ARS | Publication request: Processing Tangerine Tomatoes: Effects on Lycopene-Isomer Concentrations and Profile

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 22, 2007
Publication Date: August 1, 2007
Citation: Ishida, B.K., Roberts, J.S., Chapman, M.H., Burri, B.J. 2007. Processing Tangerine Tomatoes: Effects on Lycopene-Isomer Concentrations and Profile. Journal of Food Science. 72(6):C307-C312.

Interpretive Summary: Because lycopene is a powerful biological antioxidant, its delivery to humans is of major concern. Cis-Lycopene isomers, which are bent forms of lycopene, are more bioavailable than the all-trans isomer, which is a straight chain, and thus more efficiently absorbed by the digestive system. Almost all of the lycopene in Tangerine tomatoes is in the form of the tetra-cis isomer. This tomato gives us a useful food source to compare cis- and trans-lycopene isomer absorption. Tangerine tomatoes were processed into sauce at the University of California, Davis pilot plant for use in a human feeding study described in another publication. Samples were taken at several stages during processing, and carotenoids extracted and analyzed to measure the amounts of different isomers and their concentrations. We found that total lycopene concentration decreased considerably during the first step of processing, which included heating and juicing operations. Processing resulted in a large decrease in tetra-cis lycopene concentration accompanied by increases in trans- and other cis-lycopene isomers. We suggest that processing methods be studied further to avoid losses of components that are nutritionally beneficial.

Technical Abstract: Because lycopene is a powerful biological antioxidant, its delivery to humans is of major concern. Cis-Lycopene isomers are more bioavailable than the all-trans isomer and thus more efficiently absorbed. Tangerine tomatoes, whose lycopene isomeric content is almost all tetra-cis, provide a useful food source for comparing cis- and trans-isomer absorption. Tangerine tomatoes were processed into sauce in the University of California, Davis pilot plant for subsequent use in a human feeding study described in another publication. Samples were taken at several stages during processing, and carotenoids extracted and analyzed for carotenoid-isomer profiles and concentrations. Analyses showed that total lycopene concentration decreased considerably during the first step of processing, which included heating and juicing operations. Processing resulted in a large decrease in tetra-cis lycopene concentration accompanied by increases in trans- and other cis-lycopene isomers.