Raspberries
Raspberries are a high-fiber food with insoluble cellulose in the skin and soluble pectins in the fruit. They are a good source of vitamin C.
One-half cup fresh raspberries has four grams dietary fiber and 16 mg vitamin C (21 percent of the RDA for a woman, 18 percent of the RDA for a man).
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Fresh or thawed, with cereal for even more fiber.
Look for: Plump, shiny berries.
Avoid: Packages with juice stains or leaks suggesting crushed—and possibly moldy—berries inside.
Refrigerate fresh berries. Do not wash or handle before storing. Washing increases the possibility of mold; handling damages cells, releasing enzymes that inactivate vitamins and make the berries less nutritious.
Rinse the berries under cool running water, then drain and pick over carefully to remove all debris.
Heat dissolves the pectins in berry cells, making the berries softer. It also destroys some of the vitamin C.
Freezing. When you thaw frozen berries, some liquid leaks out, which means there is less water and more berry flesh per serving. However, freezing destroys some vitamins. A cup of frozen raspberries has twice the fiber, but less folate and vitamin C, than fresh berries.
Antiscorbutics. Foods high in vitamin C cure or prevent the vitamin C deficiency disease scurvy, characterized by bleeding gums and slow healing of wounds.
Allergic reaction. Many people are sensitive to berries including raspberries. In fact, according to the Merck Manual, berries are one of the 12 foods most likely to trigger classic food allergy symptoms: hives, swelling of the lips and eyes, and upset stomach. The others are chocolate, corn, eggs, fish, legumes (peas, lima beans, peanuts, soybeans), milk, nuts, peaches, pork, shellfish, and wheat (see wheat cereals).
Food-borne illness. Small fruits such as berries appear to be a growing source of contamination by disease-causing organisms such as E. coli O157:H7 and salmonella. Common methods of decontamination such as vigorously washing the fruit are impractical with berries because they damage the fruit. In 2007, researchers from the University of Pennsylvania delivered a report at the annual meeting of the American Society of Agricultural and Biological Engineers, describing the use of pulsed ultraviolet light to decontaminate raspberries and strawberries with no observable damage to the fruit, which would give growers and food distributors a way to make their products safer before shipping.
