Strawberries
The fragrantly sweet juiciness and deep red color of strawberries can brighten up both the taste and aesthetics of any meal; it is no wonder they are the most popular berry fruit in the world. Although strawberries have become increasingly available year-round, they are at the peak of their season from April through July when they are the most delicious and most abundant.
While there are more than 600 varieties of strawberries that differ in flavor, size and texture, one can usually identify a strawberry by its red flesh that has yellow seeds piercing its surface, and the small, regal, green leafy cap and stem that adorn its crown. In addition to strawberries that are cultivated, there are also varieties that grow wild. These are much smaller in size, but feature a more intense flavor.
- Health Benefits
- Description
- History
- How to Select and Store
- How to Enjoy
- Safety
- Nutritional Profile
- References
Strawberries not only look like a fruity heart-shaped valentine, they are filled with unusual phytonutrients that love to promote your health.
Potent Antioxidant Protection from Phenols
Strawberries, like other berries, are famous in the phytonutrient world as a rich surce of phenols. In the strawberry, these phenols are led by the anthocyanins (especially anthocyanin 2) and by the ellagitannins. The anthocyanins in strawberry not only provide its flush red color, they also serve as potent antioxidants that have repeatedly been shown to help protect cell structures in the body and to prevent oxygen damage in all of the body's organ systems. Strawberries' unique phenol content makes them a heart-protective fruit, an anti-cancer fruit, and an anti-inflammatory fruit, all rolled into one. The anti-inflammatory properties of strawberry include the ability of phenols in this fruit to lessen activity of the enzyme cyclo-oxygenase, or COX. Non-steriodal anti-inflammatory drugs like aspirin or ibuprofen block pain by blocking this enzyme, whose overactivity has been shown to contribute to unwanted inflammation, such as that which is involved in rheumatoid and osteoarthritis, asthma, atherosclerosis, and cancer. Unlike drugs that are COX-inhibitors, however, strawberries do not cause intestinal bleeding.
Strawberry Phytonutrients that Promote Optimal Health
The ellagitannin content of strawberries has actually been associated with decreased rates of cancer death. In one study, strawberries topped a list of eight foods most linked to lower rates of cancer deaths among a group of over 1,000 elderly people. Those eating the most strawberries were three times less likely to develop cancer compared to those eating few or no strawberries. A study published in the Journal of Agriculture and Food Chemistry analyzed eight strawberry cultivars for their content of protective plant compounds (phenols, flavonoids and anthocyanins) and their antioxidant capacities. Although the various cultivars differed significantly in the amounts of the various beneficial compounds each contained, all cultivars (Earliglow, Annapolis, Evangeline, Allstar, Sable, Sparkle, Jewel, and Mesabi) were able to significantly inhibit the proliferation of human liver cancer cells. nterestingly, no relationship was found between a cultivar's antioxidant content and its ability to inhibit cancer cell proliferation, which suggests that this beneficial effect of strawberries is caused by other actions of their many beneficial compounds. Protection against Macular Degeneration Your mother may have told you carrots would keep your eyes bright as a child, but as an adult, it looks like fruit is even more important for keeping your sight. Data reported in a study published in the Archives of Ophthalmology indicates that eating 3 or more servings of fruit per day may lower your risk of age-related macular degeneration (ARMD), the primary cause of vision loss in older adults, by 36%, compared to persons who consume less than 1.5 servings of fruit daily. In this study, which involved over 110,000 women and men, researchers evaluated the effect of study participants' consumption of fruits; vegetables; the antioxidant vitamins A, C, and E; and carotenoids on the development of early ARMD or neovascular ARMD, a more severe form of the illness associated with vision loss. While, surprisingly, intakes of vegetables, antioxidant vitamins and carotenoids were not strongly related to incidence of either form of ARMD, fruit intake was definitely protective against the severe form of this vision-destroying disease. Three servings of fruit may sound like a lot to eat each day, but strawberries can help you reach this goal. Top your morning cereal, lunch time yogurt or cottage cheese with fresh strawberries. Dress up any green salad with sliced strawberries, slivered almonds and a splash of balsamic vinegar. For an easy, elegant dessert, blend fresh or frozen strawberries with a spoonful of honey and some soy or cow's milk or yogurt. Freeze for 20 minutes, then spoon into serving cups and decorate with a sprig of mint. Protection against Rheumatoid Arthritis While one study suggests that high doses of supplemental vitamin C makes osteoarthritis, a type of degenerative arthritis that occurs with aging, worse in laboratory animals, another indicates that vitamin C-rich foods, such as strawberries, provide humans with protection against inflammatory polyarthritis, a form of rheumatoid arthritis involving two or more joints. The findings, presented in the Annals of the Rheumatic Diseases were drawn from a study of more than 20,000 subjects and focused on who developed inflammatory polyarthritis and similar subjects who remained arthritis-free during the follow-up period. Subjects who consumed the lowest amounts of vitamin C-rich foods were more than three times more likely to develop arthritis than those who consumed the highest amounts.
In terms of traditional nutrients, strawberries emerged from our food ranking system as an excellent source of vitamin C and manganese. They also qualified as a very good source of dietary fiber and iodine as well as a good source of potassium, folate, riboflavin, vitamin B5, omega-3 fatty acids, vitamin B6, vitamin K, magnesium, and copper.
The strawberry, a fruit that features a fragrantly sweet flavor, is the most popular type of berry fruit in the world. While there are more than 600 varieties of strawberries that differ in flavor, size and texture, one can usually identify a strawberry by its red flesh that has yellow seeds piercing its surface, and the small, regal, green leafy cap and stem that adorn its crown. In addition to strawberries that are cultivated, there are also varieties that grow wild. These are much smaller in size, but feature a more intense flavor.
The most common scientific names for strawberry are Fragaria virginiana and Fragaria chilioensis.
Strawberries have grown wild for millennia in temperature regions throughout the world. They began being cultivated sometime before the Christian era and were highly prized by many ancient Romans. Yet, after the fall of Rome, they seemed to have lost their favor until they reemerged in Europe in the Middle Ages. During this time, they began to be prized again, more so for their medicinal qualities than for their culinary value. Cultivation techniques of the European varieties, which were much smaller than the American varieties, were advanced at this time, although the resulting fruits were not as sweet and fragrant as the strawberries of today, and therefore, they did not readily gain widespread popularity.
It was not until the 18th century, when coincidence and the workings of Nature's mysteries coincided, that strawberries developed into the luscious fruit we know them to be and began to be more widely appreciated. In 1714, a French engineer sent to Chile and Peru to monitor Spanish activities in these countries "discovered" a strawberry native to this region that was much larger than those grown in Europe. He brought many samples back to France, which were subsequently planted. These plants did not originally flourish well until a natural crossbreeding occurred between this species and a neighboring North American strawberry variety that was planted nearby in the field. The result was a hybrid strawberry that was large, juicy and sweet, and one that quickly grew in popularity in Europe.
The strawberry, like many other perishable fruits at this time, remained a luxury item only enjoyed by the wealthy until the mid-19th century. Once railways were built and more rapid means of transportation established, strawberries were able to be shipped longer distances and were able to be enjoyed by more people. The strawberry is now the most popular berry fruit in the world. Currently, the United States, Canada, France, Italy, Japan, Australia and New Zealand are among the largest commercial producers of strawberries.
As strawberries are very perishable, they should only be purchased a few days prior to use. Choose berries that are firm, plump, free of mold, and which have a shiny, deep red color and attached green caps. Since strawberries, once picked, do not ripen further, avoid those that are dull in color or have green or yellow patches since they are likely to be sour and of inferior quality. Medium-sized strawberries are often more flavorful than those that are excessively large. If you are buying strawberries prepackaged in a container, make sure that they are not packed too tightly (which may cause them to become crushed and damaged) and that the container has no signs of stains or moisture, indication of possible spoilage. Strawberries are usually available year round, although in greatest abundance from the spring through the mid-summer.
Like all berries, strawberries are very perishable, so great care should be taken in their handling and storage. Before storing in the refrigerator, remove any strawberries that are molded or damaged so that they will not contaminate others. Replace unwashed and unhulled berries in their original container or spread them out on a plate covered with a paper towel, then cover with plastic wrap. Strawberries will keep fresh in the refrigerator for one or two days. Make sure not to leave strawberries at room temperature or exposed to sunlight for too long, as this will cause them to spoil. To freeze strawberries, first gently wash them and pat them dry. You can either remove the cap and stem or leave them intact, depending upon what you will do with them once they are thawed. Arrange them in a single layer on a flat pan or cookie sheet and place them in the freezer. Once frozen, transfer the berries to a heavy plastic bag and return them to the freezer where they will keep for up to one year. Adding a bit of lemon juice to the berries will help to preserve their color. While strawberries can be frozen whole, cut or crushed, they will retain a higher level of their vitamin C content if left whole.
Baby foods containing berries are bereft of anthocyanins, the water-soluble plant pigments responsible not only for the blue, purple, and red color of berries, but also for many of their health benefits.
Anthocyanins are found in fresh and frozen berries, but not in processed foods.
A study published in the Journal of Agricultural and Food Chemistry found anthocyanins were almost undetectable in canned foods, bread, cereals, and baby foods containing berries, even in baby foods prepared from fruits high in anthocyanins, such as blueberries.
This may be due to anthocyanins' unique chemical structure, which renders them unstable even at a neutral pH and therefore much more susceptible to destruction during processing than other phytonutrients, such as proanthocyanidins. To give your children the full health benefits of berries, purchase fresh or frozen berries and purée them.
For some of our favorite recipes, click Recipes.
Tips for Preparing Strawberries:
Since they are very perishable, strawberries should not be washed until right before eating or using in a recipe. Do not remove their caps and stems until after you have gently washed the berries under cold running water and patted them dry. This will prevent them from absorbing excess water, which can degrade strawberries' texture and flavor. To remove the stems, caps and white hull, simply pinch these off with your fingers or use a paring knife.
Despite their perishable nature, strawberries do appear to hold up well in fruit salad if properly stored and chilled. This is good news for those of us who are pressed for time but love fresh fruit salad. And who doesn't since its a perfect addition to any meal and makes a great snack or dessert?
It's been thought that cut fruit rapidly degrades, so fruit salad, which can take 15 minutes to prepare, would have to be freshly prepared to be good, but a study published in the Journal of Agricultural and Food Chemistry has found that minimal processing of fruit-cutting, packaging and chilling-does not significantly affect its nutritional content even after 6, and up to 9, days.
In practical terms, this means that you can prepare a large bowl of fruit salad on the weekend, store it in the refrigerator, and enjoy it all week, receiving almost all the nutritional benefits of just prepared fruit salad.
Researchers cut up Strawberries, pineapples, mangoes, cantaloupes, watermelons, and kiwi fruit. The freshly cut fruits were then rinsed in water, dried, packaged in clamshells (not gastight) and stored at 41°F(5°C).
After 6 days, losses in vitamin C were less than 5% in strawberry, mango, and watermelon pieces, 10% in pineapple pieces, 12% in kiwifruit slices, and 25% in cantaloupe cubes.
No losses in carotenoids were found in kiwifruit slices and watermelon cubes. Strawberry, cantaloupe and mango pieces lost 10-15% while pineapples lost 25%.
No significant losses in phenolic phytonutrients were found in any of the fresh-cut fruit products. "Contrary to expectations, it was clear that minimal processing had almost no effect on the main antioxidant constituents. The changes in nutrient antioxidants observed during nine days at five degrees Celsius would not significantly affect the nutrient quality of fresh cut fruit. In general, fresh-cut fruits visually spoil before any significant nutrient loss occurs," wrote lead researcher Maria Gil.
A Few Quick Serving Ideas:
Add sliced strawberries to mixed green salad.
Layer sliced strawberries, whole blueberries and plain yogurt in a wine glass to make a parfait dessert.
Mix chopped strawberries with cinnamon, lemon juice and maple syrup and serve as a topping for waffles and pancakes.
Blend strawberries with a little bit of orange juice and use as a refreshing coulis sauce that goes well with poached pears.
Add strawberries to breakfast shakes to give them a more vibrant taste and texture.
Allergic Reactions to Strawberries
Although allergic reactions can occur to virtually any food, research studies on food allergy consistently report more problems with some foods than with others. It turns out that strawberries are one of the foods most commonly associated with allergic reactions. Other foods commonly associated with allergic reactions include: cow's milk, wheat, soy, shrimp, oranges, eggs, chicken, spinach, tomato, peanuts, pork, corn and beef. These foods do not need to be eaten in their pure, isolated form in order to trigger an adverse reaction. For example, yogurt made from cow's milk is also a common allergenic food, even though the cow's milk has been processed and fermented in order to make the yogurt. Ice cream made from cow's milk would be an equally good example.
Some of the most common symptoms for food allergies include eczema, hives, skin rash, headache, runny nose, itchy eyes, wheezing, gastrointestinal disturbances, depression, hyperactivity and insomnia. Individuals who suspect food allergy to be an underlying factor in their health problems may want to avoid commonly allergenic foods.
Strawberries and Pesticide Residues
Virtually all municipal drinking water in the United States contains pesticide residues, and with the exception of organic foods, so do the majority of foods in the U.S. food supply. Even though pesticides are present in food at very small trace levels, their negative impact on health is well documented. The liver's ability to process other toxins, the cells' ability to produce energy, and the nerves' ability to send messages can all be compromised by pesticide exposure. According to the Environmental Working Group's 2006 report "Shopper's Guide to Pesticides in Produce," strawberries are among the 12 foods on which pesticide residues have been most frequently found. Therefore, individuals wanting to avoid pesticide-associated health risks may want to avoid consumption of strawberries unless they are grown organically.
Strawberries and Oxalates
Strawberries are among a small number of foods that contain measurable amounts of oxalates, naturally-occurring substances found in plants, animals, and human beings. When oxalates become too concentrated in body fluids, they can crystallize and cause health problems. For this reason, individuals with already existing and untreated kidney or gallbladder problems may want to avoid eating strawberries. Laboratory studies have shown that oxalates may also interfere with absorption of calcium from the body. Yet, in every peer-reviewed research study we've seen, the ability of oxalates to lower calcium absorption is relatively small and definitely does not outweigh the ability of oxalate-containing foods to contribute calcium to the meal plan. If your digestive tract is healthy, and you do a good job of chewing and relaxing while you enjoy your meals, you will get significant benefits-including absorption of calcium-from calcium-rich foods plant foods that also contain oxalic acid. Ordinarily, a healthcare practitioner would not discourage a person focused on ensuring that they are meeting their calcium requirements from eating these nutrient-rich foods because of their oxalate content. For more on this subject, please see "Can you tell me what oxalates are and in which foods they can be found?"
Strawberries and Goitrogens
Strawberries contains goitrogens, naturally-occurring substances in certain foods that can interfere with the functioning of the thyroid gland. Individuals with already existing and untreated thyroid problems may want to avoid strawberries for this reason. Cooking may help to inactivate the goitrogenic compounds found in food. However, it is not clear from the research exactly what percent of goitrogenic compounds get inactivated by cooking, or exactly how much risk is involved with the consumption of strawberries by individuals with pre-existing and untreated thyroid problems. For more on this subject, please see "What are goitrogens and in which foods are they found?"Strawberries are an excellent source of vitamin C and manganese. They are also a very good source of dietary fiber and iodine. Plus, strawberries are a good source of potassium, folate, vitamin B2, vitamin B5, vitamin B6, omega-3 fatty acids, magnesium, copper, and vitamin K.
Strawberries also contain an array of beneficial phytonutrients, including flavonoids, anthocyanidins and ellagic acid.
For an in-depth nutritional profile click here: Strawberries.
In-Depth Nutritional Profile
In addition to the nutrients highlighted in our ratings chart, an in-depth nutritional profile for Strawberries is also available. This profile includes information on a full array of nutrients, including carbohydrates, sugar, soluble and insoluble fiber, sodium, vitamins, minerals, fatty acids, amino acids and more.Introduction to Food Rating System Chart
The following chart shows the nutrients for which this food is either an excellent, very good or good source. Next to the nutrient name you will find the following information: the amount of the nutrient that is included in the noted serving of this food; the %Daily Value (DV) that that amount represents; the nutrient density rating; and the food's World's Healthiest Foods Rating. Underneath the chart is a table that summarizes how the ratings were devised. Read detailed information on our Food and Recipe Rating System.
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1 comment:
I really found this blog to be full of great nutritional information!
Kristen Colello
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