Nutritional Assessment in Humans and Rats of Leucrose [D-glucopyranosyl-α(1 → 5)-D-fructopyranose] as a Sugar Substitute

Abstract

Leucrose [D-glucosyl-alpha(1----5)-D-fructopyranose], prepared by an enzyme-catalyzed transglycosidation from sucrose with greater than 99% purity, has previously been shown to be noncariogenic and was found in the present study to be apparently easily digestible when given to humans as a single oral dose of 100 g, or when fed to rats at a level of 35 g/kg body wt daily. Weanling rats fed a 25% leucrose diet grew as well as rats fed a diet containing 25% sucrose or corn starch. When 1 g of leucrose was given intravenously to adult rats, 70% of this disaccharide was excreted in the urine within 24 h, and feeding and drinking behavior of the rats was not altered. No adverse effects on their general health were observed. The substrate properties of leucrose for alpha-glucosidase from yeast and for carbohydrases from human jejunal mucosa were determined, and these data were then compared with those of maltose and sucrose. The cleavage rate of leucrose in vitro by human digestive carbohydrases was 31% that of maltose and 63% that of sucrose. Hydrogenated leucrose (leucritol) was cleaved 10 times slower, with a Michaelis constant close to that of leucrose. Blood glucose and fructose profiles in humans given leucrose per os tended to be lower than those in humans given sucrose, while insulin and C-peptide profiles were unaltered.

Cariological Assessment of Leucrose [D-Glucopyranosyl-α(1→5)-D-Fructopyranose] as a Sugar Substitute

“…According to Ziesenitz et al [1989], leucrose is well digestible and metabolized in humans and rats, where the a(l -5)-glycoside bond does not resist en zymatic attack by carbohydrase complexes of the in testine.…”

Safety Evaluation Studies of Leucrose

“…The T/2 (elimination half-life) of fructose was slightly longer after leucrose administration compared to the findings after sucrose, and this difference was also statistically significant. There were no statistically significant differences in the peak blood levels, AUCs, and T/2s for insulin and C-peptide after either leucrose or sucrose administration (Ziesenitz et al, 19896).…”

“…The relative organ weights of stomach and cecum with contents in leucrose-fed rats were lower than those of rats fed cornstarch, and these differences were statistically significant. There were no differences between the leucrose-fed and sucrose-fed groups (Ziesenitz et al, 19896).…”

“…Leucrose was cleaved relatively slowly by a-glucosidase but not by p-fructosidase of yeast, but quite rapidly by carbohydratase complexes prepared from human jejunal mucosa, the V,,, being 63% of that of sucrose (Ziesenitz et al, 19896).…”

“…Rats were observed for 4 days. Approximately 70% of the injected disaccharides were excreted in the urine within 24 h. No glucose or fructose were detected in the urine (Ziesenitz et al, 19896).…”