Q. For some time my supermarket has been selling what looks like "too perfect" Alaskan crab. Can you tell me what is in these obviously man-made seafood sticks?

A. The product you describe is one of a variety of highly processed shellfish look-alikes made from fish paste, or so-called "surimi." In this case the fish paste, containing both fish and crabmeat, is extruded into continuous filaments like spaghetti, worked together to resemble crab-leg muscle, and then painted with a surface coloring.

Surimi was first produced in Japan about 900 years ago, when fishermen discovered that washing and mincing the fish, seasoning it, and then cooking it would yield a product that kept longer than fresh fish. The process has remained essentially the same throughout the centuries. In Japan today, one can find over 2,000 surimi-based creations, many of which are dietary staples.

Almost 25 years ago, the Japanese began to freeze surimi successfully. Gradually the export business swelled to over 550 tons a year, valued at $3.5 billion. While the surimi intended for domestic consumption comes from sources such as shark, sea eel and lizard fish, that sold in U.S. markets generally is made from Pacific pollock, a less expensive member of the cod family.

Mechanically deboned fish is first washed with cold water until it loses both flavor and odor. The resulting pulp is then drained, strained and mixed with sugar, salt, potassium sorbate, monosodium glutamate and starch, and frozen in slabs. To make the imitation seafood products, the manufacturers thaw the slabs, sometimes blending them with other fin fish and real shellfish. They add ingredients such as eggwhites and starch, which act as binders, and natural and artificial flavors. Finally, the mixture is molded into the desired shape.

As you might expect, the frequent washings and the addition of starches and water mean that although surimi products do provide essential nutrients, they are not nutritionally equivalent either to the fish from which they are made or to the shellfish which they imitate. Not surprisingly, there is considerable controversy over the labeling of these products.

At present some of the labels are quite clear, but many are misleading and others are downright deceptive. The Food and Drug Administration is working to establish labeling regulations that will require manufacturers to furnish consumers with the clear information necessary for informed choices. But the development of these regulations is no simple task.

Q. What is the relationship between coffee drinking and noncancerous breast cysts?

A. A large study of this issue conducted in Israel was reported recently in the Journal of the American Medical Association. It joins two other studies of similar design in finding no association between coffee drinking (or more correctly, the consumption of chemically related compounds called methylxanthines found in coffee, tea, cocoa, chocolate and cola beverages) and the occurrence of what is known as benign breast disease.

In this latest study, investigators compared methylxanthine consumption -- 87 percent of which came from coffee -- in over 700 women with benign breast disease with two groups of controls. One group included women who were hospitalized for brief periods with conditions unlikely to affect their consumption of these foods and beverages. The other was composed of neighborhood women presumed to be of the same socioeconomic status as the individuals with breast disease. The women were matched on the basis of age, country of origin and duration of residence in Israel.

Women with benign breast disease consumed, on average, 302 milligrams (mg.) of methylxanthines a day. The so-called surgical controls took in 312 mg. a day, and the neighborhood controls, 313 mg. daily. Even without sophisticated statistical measurements, it is quite clear that intakes among the three groups do not vary significantly.

Q. Does salt have any function in yeast bread except to contribute to the flavor?

A. Yes. It is possible to produce a good loaf without it, but salt does make important contributions to bread production. It both governs the activity of the yeast and strengthens the gluten in the flour.

Although it will not reach the volume of a loaf made without salt, salt-free bread dough tends to rise more quickly and is more vulnerable to overfermentation. In fact, because dough made without salt can collapse, the dough is kept quite stiff and the rising of shaped loaves is limited. Because salt slows carbon-dioxide production, the proportion of salt to flour is much lower in yeast bread than that used in making quick breads.