1. Nutritional Profile
- Energy value (calories per serving): Low
- Protein: Low
- Fat: Low Saturated fat: Low Cholesterol: None
- Carbohydrates: High Fiber: Very high Sodium: Low
- Major vitamin contribution: Vitamins A, folate, vitamin C
- Major mineral contribution: Potassium
2. About the Nutrients in This Food
Papayas (a.k.a. paw-paws) are high in soluble dietary fiber (gums and pec- tins) with moderate amounts of vitamin A, as well as an excellent source of the B vitamin folate and vitamin C.
Half of one five-inch long papaya has 2.8 g dietary fiber, 1,663 IU vitamin A (22 percent of the RDA for a woman, 56 percent of the RDA for a man), 58 mcg folate (15 percent of the RDA), and 94 mg vitamin C (1.3 times the RDA for a woman, 100 percent of the RDA for man).
Unripe papayas and the leaves of the papaya plant contain a papain, a proteolytic (protein-dissolving) enzyme that breaks long protein molecules into smaller fragments. You can tenderize meat by cooking it wrapped in papaya leaves or by dusting it with a meat tenderizer of commercially extracted papain dried to a powder. (Soybeans, haricots verts, garden peas, broad beans, wheat flours, and egg white all contain proteins that inacti- vate papain.)
3. The Most Nutritious Way to Serve This Food
4. Buying This Food
Look for: Medium-size, pear-shaped fruit whose skin is turning yellow. The yellower the skin, the riper the fruit. Papayas ripen from the bottom up, toward the stem. Always look for fruit that is yellow at least halfway up.
5. Storing This Food
Store papayas at room temperature until they are fully ripe, which means that they have turned golden all over and are soft enough to give when you press the stem end.
Store ripe papayas in the refrigerator.
6. Preparing This Food
Wash the papaya under cool running water, then cut it in half, spoon out the seeds, and sprinkle it with lemon or lime juice.
The seeds of the papaya taste like peppercorns. They can be dried and ground as a seasoning or simply sprinkled, whole, on a salad.
7. How Other Kinds of Processing Affect This Food
Extraction of papain. Commercial meat tenderizers contain papain extracted from fresh papaya and dried to a powder. The powder is a much more efficient tenderizer than either fresh papaya or papaya leaves. At the strength usually found in these powders, papain can “digest” (tenderize) up to 35 times its weight in meat. Like bromelain (the proteolytic enzyme in fresh pineapple) and ficin (the proteolytic enzyme in fresh figs), papain breaks down proteins only at a temperature between 140°F and 170°F. It won’t work when the temperature is higher or lower.
8. Medical Uses and/or Benefits
Lower risk of
some birth defects. Up to two or every 1,000 babies
born in the United States each
year may have
cleft palate or a neural
tube (spinal cord) defect
due to their mothers’ not having gotten adequate
amounts of folate during pregnancy. The current RDA for folate is 180
mcg for a woman and 200 mcg for a man, but the FDA now recommends 400 mcg for a woman
who is or may become
a folate supplement before becoming
nant and through the first two months of pregnancy reduces the risk of cleft palate; taking folate through the entire pregnancy reduces the risk of neural tube defects.
Possible lower risk of heart attack. In the spring of 1998, an analysis of data from the records for more than 80,000 women enrolled in the long-running Nurses’ Health Study at Harvard School of Public Health/Brigham and Women’s Hospital, in Boston, demonstrated that a diet providing more than 400 mcg folate and 3 mg vitamin B6 daily, either from food or supple- ments, might reduce a woman’s risk of heart attack by almost 50 percent. Although men were not included in the study, the results were assumed to apply to them as well.
However, data from a meta-analysis published in the Journal of the American Medical Association in December 2006 called this theory into question. Researchers at Tulane Univer- sity examined the results of 12 controlled studies in which 16,958 patients with preexisting cardiovascular disease were given either folic acid supplements or placebos (“look-alike” pills with no folic acid) for at least six months. The scientists, who found no reduction in the risk of further heart disease or overall death rates among those taking folic acid, concluded that further studies will be required to determine whether taking folic acid supplements reduces the risk of cardiovascular disease.
9. Adverse Effects Associated with This Food
Irritated skin. Because it can break down proteins, papain (and/or fresh papayas) may cause dermatitis, including a hivelike reaction. This is not an allergic response: it can hap- pen to anyone.
10 Food/Drug Interactions
Monoamine oxidase (MAO) inhibitors. Monoamine oxidase inhibitors are drugs used to treat depression. They inactivate naturally occurring enzymes in your body that metabolize tyramine, a substance found in many fermented or aged foods. Tyramine constricts blood vessels and increases blood pressure. One by-product of papain’s breaking up long-chain protein molecules to tenderize meat is the production of tyramine. If you eat a food such as papain-tenderized meat while you are taking an MAO inhibitor, you cannot effectively eliminate the tyramine from your body. The result may be a hypertensive crisis.