Use enzymes to catalyze the synthesis of low-calorie triglycerides.

USDA/ARS scientists (Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038) have developed a process that uses enzymes to produce reduced-calorie synthetic triglycerides. The process uses lipases from Geotrichum candidum or Candida rugosa as catalysts. These lipases are highly fatty-acid-specific, and the reaction is carried out at moderate temperatures.

This technology can be used in several interesting applications, including coatings and specialized fats. You could start with natural fats and convert them to low-calorie fats that have the organoleptic properties of the natural materials.

Researchers are able to make triglycerides using this technique when the substances have medium- or short-chain fatty acids at the two and one primary chemical positions, and an unsaturated fatty acid with a chain length of at least 18 carbons at the remaining primary position. One such synthetic triglyceride, monobehenoyldioctoyl-glycerol, is available commercially and has been incorporated into low-fat foods. But it's synthesized using the conventional process. ARS scientists realized the need to develop a method that avoids undesirable high temperatures, the formation of byproducts or the use of costly starting materials.

It's possible to synthesize triglycerides that are only partially absorbed during human digestion, reducing actual calorie intake to about half that of the natural materials. These synthesized triglycerides must be free of byproducts if they are to be used in foods. They must have specific physical properties and melting points. Conventional synthesis uses high temperatures and involves the simultaneous removal of water to form a triglyceride from the starting materials. Other alternative processes are not as attractive because they form byproducts, or the starting materials they use are expensive.

Introducing short- and/or medium-chain fatty acids to a triglyceride molecule enhances the nutritional value of food products containing the triglyceride. These fatty acids are powerful energy sources that are readily absorbed and digested. Moreover, they do not contribute directly to serum cholesterol or body fat.

Further information. Thomas Foglia; phone: [phone]; fax: [phone]; email: [e-mail]. Licensing: Stephen H. Feairheller, Technology Transfer Coordinator; phone: [phone]; fax: [phone]; email: [e-mail].