During the summer months, we do a lot of barbecuing with marinated meat and chicken. What effect does marinating have on nutrient content?
ANSWER - That question hasn't been widely studied, but what evidence there is suggests that marinating food does have an impact. For instance, steaks marinated for 24 hours in a typical acid marinade of lime juice, oil, water, sugar and salt lost significant amounts of zinc and magnesium but gained sodium. The cooked meat actually contained twice as much sodium as the same cut that had been cooked without marinating. Similarly, meat soaked in beef broth also gained considerable sodium but lost iron and zinc. In other studies, marinades of soy sauce and of white wine lowered thiamin content.Probably the most practical point is that if you're trying to control your sodium intake, you should be sparing in your use of salt and salty condiments when you prepare marinades. As for the nutrient losses noted above, you can minimize them by using the marinade liquid as a sauce to be served with the meat. Remember that in the interest of safety, once these marinades have been used on raw food, they must be incorporated into a cooked sauce, never served as is.
QUESTION - I read that hard cheeses contain more calcium than soft cheeses. But are there any differences among the hard cheeses?
ANSWER - Surprisingly, some hard cheeses contain about twice as much calcium as others. For example, an ounce of cheddar, colby, edam, gouda, provolone or tilsit provides an average of 200 milligrams (mg.) of calcium. That's about one-quarter of the Recommended Dietary Allowance (RDA) for an adult. Swiss, gruyere and Romano have between 275 mg. and 300 mg. per ounce. At the high end, an ounce of Parmesan contains 390 mg.
Although Parmesan is high in calcium, in this country we tend to use it primarily as condiment, sprinkling it over a plate of spaghetti with sauce rather than eating it by the piece. When used in that way, we typically consume no more than two or three tablespoons, or about half an ounce of cheese. In Italy, however, it's often served by the piece. If you enjoy eating Parmesan in that form, it can become a major contributor to your calcium intake.
QUESTION - A friend taught me how to make yogurt cheese simply by dumping a container of low-fat yogurt into a funnel lined with a triple thickness of cheesecloth or moistened filter paper and letting it drain in the refrigerator. I now use it regularly as a substitute for fattening sour cream. But what nutrients am I throwing down the drain with the whey that I discard? Also, what's the caloric content of yogurt cheese?
ANSWER - To answer your second question first, two tablespoons of yogurt cheese made with low-fat yogurt will have about 28 calories and a single gram of fat. That's compared to 52 calories and 5 grams of fat in the same amount of sour cream. Unfortunately, the whey that you discard contains considerable nutrients, including some calcium and B vitamins, particularly riboflavin. Riboflavin, by the way, is visible to the naked eye; it is what gives the whey it's greenish cast.
Riboflavin is easily destroyed by sunlight.
1991, Washington Post Writers Group