DEAR DR. BLONZ: My grandmother used to encourage us to eat the inner white part of the orange skin, saying that it is a secret part of the food that has special qualities. Dutifully, I have followed this advice for a lifetime. Finally, realizing that the science behind nutrition was not as well known in her day, I have come to question the advice’s worth. What, if anything, is the value of this part of the orange? -- S.N., Lombard, Illinois
DEAR S.N.: Your grandmother’s advice may not have been drawn from research findings of the day, but it does reflect an intuitive appreciation for citrus fruits, and whole foods in general.
The entire orange contains a number of naturally occurring compounds that have been associated with disease prevention in humans. But please note that simply because a substance can be found in a food, that doesn’t mean there is enough of it to have a significant beneficial effect in our bodies. These are compounds that evolved to protect the fruit’s seeds, as well as the flesh that the seeds rely upon for sustenance until they get their first sprouts into the sun and begin producing their own energy.
Aside from the vitamin C that we associate with citrus, there are a number of substances in the peel and in the white inner portion, or albedo, of the citrus peel. The list includes bioflavonoids, limonene, glucarate, pectin and soluble fiber. If you consume the outer part of the peel, expect it to contain residues from any sprays used by the grower -- so select your citrus provider carefully and scrub the fruit before eating. Citrus zest is quite flavorful and is often used for culinary purposes, but only use zest from well-washed, organically grown fruit.
Other fruits and vegetables offer similar types of protective substances, but science is still in the discovery stage about their range of potential health benefits for us -- along with how they might work together, and what effective doses would be. I salute your grandmother’s whole-food wisdom.
DEAR DR. BLONZ: There are many half-and-half products in my dairy case. Some are pasteurized, and others are ultra-pasteurized. What is the difference? -- D.C., San Jose, California
DEAR D.C.: Pasteurization and ultra-pasteurization are heat treatments designed to reduce the presence of potentially harmful microorganisms. The two differ in the amount and duration of heat used.
Pasteurization heats a dairy product to 160 degrees F for 15 seconds, while ultra-pasteurization heats the product up to 280 degrees F for up to 3 seconds. The higher heat used in ultra-pasteurization eliminates more bacteria and results in a more shelf-stable product. Once opened, however, both types of products require refrigeration.
Ultra-pasteurization is not widely used because the high heat can affect flavor, so the process is usually reserved for products such as half-and-half or whipping cream. However, ultra-pasteurized milk can be found in remote areas, or in stores that don’t sell a high volume of dairy products.
Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to email@example.com. Due to the volume of mail, personal replies cannot be provided.