush blueberries. The bushes are not planted or genetically manipulated, but they are pruned or burned over every two years, and pests are actively managed.
Blueberries, along with cranberries, azaleas, and rhododendrons, actually prefer soils that are very acidic, with a low pH of 4.1-5.5. There are a few natural areas in upstate NY that have naturally acidic soil, but in most cases, soil amendments such as elemental sulfur or ammonium fertilizers must be used to get the pH to a range in which these plants will thrive. At higher pH, iron and zinc are not readily available to the plants and they will not grow well.
NUTRTIONAL INFO /HEALTH BENEFITS
Blueberries are good to excellent sources of vitamins C and K. Vitamin K is important in normal blood clotting function. Blueberries are also good sources of manganese (another antioxidant!) and fiber. A one cup serving of blueberries is only 84 calories.
And who can forget the antioxidant powers of this fruit? Antioxidants can prevent damage to your body cells or repair damage that has been done. They do this by significantly slowing or preventing the oxidative (damage from oxygen) process caused by substances called free radicals that can lead to cell dysfunction and the onset of problems like heart disease and diabetes.
Antioxidants may also improve immune function and perhaps lower your risk for infection and cancer.
In your body, the antioxidant process is similar to stopping an apple from browning. Once you cut an apple, it begins to brown, but if you dip it in orange juice, which contains vitamin C, it stays white.
These superfruits contain significant amounts of antioxidants in the form of the chemical class called polyphenols, which contain the anthocyanin pigments that produce the myriad of colors found in many fruits and vegetables.
Blueberries rank near the top of all fruits for antioxidant strength, with wild blueberries and cranberries having an ORAC value (oxygen radical absorbance capacity) that maximizes out at about 9000 per 100.
Raspberries have around 4900 ORAC units and apples average 2800. There is a wide range of ORAC values, however, based on specific varieties of the same fruit (or vegetable, seed or other edible product), and how they are prepared- for instance, there are large differences between fresh (raw), different types of cooked foods (steaming,boiling,frying,etc.) or whether it is in the form of a juice puree, etc. Regardless, eating a varied mix of fruits and vegetables prepared in different ways can be extremely beneficial.
The blueberry is one of the hardiest of berries. Chilled soon after harvest, they can last in the refrigerator about 10-14 days. To store, remove any bruised or moldy berries from the container. Rinse only when about to consume.
So why not preserve them by freezing them, for later use in smoothies, muffins, yogurt, on pancakes, etc.?
A freezing method for blueberries, as seen on http://www.ehow.com
1. Sort through the blueberries, picking out any that are moldy, soft, over-ripe, broken or otherwise imperfect. Also sort out anything that is not a blueberry, such as leaves or stems. Discard these damaged berries or other items.
2. Rinse the berries gently under cool, running water. Place them onto a layer of paper towels, then top with more paper towels. Dry the berries very gently, being careful not to bruise or damage them. Dry them as completely as possible.
3. Spread the berries in a single layer over a cookie sheet. Place the cookie sheet in the freezer, being careful not to tilt it or pour the berries off.
4. Freeze the berries for at least an hour or until they are frozen solid. Transfer the frozen berries into resealable plastic freezer bags, remove as much air as possible, seal the bags and return the bagged berries to the freezer. The frozen berries should be viable for about a year, but some folks have reported them good for nearly two years.
Recipe Courtesy of Dora Cristian, of Cornell Cooperative Extension of Monroe County
1 cup low-fat vanilla yogurt
½ cup juice
½ cup frozen berries (any kind)
½ teaspoon cinnamon (optional)
*Add ice if desired for a thicker consistency
1. Combine all ingredients in a blender.
2. Blend until smooth.
Makes 2 (1 cup each) servings, 120 calories per.
0.5 g fat, only 2% of calories from fat.
Visit your local farmer’s market, or better yet, search out a pick-your-own farm that has blueberries and other home-grown produce in your region. Locally grown produce is riper, more flavorful, nutritious, and less expensive in many cases than produce that is grown elsewhere. This may especially be true this season, with high fuel prices expected to raise the cost of produce trucked in from long-distance locations. In addition, buying local supports and sustains your local farms.
For more agriculture and nutrition information, call your local Cornell Cooperative Extension office. Go to http://cce.cornell.edu to find your local office.
The series is written by Craig Kahlke and Robert Hadad, both of Cornell Cooperative Extension. Kahlke works in fruit quality management for Cornell’s Lake Ontario Fruit Program. Hadad is a fresh market specialist with the Cornell Vegetable Program.
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