A large group of people descended on my house recently and expected me to feed them. The only thing I had on hand was a large turkey, frozen solid, so I thawed and cooked it in the microwave oven. As far as I know, nobody got sick, but my older sister questioned the wisdom of what I'd done. For future reference, did I get off lucky this time, or is it considered all right to cook a turkey that way?ANSWER - While you probably won't find that you achieve the same effect as you would by roasting it, you can cook a turkey, frozen or not, in the microwave quite safely. However, it's important to follow certain procedures to keep it safe. The USDA Food Safety and Inspection Service advises against stuffing turkeys that are to be microwaved because they may not get hot enough to kill all the harmful bacteria. If you do want to have stuffing, using chicken broth to moisten it and baking it in the oven will produce the same results with far less trouble than stuffing the bird.

The USDA also suggests that the bird be covered for part of the cooking period. If you have one available, a microwaveable bag is useful here. In the closed environment, the steam promotes better transfer of the heat necessary to kill any of the bacteria that might be present. Turning the turkey while cooking also helps insure adequate heat penetration. And to be absolutely sure that it's completely done, it's a good idea to check the interior temperature with a meat thermometer. It should reach 180 degrees Fahrenheit.

How long you should cook it depends not only on the bird's size but on the power of your oven, and that information is provided in the manual that came with it.

QUESTION - Why do egg yolks vary so much in color? Does it have anything to do with their nutritional value?

ANSWER - The major factor affecting the color of an egg yolk is the type of feed the hen was given. In fact, egg producers often control the amount of greens they give their birds so that they'll produce eggs in the medium color range. It's true that hens can convert the pigments in these greens to vitamin A, and a deep yellow color in the yolk serves as an indicator of that process. On the other hand, a pale yolk doesn't necessarily mean lower vitamin A levels because egg producers may give hens a ration that has vitamin A added to it. In that case, vitamin A levels in pale yolks can be just as high as those which are a much deeper color. And the color of the yolk is a similarly poor predictor of its cholesterol content.

Heredity, the sole determinant of shell color, has a relatively minor influence on the color of the yolk.

QUESTION - Recently I saw a film on training for long-distance and marathon running. It showed pictures of runners packing in huge amounts of pasta before a big event. Is this what is meant by "carbohydrate loading" or is there something more to it?

ANSWER - What you were seeing was the final step in carbohydrate loading, which extends over several days prior to an endurance event. The purpose is to maximize the body stores of glycogen, or muscle starch. When the practice was first introduced several years ago, athletes went on a carbohydrate diet and then exercised to the point of exhaustion, getting rid of the stored carbohydrate. Later, however, it was recognized that this "depletion" phase was not without side effects. Now, athletes simply load up, taking as much as 70 percent or even more of their calories from carbohydrates for several days before the event.

We should point out that carbohydrate loading is useful only for continuous endurance events lasting 90 minutes or more. Athletes who have never done it should test it first during the training period and not wait until a competition.

QUESTION - Are cod and scrod the same thing? How do they compare nutritionally?

ANSWER - Scrod is the term used to describe small young cod, that is, fish weighing up to 2 1/2 pounds. However, it may also be used to describe several other young fish, particularly haddock. And young pollock, which is slightly more dense and also contains somewhat more fat, is also sold as "scrod."

The age and size of fish doesn't affect their nutrient profiles. Whether you buy cod or young cod sold as scrod, a whole pound of fish will contain about 355 calories, nearly all from protein. The same pound of young pollock sold as scrod would have about 75 calories more, because it contains a still very modest 4 grams (less than a teaspoon) of fat. Since a pound of fish would easily serve three people, the per-person difference is insignificant.

The real trick, though, is to make sure preparation methods don't turn low-calorie fish into a high-calorie meal. One simple way to prepare any of these fish is to place them on a bed of lightly sauteed onions. Then, dust with fresh pepper and a hint of salt and coat with fat-free yogurt that has been seasoned lightly with curry powder.

Add a small amount of white wine (or optional liquid) to the baking dish and bake at 350 degrees until the fish flakes easily with a fork, about 30 minutes. The whole seasoning process adds fewer than 50 calories per serving.

1991, Washington Post Writers Group