Submitted to: Biotechnology Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 19, 1995
Publication Date: N/A
Interpretive Summary: We developed a continuous pilot plant process to produce lactulose from lactose using boric acid to achieve conversion of 75%. Initial studies were directed to determining the reaction kinetics and designing a continuous reaction system. Using physical property data and laboratory studies, developed a continuous separation process to remove most of the boric acid. Then, developed a liquid chromatography system to yield lactulose free from boric acid. Whereas lactose is a low cost byproduct of the domestic cheese industry, lactulose is a valuable, imported, pharmaceutical with world markets of $1.5 billion. All lactulose is produced outside the U.S, frequently with U.S. lactose. Developing a U.S. source for lactulose will permit the domestic dairy industry to use a low value byproduct, lactose, to compete with a high priced foreign commodity, lactulose. Ultimately, both the U.S. dairy industry and the consumer will benefit by turning domestic lactose into a valuable pharmaceutical which should reduce the price.
We developed a continuous pilot plant process to produce lactulose from lactose using boric acid to boost the conversion to about 75 percent. The process consists of three reactors (two continuous stirred tank reactors followed by a tubular reactor), pH adjustment, a crystallizer-filter-evaporator recycle initial separation section, and a chromatographic purification of lactulose to less than 1-5 ppm boric acid. The continuous process operates at 0.53 kg/min (55 percent solids) out of the initial separation section. The chromatographic separation is at the prep scale with a flow rate of 2.0 ml/min. The final product is a 55 percent solids syrup containing no detectable boric acid