Half of a large grapefruit has 50 calories, 2 grams of fiber and 11 grams of sugar while 8 fluid ounces of grapefruit juice contains about 100 calories and 22 grams of sugar.
One serving also provides approx. 300 mg of potassium. Grapefruit also is a good source of pectin, vitamin C, inositol and bioflavonoids and a fair source of folic acid.
Grapefruit juice contains lower concentration of the B vitamin folate, thiamin and niacin than does orange juice.
Vitamin C in grapefruit juice brings along with it other potentially beneficial antioxidants and bioflavonoids. Many compounds have been proposed as active components in grapefruit juice, including both flavonoids (naringenin and naringin) and nonflavonoids (6’, 7’-dihydroxybergamottin).
The principal flavonoid in grapefruit juice is the flavanone glycoside naringin. Naringin contributes to the bitter taste of the fruit.
It is occurs in low concentrations, in the juice of mature grapefruit but in higher concentrations in segment membranes, core and peel
Red grapefruit juice also contains trace elements of the carotenoid lycopene. Lycopene has the greatest single oxygen quenching capacity (in vitro) of the dietary carotenoids.
Nutrients in grapefruit juice
