1. Nutritional Profile
- Energy value (calories per serving): Low
- Protein: Moderate
- Fat: Low Saturated fat: Low Cholesterol: None
- Carbohydrates: High
- Fiber: Low
- Sodium: Low
- Major vitamin contribution: Vitamin C
- Major mineral contribution: Potassium
2. About the Nutrients in This Food
Lemons and limes have very little sugar, no fat, and only a trace of protein, but they are high in vitamin C. One ounce fresh lemon juice has 14 mg vitamin C (19 percent of the RDA for a woman, 16 percent of the RDA for a man). One tablespoon fresh lemon juice has 7 mg vitamin C (9 percent of the RDA for a woman, 8 percent of the RDA for a man). One eight-gram lemon wedge has 2.7 mg vitamin C (4 percent of the RDA for a woman, 3 percent of the RDA for a man). One tablespoon grated lemon peel has 7.7 mg vitamin C (10 percent of the RDA for a woman, 9 percent of the RDA for a man). One ounce fresh lime juice has 9.2 mg vitamin C (12 percent of the RDA for a woman, 10 percent of the RDA for a man).
3. The Most Nutritious Way to Serve This Food
Fresh squeezed, in a fruit-juice drink. Fresh juice has the most vitamin C. Fruit-juice drinks (lemonade, limeade) are the only foods that use enough lemon or lime juice to give us a useful quantity of vitamin C.
4. Buying This Food
Look for: Firm lemons and limes that are heavy for their size. The heavier the fruit, the juicier it will be. The skin should be thin, smooth, and fine grained—shiny yellow for a lemon, shiny green for a lime. Deeply colored lemons and limes have a better flavor than pale ones. All lemons are egg-shaped, but the Key lime (which is the true lime) is small and round. Egg-shaped limes are hybrids.
5. Storing This Food
Refrigerate fresh lemons and limes. The lemons will stay fresh for a month, the limes for up to eight weeks. Sliced lemons and limes are vulnerable to oxygen, which can destroy their flavor and their vitamin C. Wrap them tightly in plastic, store them in the refrigerator, and use them as quickly as possible.
6. Preparing This Food
The skin of the lemon and lime are rich in essential oils that are liberated when you cut into the peel and tear open its cells. To get the flavoring oil out of the peel, grate the top, colored part of the rind (the white membrane underneath is bitter) and wrap it in cheesecloth. Then wring out the oil onto some granulated sugar, stir thoroughly, and use the flavored sugar in baking or for making drinks. You can freeze lemon and lime peel or zest (grated peel), but it will lose some flavor while frozen.
Lemons and limes are often waxed to protect them from moisture loss enroute to the store. Before you peel or grate the fruit, scrub it with a vegetable brush to remove the wax.
7. What Happens When You Cook This Food
Heating citrus fruits and juices reduces their supply of vitamin C, which is heat-sensitive.
8. How Other Kinds of Processing Affect This Food
Juice. Since 2000, following several deaths attributed to unpasteurized apple juice contami- nated with E. coli O157:H7, the FDA has required that all juices sold in the United States be pasteurized to inactivate harmful organisms such as bacteria and mold.
“Lemonade.” The suffix “ade” signifies that this product is not 100 percent juice and does not deliver the amounts of nutrients found in juice. NOTE: Commercial “pink lemonade” is plain lemonade colored with grape juice.
9. Medical Uses and/or Benefits
Antiscorbutic. Lemons and limes, which are small and travel well, were carried on board British navy ships in the 18th century to prevent scurvy, the vitamin C-deficiency disease.
Wound healing. Your body needs vitamin C in order to convert the amino acid proline into hydroxyproline, an essential ingredient in collagen—the protein needed to form skin, ten- dons, and bones. As a result, people with scurvy do not heal quickly, a condition that can be remedied with vitamin C, which cures the scurvy and speeds healing. Whether taking extra vitamin C speeds healing in healthy people remains to be proved.
10. Adverse Effects Associated with This Food
Contact dermatitis. The peel of lemon and lime contains limonene, an essential oil known to cause contact dermatitis in sensitive individuals. (Limonene is also found in dill, caraway seeds, and celery.)
Photosensitivity. Lime peel contains furocoumarins (psoralens), chemicals that are photo- sensitizers as well as potential mutagens and carcinogens. Contact with these chemicals can make skin very sensitive to light.
Aphthous ulcers (canker sores). Citrus fruits or juices may trigger a flare-up of canker sores in sensitive people, but eliminating these foods from the diet neither cures nor prevents canker sores.
11. Food/Drug Interactions
Iron supplements. Taking iron supplements with a food rich in vitamin C increases the absorption of iron from the supplement.