Safety assessment of a natural tomato oleoresin containing high amounts of Z-isomers of lycopene prepared with supercritical carbon dioxide.

Background: Z-isomers of lycopene, which are abundantly present in processed tomato products, are more bioavailable than (all-E)-lycopene found predominantly in raw tomatoes. Despite extensive studies on the bioavailability and biological activities of Z-isomers of lycopene, detailed studies on their safety and toxicology are limited.

Results: The geno-, acute and subacute toxicities of tomato oleoresin that contained high amounts of lycopene Z-isomers (10.9% lycopene with 66.3% Z-isomer content) and had been prepared with supercritical carbon dioxide were investigated. The oleoresin was non-mutagenic in the Ames test with and without metabolic activation (S9 mix). The medial lethal dose (LD ) of the oleoresin in rats, as determined by a single-dose oral test, was more than 5000 mg kg body weight (bw) [361 mg (Z)-lycopene kg bw ]. In the 4-week repeated-dose oral toxicity test, rats were administered oleoresin at 4500 mg kg day [325 mg (Z)-lycopene kg bw day ]. There were no clinically significant changes with respect to vital signs, physical examination outcomes and laboratory test values during the test period.

Conclusion: Based on our findings and as supported by its long history of consumption, tomato oleoresin that contains high amounts of Z-isomers of lycopene prepared with supercritical carbon dioxide can be considered as safe for human consumption. © 2016 Society of Chemical Industry.