Determination of Cis and Trans Carotenes of Tangerine and Yellowish Tangerine Tomatoes by Micro-Thin-Layer Chromatography
1993 Volume 62 Issue 3 Pages 567-574
Details
1993 Volume 62 Issue 3 Pages 567-574
In the present study, cis and trans carotenes of recessive homozygote tt tomato lines were qualitatively and quantitatively analyzed by micro-thin-layer chromatography (m-TLC).
1. Four cultivars and 4 lines were used: 3 tangerine tomatoes (RRtt), 'Jubilee', MM-Rt and RC-Rt; 2 yellowish tangerine tomatoes (rrtt), GJ-rt and MM-rt; 2 red tomatoes (RRTT), 'Moneymaker' and 'Red Cherry', and one yellow tomato (rrTT), 'Golden Queen'.
2. The carotenes of RRtt and rrtt lines were separated into 11 spots (J1J10 and J5-2) by m-TLC on MgO: alumina: cellurose: CaSO4 (10 : 6 : 2 : 2, w/w/w/w), using the tech- nique of stepwise development of solvent mixtures, n-hexane: isopropanol: MeOH, from 100 : 2 : 0.2 (v/v/v) to 100 : 0 : 0 (v/v/v) (hexane alone).
These 11 carotenes were identified to be the mixture phytoene and phytofluene (not separated), β-carotene, ζ-carotene, proneurosporene, pro-lycopene, pro-γ-carotene, trans- neurosporene, and four distinct lycopene compounds, poly-cis -lycopene (b), poly-cis - lycopene (a), neolycopene and trans -lycopene.
3. When these carotenes were isomerized by iodine catalysis, the 11 spots were shifted to 6 spots. The chemical behavior of these isomerized carotenes was almost identical to that of the carotenes isolated from red tomatoes; namely, a mixture of phytoene and phy- tofluene and the trans forms of β-, ζ-and γ-carotene, neurosporene and lycopene.
4. The amounts of carotenes developed on m-TLC were directly measured by chromato- scanner, using standard linear regression. Tangerine tomatoes (RRtt) contained 130 142 μg total carotene•g-1 fruit fresh weight which was about twice that of red toma- toes (RRTT, 7175 μg•g-1) and 5 to 10 times that of rrtt lines (1526μg•g-1). Yellow tomato (rrTT) contained about 4μg•g-1 total carotene.
5. Recessive homozygote tt lines were characterized by a large number of cis form carotenes and a high concentration of cis and trans forms of ζ-carotenes (1944%), neurosporenes (1822%) and lycopenes (2048%). In addition, pro-γ-carotene was con- tained in a quantity similar to that of β-carotene, which suggests the presence of a new pathway leading to the formation of pro-γ-carotene in the biosynthesis of β-carotene.
