Health benefits of grapes

:nutrition-and-you.com

2012/04/10

805

Grapes are rich in polyphenolic phytochemical compound resveratrol. Resveratrol is one of powerful anti-oxidant, which has been found to play protective function against cancers of colon and prostate, coronary heart disease (CHD), degenerative nerve disease, Alzheimer's disease and viral/ fungal infections.
Resveratrol reduces stroke risk by altering the molecular mechanisms in the blood vessels. It does so firstly by reducing susceptibility of blood vessels damage through decreased activity of angiotensin (a systemic hormone causing blood vessel constriction that would otherwise elevate blood pressure) and secondly, through increased production of the vasodilator substance, nitric oxide (a beneficial compound that causes relaxation of blood vessels).
Anthocyanins are another class of polyphenolic anti-oxidants present abundantly in the red grapes. These phyto-chemicals have been found to have anti-allergic, anti-inflammatory, anti-microbial, as well as anti-cancer activities.
Catechins, a type of flavonoid tannin group of anti-oxidants found in white/green varieties has also shown to have these health protecting functions.
In addition, the berries are very low in calories. 100 g fresh grapes just provide 69 calories but zero cholesterol levels.
Grapes are rich source of micronutrient minerals like copper, iron and manganese. Copper and manganese are an essential co-factor of antioxidant enzyme, superoxide dismutase. Iron is specially concentrated more in raisins. In addition 100 g of fresh grapes contain about 191 mg of health benefiting electrolyte, potassium.
They are also good source of vitamin-C, vitamin A, vitamin K, carotenes, B-complex vitamins such as pyridoxine, riboflavin, and thiamin.

Principle	Nutrient Value	Percentage of RDA
Energy	69 Kcal	3.5%
Carbohydrates	18 g	14%
Protein	0.72 g	1%
Total Fat	0.16 g	0.5%
Cholesterol	0 mg	0%
Dietary Fiber	0.9 g	2%
Vitamins
Folates	2 µg	0.5%
Niacin	0.188 mg	1%
Pantothenic acid	0.050 mg	1%
Pyridoxine	0.086 mg	7.5%
Riboflavin	0.070 mg	5%
Thiamin	0.069 mg	6%
Vitamin A	66 IU	3%
Vitamin C	10.8 mg	18%
Vitamin E	0.19 mg	1%
Vitamin K	14.6 µg	12%
Electrolytes
Sodium	0%	1 mg
Potassium	191 mg	4%
Minerals
Calcium	10 mg	1%
Copper	0.127 mg	14%
Iron	0.36 mg	4.5%
Magnesium	7 mg	2%
Manganese	0.071 mg	3%
Zinc	0.07 mg	0.5%
Phyto-nutrients
Carotene-?	1 µg	--
Carotene--ß	39 µg	--
Crypto-xanthin-ß	0 µg	--
Lutein-zeaxanthin	72 µg	--

Selection and storage

Fresh grapes are available all around the seasons. In the store, choose those that feature plump in consistency, free from surface wrinkles with intact skin, without any cuts or cracks or leaking juice, and firmly attached to a healthy-looking green stem. Lift completely healthy-looking bunch up in the air and gently shake; loose berries, if any will fall off easily.

Buy exactly ripened berries; green grapes should have a slight yellowish hue, red types should be mostly pinkish-red, while purple and blue-black types should be deep and rich in color.

Since the fruit tend to spoil early and ferment at room temperature, they should always be stored in the refrigerator. Loosely wrap washed grapes in a paper towel and place them in a zip pouch bag set at high relative humidity. This way, they will keep fresh in the refrigerator for several days.