Toxicological profile of carboxymethyl inulin

Abstract

Carboxymethylinulin (CMI), formed by carboxylation of a natural carbohydrate obtained from the chicory plant, is particularly effective in sequestration of hard water cations, and thus serves as a unique anti-scalant which could find uses in food processing. A series of toxicological studies has been performed to investigate its toxiciologic properties following repeated exposure, possible sensitization, and its potential to elicit genotoxic activity; all studies conformed to internationally accepted safety test guidelines currently in force. Subacute (4-week) oral toxicity was investigated in groups of rats exposed via gavage to 0, 50, 150 and 1000 mg/kg/day CMI. No treatment-related effects were observed in body weight, food consumption, mortality, hematology, clinical blood chemistry, organ weights or gross or microscopic pathology up to the highest dose (1000 mg/kg/day) tested. Motor activity, as observed in a functional observation battery, was elevated in high-dose females, and is not considered of significance toxicologically. Lack of adverse toxicity seen with CMI at this dosage is consistent with a similar lack of significant toxicity exhibited by other dietary carbohydrates (sorbitol, sucrose, glucose), oligofructoses (inulin/FOS) and carboxylated cellulose in repeated-dose rat studies at approximately the same dosage. No evidence of dermal sensitization was observed in groups of guinea pigs following CMI testing by the Magnusson–Kligman maximization test methodology. No mutagenic activity was observed when CMI was tested in four Salmonella strains—TA1535, TA1537, TA98 and TA100—or in Escherichia coli WP2uvrA bacterial point mutation assays or in an in vitro Chinese hamster ovary cell chromosomal aberration assay. The results obtained in the present study with CMI are consistent with similar data derived on numerous dietary carbohydrate fibers generally recognized as safe in the human diet.