Grapes
This small, round or oval fruit has a semi-translucent flesh encased by a smooth, thin skin. Grapes are typically sweet and come as seeded or seedless. Grapes are the leading fruit crop in the world. Grapes contain several nutrients which are potentially life-extending, including resveratrol. This compound is found in red wine and in grape skins.
Overview
There are three main species of grapes. They are:
- European grapes - This species accounts for more than 95 percent of the world's grapes. The varieties include Thompson, which are seedless and amber-green; Emperor, purple in color and with seeds; and the Champagne/Black Corinth, which are very small and are purple. The skins of European grapes adhere very closely to the flesh of the grape.
- North American grapes - The varieties in this category include Concord, which are blue-black in color and very large in size; Delaware, pink-red with a tender skin; and Niagra, less sweet and amber-colored.
- French hybrids - This category consists of various species developed from crossbreeding of North American and European grapes after the majority of the varieties of grapes in Europe were destroyed by a 19th Century pest. The varieties in this category are primarily used for the production of wine.
History
It is believed grapes have been eaten since prehistoric times and may have been cultivated as far back as 5000 B.C.E. Ancient Greeks and Romans revered grapes for using in winemaking. Grapes were planted in Germany in the Rhine Valley in the 2nd Century C.E. At that time, more than 90 varieties of grapes were already common.
This fruit was carried to America by Spanish explorers about 300 years ago during the Spanish mission to New Mexico. Grapes took hold in California (thanks to its climate and a lack of grape-preying insects). In the 19th Century in France, nearly all the grape crops were destroyed by an American-born insect brought accidentally to France. Agriculturists were able to save the grapes by crossbreeding some of the American varieties and the French grapes, which are still famous for wine.
Research continues today to decipher the health-promoting polyphenol compounds in the grape's skin. Grapes are commercially produced today in France, Spain, Italy, Chile, Mexico and the U.S.
Nutritional Information
The nutritional benefits of grapes are similar to those of other berries. The nutritional quality of grapes can be enhanced by also eating the seeds, which are edible in all varieties of grapes. This fruit is a very good source of vitamin B6, manganese, thiamine, potassium, riboflavin, and vitamin C. Grapes also contain resveratrol and flavonoids.
A 100-gram serving (about 2/3 cup) contains 69 calories, 0.2 grams of fat, 18.1 grams of carbohydrates, 0.7 grams of protein, 15.5 grams of natural sugars and 1 gram of fiber.
Health Benefits
Flavanoids are excellent for promoting good health. The deeper the color of the grape, the more flavonoids are contained in it. Extracts from grape seeds are used to treat varicose veins and other venous disorders. Flavonoids are extremely powerful antioxidants and have also been shown to reverse atherosclerosis.
Grapes and grape products (such as wine and grape juice) are thought to explain why the French people, who have a diet high in saturated fats and cholesterol, also have a lower risk for heart disease than Americans. The clue that helps to explain this is the frequent consumption of grapes and red wine, since both have been shown to increase the antioxidant capacity of the blood, prevent blood platelets from clumping together to form blood clots, and to protect against vascular damage.
Resveratrol belongs to a group of compounds that plants produce against environmental stressors in self defense (such as an attack by insects or microorganisms or an attack of adverse weather). Although resveratrol has been recognized to be in more than 70 plant species, the flesh of grapes is an especially good source of this compound. Not only is resveratrol an antioxidant, it has also been shown to reduce plaque build-up in the arteries. Animal studies of resveratrol also demonstrate some anti-cancer effects and anti-inflammatory action. Fresh skin from grapes contains about 5 to 10 milligrams of resveratrol per serving, while red wine concentrations range from just 1.5 to 3 milligrams per liter.
Safety
Grapes are among the foods which are known to contain pesticide residues and should be thoroughly washed before consuming.
Concord grapes contain high levels of oxalates and other varieties of grapes contain low levels. Those people who have a history of calcium oxalate containing-kidney stones should avoid or limit their consumption of this food.
Selecting and Storing
Because grapes do not continue to ripen after they are harvested, choose grapes which are plump, wrinkle-free and appear ripe. Grapes should be stored in the refrigerator after being purchased, where they will keep for several days.
Although freezing grapes detracts from their flavor, frozen grapes are a good snack for children. To freeze, wash the grapes and pat them dry. Arrange in a single layer on a cookie sheet or other flat container and place in the freezer. Once frozen, the grapes can be transferred to a heavy plastic bag and returned to the freezer for up to 6 months.
Serving Ideas for Grapes
Eat grapes by themselves or try these simple ideas:
- Juice grapes or toss into fruit salads.
- Sliced in half, grapes can enhance the visual effect (not to mention flavor!) of any green salad.
- Curries can be given a fruity taste by adding fresh grapes.
- Stewed or spiced grapes are a good addition to poached chicken breast.
References
- Holford, P.(2004). The optimum nutrition bible. London : Piatkus
- Holford, P & Lawson, S. (2008). Optimum Nutrition Made Easy How to achieve optimum health. London : Piatkus
- Murray, M.T. et al.(2005). Encyclopedia of healing foods. London : Piatkus
- Yeager, S. & Prevention Health Books. (1998). The doctors book of food remedies : the newest discoveries in the power of food to cure and prevent health problems from aging and diabetes to ulcers and yeast infections. [Emmaus, Pa.] : Rodale
Posted in Grapes
Ask a Question Or Join a Discussion
