Citrus Fruit Citrus X paradisi

First described in 1750 by Griffith Hughes the grapefruit was defined by the botanist James MacFayden as a natural sport of the pummelo (or pomelo). It was later discovered to be a cross between the pummelo and the orange. The name is believed to originate with the fruit's habit of growing in clusters of up to 20, reminscent of the grape.

The tree reaches a height of around 20 feet, and bears small white flowers. The fruit normally has a bright yellow peel with a pale flesh, and ranges in size from four to six inches in diameter, although some varieties are more oval in shape. The tree is highly versatile, comfortable in a wide range of soils, from acidic sandy clays to the alkaline soils of California. In recent times, sweeter varieties have been introduced, in addition to pink-fleshed fruit favoured for brightening up the breakfast table or salad bowl.

The fruit was originally considered inedible because of its relative bitterness, and many trees were cut down before the public started to develop a taste for them in the 1900s. Florida and California remain the most important growing areas in the States, although the fruit is also exported from the West Indies, South America and Israel, and has become an important commercial crop.

Grapefruit keeps well at about 18ยบ C for a week or more, but prefers the lower temperatures in the fridge. To slow moisture loss, fruits for marketing are washed and waxed as soon as possible after harvest.

In addition to its use as a whole fruit, the juice has become very popular for straight drinking as well as in commercial blends and alcoholic drinks.

The peel yields an oil used in aromatherapy, and is used to relieve stress, migraine, headache and PMS.

Caution: You should not apply this oil topically before exposure to bright sunlight.

Grapefruit juice also has effects on several prescription medicines - see that write-up for details. Thanks, Gritchka for pointing that out!

Aromatherapy is not a substitute for medical diagnosis or treatment. If you have a health condition, consult your physician. If you are pregnant or breast-feeding, consult your doctor before using any aromatherapy products. Do not take essential oils internally. Keep essential oils and all aromatherapy products out of the reach of children. -

Thanks to anthropod for pointing me to pomelo.

A Discussion of Its Nutritional and Medical Benefits

Large citrus fruit with a bitter yellow or pinkrind and inner skin, and with highly flavorful somewhat acidic pulp; from an evergreen or semi-evergreen tree (Citrus paradisi). A valuable source of nutrients, the grapefruit -- along with its cousin ugli fruit (Citrus tangelo), a cross between the grapefruit and the tangerine -- are beloved for their striking, tart taste and juicy pulp. The following discussion will focus on its often overlooked nutritional and medical benefits. Please note that the ingestion of grapefruit may conflict with a number of drugs; see Medical Indications below.

Purchase and Storage

To locate particularly juicy grapefruit, search for firm fruit that seems heavy for its size. A slightly greenish tint does not indicate under-ripeness; instead, it means the fruit will be high in sugar content. Most grapefruit, however, have a yellow skin that should be thin, smooth, and fine-grained. Ugli Fruit gives the impression of being rotten (misshapen, splotched) though they are pleasant in taste, usually mellower in fragrance than a grapefruit. Avoid puffy skin, or a lower weight than would be expected for its size: it is most likely dry inside.

Grapefruit is, expectedly, best stored at room temperature for a maximum of one week. Grapefruit juice may be refrigerated in a tightly closed glass bottle with very little air space at the top. By storing it this way, oxygen is not permitted to penetrate the fruit; oxygen destroys vitamin C content. Most plastic bottles are oxygen-permeable. Grapefruit juice can hold its vitamin C content for several weeks when properly stored and refrigerated.

Commerical Grapefruit Juice

Vitamin C being the most readily available nutrient in the grapefruit, its preservation during commercial preparation is of utmost importance. Commercial flash-freezing preserves up to 95% of the vitamin C in fresh grapefruit juice. Canned juice will lose, on the average, only 2% of its vitamin C, while cartons of prepared, pasteurized juice lose up to 20% because they are sold in plastic or waxed-paper cartons that allow oxygen flow.

Commercial pasteurization is a process which halts the conversion of sugar to alcohol; it protects juices from harmful bacteria and mold contamination. Since 2000, following several deaths attributed to unpasteurized juice containing E. Coli (O157:H7), the FDA requires that all vegetable and fruit juices be pasteurized.

Medical Use and Benefits

Lowering the rise of heart attack.
When researchers at the University of North Carolina (Chapel Hill, 1997) attempted to confirm evidence that beta-carotene (antioxidant pigment found in fruits and vegetables) lowers heart attack risk, EURAMIC data confirmed that indeed lycopene was the protective agent. Lycopene works in coordination with polyunsaturated fats. Though all fruit carries some amount of lycopene, grapefruit has the highest concentration among citrus fruit. According to the Chapel Hill study, its benefit is most apparent among people whose body composition was more than 16% in polyunsaturated fat.

Prevention of some cancers.
Grapefruit contains a substance called D-limonene - a monoterpene, aromatic compound found in citric oil - that reduces the risk of cancer by: preventing the formation of carcinogens in the body; blocking cancer-causing substances from reaching or reacting with sensitive body tissue; and by inhibiting the transformation of healthy cells to malignant ones.

Healing of Wounds
The body requires that vitamin C be present to convert amino acid proline into hydroxyproline (component of collagen) which forms skin, tendons, and bones. A healthy amount of hydroxyprolin, then, prevents and remedies the illness scurvy - the result of inadequate amount of vitamin C - and allows the body to more easily heal its wounds.

Additionally, grapefruit drastically improves the body's ability to absorb iron; this is helpful for the elderly whose diet may require the ingestion of iron supplements.

Medical Indications

Consumption of grapefruit or grapefruit juice has been shown to conflict with the following medications:

  1. Aspirin or other anti-inflammatory drugs (NSAIDS) such as ibuprofen, naproxen, and others. Citrus fruit may intensify the drug's ability to irritate the stomach and cause gastric bleeding.

  2. Antihistamines (used for treating cold symptoms and allergic reactions such as hay fever), anticoagulants, benzodiazepines (tranquilizers, sleep medications), calcium channel blockers (blood pressure medication), cyclosporine (immunosuppressant drug used in organ transplants), theophylline (asthma medication).
    1. The consumption of grapefruit (juice) appears to reduce the amount of these drugs that the body can metabolize and eliminate.
    2. While it is not yet known (1999) what chemical in grapefruit is responsible for this conflict, a strong possibility is bergamottin, a naturally occuring chemical known to inactivate cytochrome P450 3A4, which, as a digestive enzyme, converts many drugs to water-soluable substances which can be flushed out by the body.

Grapefruit is delicious when broiled or poached - especially for festive occasions, such as Thanksgiving or holiday feasts - and served with a moderate amount of brandy or wine in the fruit, and topped with a cherry.

Nutritional Profile:

Energy value (calories per serving): low
Protein: low
Saturated fat: low
Cholesterol: none
Carbohydrates: high
Fiber: moderate to high
Sodium: low
Major vitamin contribution: vitamin A, vitamin C
Major mineral contribution: Potassium

Kohlmeier, Leonard; et. al. "Lycopene: The New Heart Attack Preventer". American Journal of Epidemiology. October, 1997.
Rinzler, Carol Ann. The New Complete Book Of Food: A Nutritional, Medical, and Culinary Guide. New York: Checkmark Books, 1999.

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