Biobased method of producing mannitol
Mannitol is a valuable bodying agent, preservative and diabetic-friendly sweetener.
31/03/05 Scientifically described as a sugar alcohol, mannitol is a minty-tasting ingredient found in many foods and boasts fewer calories than table sugar.
Though made by some plants and algae, mannitol is commercially produced by chemical means. In February, however, the Agricultural Research Service (ARS) obtained a patent (US 6,855,526, B2) on a method that weds nature with modern technology. ARS chemist Badal Saha calls his method "biobased" because it involves feeding high-fructose corn syrup to the bacterial species Lactobacillus intermedius in a deep-tank fermentor. There, over several hours' time, the bacteria convert 72 percent of the syrup into mannitol.
Mannitol, to L. intermedius, is little more than a metabolic waste product. But to food processors, mannitol is a valuable bodying agent, preservative and diabetic-friendly sweetener, according to Saha, with the ARS National Center for Agricultural Utilization Research at Peoria, Ill.
Mannitol also has pharmaceutical and medical uses, such as an osmotic diuretic and a hypertension treatment. Manufacturers traditionally produce mannitol by subjecting a 50-50 mixture of fructose and glucose to a nickel catalyst and high-pressure hydrogenation. Besides producing chemical wastes, the process is time-consuming and converts only 25 percent of these sugars to mannitol, sold for around $3.25 a pound.
Since 2002, Saha has collaborated with zuChem, Inc., of Chicago, Ill., to scale-up and refine the approach under a cooperative research and development agreement. Last fall, zuChem successfully petitioned the Food and Drug Administration to approve mannitol produced by microbial fermentation. Saha's research reflects the ARS center's overarching mission of creating new, value-added markets for agricultural commodities, especially from corn and soybeans.
ARS is the U.S. Department of Agriculture's chief scientific research agency.
