Enhanced bioavailability of lycopene when consumed as cis-isomers from tangerine compared to red tomato juice, a randomized, cross-over clinical trial

Abstract

Scope: Tangerine tomatoes (Solanum lycopersicum) are rich in tetra-cis-lycopene resulting from natural variation in carotenoid isomerase. Our objective was to compare the bioavailability of lycopene from tangerine to red tomato juice, and elucidate physical deposition forms of these isomers in tomatoes by light and electron microscopy.

Methods and results: Following a randomized cross-over design, subjects (n = 11, 6 M/5 F) consumed two meals delivering 10 mg lycopene from tangerine (94% cis) or red tomato juice (10% cis). Blood was sampled over 12 h and triglyceride-rich lipoprotein fractions of plasma were isolated and analyzed using HPLC-DAD-MS/MS. Lycopene was crystalline in red tomato chromoplasts and globular in tangerine tomatoes. With tangerine tomato juice we observed a marked 8.5-fold increase in lycopene bioavailability compared to red tomato juice (p < 0.001). Fractional absorption was 47.70 ± 8.81% from tangerine and 4.98 ± 1.92% from red tomato juices. Large heterogeneity was observed among subjects.

Conclusion: Lycopene is markedly more bioavailable from tangerine than from red tomato juice, consistent with a predominance of cis-lycopene isomers and presence in chromoplasts in a lipid dissolved globular state. These results justify using tangerine tomatoes as a lycopene source in studies examining the potential health benefits of lycopene-rich foods.

Trial registration: ClinicalTrials.gov NCT01696773.

Keywords: Bioavailability; Carotenoids; Chromoplast; Tangerine tomato; Tetra-cis-lycopene.

Conflict of interest statement

The authors have no conflicts of interest to declare.

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Figures

Figure 1

Photographs of red (A1) and tangerine (Solanum lycopersicon L. hybrid FG10-314) tomatoes (B1) with corresponding light micrographs at 400× magnification of fresh red tomato (A2) and tangerine tomato (B2) mesocarp. Arrows and arrowheads denote crystalline and non-crystalline carotenoid containing structures, respectively.

Figure 2

Transmission electron micrographs of fresh red tomato (A) and tangerine tomato (B, C) mesocarp. Arrows: crystal (remnants), m: mitochondrion, pg: plastoglobules, w: cell wall, #: internal membranes

Figure 3

Post-prandial absorption of total lycopene (cis + trans) from tangerine (▲) and red (▪) tomato juices. The 10 mg dose of lycopene resulted in TRL concentrations (average ± SEM) of 690.9 ± 117.8 nmol·hr/L from tangerine tomato juice and 81.6 ± 32.1 nmol·hr/L from red tomato juice, making lycopene from tangerine tomatoes, on average, 8.5 times more bioavailable than lycopene from red tomatoes.

Figure 4

HPLC-MS/MS chromatogram of a 6 hr TRL after the consumption of tangerine tomato juice. HPLC-DAD-MS/MS parameters and peak labeled are given in Table 2.

Figure 5

Post-prandial absorption of 44.9 mg phytoene (A), 13.9 mg phytofluene (B), 29.3 mg ζ-carotene (C) and 6.26 mg neurosporene (D) which are found in substantial concentrations in tangerine tomato juice.