No-Cal Powder May Sub for Food's Fat

 A new, no-calorie fat substitute called Z-Trim may change the adage that whatever's good for you must taste bad. Z-Trim, a bland mix of insoluble fiber made from the crushed hulls of grains, can replace the fat and some of the carbohydrates in foods such as chocolates, brownies, cheese, and ground beef.

"It represents a new generation of fat replacers," says its inventor, George E. Inglett of the U.S. Department of Agriculture's Biopolymer Research Unit in Peoria, Ill. Inglett unveiled Z-Trim on Aug. 26 at the American Chemical Society meeting in Orlando, Fla.

 Most fat replacers based on carbohydrates add calories back to the food, Inglett says. One example is a fat substitute that Inglett himself developed 6 years ago, called Oatrim. Made of a digestible fiber from oat flour, it provides 4 calories per gram--less than half the calories of fat but calories nonetheless. By contrast, Z-Trim passes through the body undigested.

 Z-Trim also differs from the notorious, no-calorie fat substitute olestra, which can cause gastrointestinal distress and sweep vitamins and carotenoids out of the body. The new substitute does not have those drawbacks, Inglett declares. He argues that to reduce their chances of developing intestinal disorders, people should actually eat more of the kind of insoluble fiber that makes up Z-Trim. Unlike olestra, however, Z-Trim cannot be used to fry foods.

"I wouldn't expect Z-Trim to have the same kinds of problems as olestra," says Margo Wootan, a senior scientist at the Center for Science in the Public Interest in Washington, D.C. "Fiber is already found in our diet, while olestra is a synthetic chemical."

 Inglett spent 3 years perfecting a multistage processing technique to produce the smooth, palatable Z-Trim from the tough hulls of corn, oats, or rice. First, he crushed the hulls in a mill with a highly alkaline solution of hydrogen peroxide, shearing the plant cells apart. Spinning the mixture in a centrifuge washed away all the peroxide and other water soluble components.

 After this treatment, the pieces were still too large, making the fiber coarse and gritty, Inglett says. But putting the material through the mill and centrifuge again made it smooth and able to absorb a lot of water. "That second whammy is what really does the job," he says. "It takes every cell and busts it to fragments."

 The result is a fine, white cellulose powder that can be made into a gel by adding water. Different concentrations of the powder yield gels that vary from a pourable liquid to a soft solid, like mashed potatoes. He can also blend powders of the different grains to vary the gel's consistency.

 There is concern that the "microbial stability" of foods containing Z-Trim hasn't been adequately tested. "Whenever you remove the lipid material and replace it with water," says Thomas H. Parliment, a flavor chemist for Kraft Foods in White Plains, N.Y., "microbes are able to grow, and you can get mold." That concern would have to be worked out before Z-Trim could be used in the food industry, Parliment says.

 If you want to replace fat in food, Inglett says, only three safe, no-calorie possibilities exist: water, air, and fiber. "You don't sell anybody air, you don't sell anybody water, but you can sell them Z-Trim."