QUESTION: I have read about the new low-fat hamburger that one of the fast-food companies plans to market. The article said that the hamburger meat was mixed with a substance called carrageenan to take the place of fat. Could you write something about this? Thank you.

ANSWER: I really didn't know much about carrageenan until I read an article about it in Food Insight (IFIC Food Education Foundation, March/April 1991). According to this article, carrageenan is a polysaccharide (a type of sugar) derived from certain marine plants that has been used as a food for many years. For instance, it was used as early as 600 B.C. in Asia, and the Irish extracted carrageenan from a species of marine plants called Irish moss to thicken puddings. This "moss powder" was available in early American grocery stores, and recipes for Irish moss puddings were common in early regional cook books.The carrageenan used today is extracted from one of eight species of red algae. Modern food manufacturers appreciate this product because of its superior viscosity and gel-forming properties and use it to add body to frozen desserts, custards, pie fillings, whipped products, yogurts, sauces, relishes and some jellies. As a common ingredient in chocolate milk, carrageenan keeps the chocolate from separating to the bottom.

With the current trend to produce lower fat foods, scientists have been looking for products that simulate the characteristics of fat in certain meat and dairy food products. According to Dr. Dale Huffman, "When the fat content of ground beef is reduced below 10 percent of weight, many of the appealing sensory properties, such as the texture and juiciness, are lost." Carrageenan is being used to add moisture and help retain the natural meat juiciness. Since fat also adds flavor to the meat, food scientists are using "flavor enhancers" such as hydrolyzed yeast, vegetable protein or a small amount of encapsulated salt.

Using carrageenan and flavor enhancers, food scientists have produced an "all-lean" hamburger that contains 8 percent fat by weight. A 4-ounce cooked portion of this hamburger provides 130 calories, 75 of which are derived from protein and 55 from fat (42 percent fat). This compares to regular ground beef, which is 20 percent fat by weight, has 220 calories in the 4-ounce cooked portion, with 70 of the calories from protein and 150 from fat (69 percent fat). Although the "all-lean" carrageenan hamburger is still fairly fat (42 percent), it is much better than the 68 percent fat hamburger you get today.THIS WEEK'S HEALTHFUL LIFESTYLE GOALS

- Exercise. Continue the exercise program as outlined in previous columns and add another lower back exercise. From a supine position on the floor, pull first one bent knee and then the other into your chest until you feel stretch in the lower back, hold for about 10 seconds, and then relax. Then, pull both knees together and hold. Do five repetitions of each exercise.

- Diet. Try to incorporate dried beans into your diet at least once a week.