Grapefruit

Grapefruit, like all citrus fruit, is a Hesperidum, or a large modified berry with a thick rind.

Why is it called a grapefruit? It doesn't look like a grape.

It is believed that the name refers to the grapelike way that grapefruit grows in clusters on a tree. Another explanation is that the premature grapefruit looks similar in shape to unripe green grapes. The grapefruit is a probably cross between a Pummelo and a sweet orange.

Vitamin C and a Lot More
Just half of a small- to medium-sized grapefruit has about 40 milligrams of vitamin C. That's a good portion of the 75 milligrams daily recommended for women and 90 milligrams for men. 

Given a choice, opt for pink or red types. For just a slight increase in calories (50 compared with 40), pink or red grapefruit offers significantly more vitamin A, beta carotene and lycopene than its paler cousin. Both types of grapefruit also offer some potassium and a gram or two of fiber.

Go for Glossy
Experts recommend choosing grapefruit that is glossy, round, smooth and heavy for its size. Avoid grapefruit with brown or soft spots. You can store uncut grapefruit at room temperature for up to a week, or leave it in the refrigerator for up to eight weeks. But if possible, serve grapefruit at room temperature -- it's juicier that way

Mixing With Drugs
Grapefruit juice can interact with some types of prescription medication. According to the Centers for Disease Control and Prevention's Fruit and Veggies Matter program, the effect of grapefruit juice was discovered by accident when researchers were trying to determine if alcohol had an effect on a particular blood pressure medication. To hide the taste of the alcohol, the scientists put it in a glass of grapefruit juice. They found the alcohol didn't have an effect, but the grapefruit juice did -- it greatly increased the medication's effects. That can be dangerous. Check with your doctor or pharmacist to be sure any prescription drugs you take aren't affected by grapefruit juice; if there's a problem, it's best to avoid grapefruit or inquire if an alternative medication is available.