Safety assessment of rhamnogalacturonan-enriched carrot pectin fraction: 90-Day oral toxicity study in rats and in vitro genotoxicity studies

Abstract

The dietary fibre product examined is a pectic polysaccharide extract from carrot (Daucus carota), enriched for pectin fragments comprising mainly rhamnogalacturonan-I (RG-I) (abbreviated product name cRG-I). To assess the safety of cRG-I for use as food ingredient, repeated-dose oral toxicity and in vitro genotoxicity studies were conducted. In the subchronic toxicity study (OECD test guideline 408), Wistar Hannover rats received cRG-I at dietary levels (w/w) of 0%, 2.5%, 5% and 10% for 13 weeks. cRG-I induced no adverse effects in this study. The NOAEL was 10% in the diet (equivalent to 6.9 and 7.8 g cRG-I/kg body weight/day in male and female rats, respectively). A package of three in vitro genotoxicity tests (Ames, mouse lymphoma and micronucleus assay in human peripheral blood lymphocytes) was negative for induction of point mutation and chromosome damage. An initial Ames test showed a weak positive response in Salmonella typhimurium strain (TA1537). This response was non-reproducible and attributed to microbial contamination as subsequent tests with an irradiated batch of cRG-I including a repeat Ames test were negative. cRG-I was therefore considered to be non-mutagenic.

Keywords: Carrot fibre; Food ingredient; Genotoxicity; Pectic polysaccharide; Repeated-dose (90-day) toxicity; Rhamnogalacturonan-I.