Quality Parameters, Empirical and Kinetic Models of Lycopene and Beta-carotene Bioformation in Tomatoes (Solanum lycopersicum)

This study modelled a kinetic for estimating geranyl geranyl pyrophosphate (GGPP) concentration in the carotenoid pathway in tomatoes (Solanum lycopersicon). Kinetics of bioformation of carotenoids in tomatoes of different cultivars (Cherry-Nasmata, VAR-10 and 4-lobes) at different ripening stages and conditions served as a model system in estimating the GGPP concentration in the kinetic model. Physicochemical parameters, lycopene and beta-carotene contents were assessed and compared under the two ripening conditions using standard laboratory procedures. The solid contents in the three cultivars of tomato range from 5.61% to 6.85% and 5.83% to 7.16% at field and ambient temperature ripening, respectively, the pH values were all in the acidic region. Highest lycopene and beta-carotene concentrations were observed in 4-lobes cultivar at field ripening. The obtained data subjected to empirical and kinetic modeling favoured the exponential models as a first order kinetics for both lycopene and beta-carotene bioformation in Cherry-Nasmata and 4-lobes cultivars. This suggests that beta-carotene bioformation is dependent on the pathway of lycopene in the tomato cultivars under study. The quality parameters of the tomato cultivars showed that ripening conditions have influence on their quality contents and the GGPP concentrations of some of the tomatoes were successfully estimated using the kinetic model.