Growing Environment Effects the Levels of Health Promoting Compounds in Tomato

Tomato (Solanum lycopersicum L.) is one of the most commonly consumed vegetables after potato and accounts for more than $2 billion annually. In the United States, more than two-thirds of commercial fresh market tomatoes are produced in California and Florida followed by Virginia. Tomato is a good source of certain health promoting compounds, such as lycopene, β-carotene, phenolic acids and ascorbic acid. These compounds have potential to reduce risk from certain types of cancer through several mechanisms. Previous studies demonstrated that not only genotype but also environmental factors can attribute to changes in levels of these compounds. In the present study, 36 tomato cultivars/genotypes were grown at three different locations in Texas (College Station, Uvalde, and Edinburg) during spring in 2015. Total soluble solids, acidity and pH were measured to characterize the quality and ripening ratios of tomato fruits. Ripening ratios (TSS/Acidity) ranged from 9.09 ± 0.35 to 22.89 ± 0.19. Fully ripe uniform tomatoes were analyzed for carotenoids and ascorbic acid using HPLC for the identification and quantification. The thermal environments’ effects on the levels of health promoting compounds were compared. The levels of lycopene ranged from 3.42 ± 0.06 mg/100g FW to 17.21 ± 0.59 mg/100g FW. The β-carotene concentrations ranged from 0.006 ± 0.004 mg/100g FW to 0.29 ± 0.01 mg/100g FW. The ascorbic acid levels ranged from 2.75 ± 0.01 mg/100g FW to 17.55 ± 0.6 mg/100g FW. Our recently released cultivar TAM Hot-Ty was grown in 3 locations contained the highest level of lycopene at Edinburg, where the highest average temperature was 28℃ during the last month of ripening. However the lowest level of ascorbic acid was measured under the same conditions. This high temperature effect was also evident in a commercial variety, Tasti-Lee, grown in 3 locations. These results illustrate that the effect of growing environment in Texas could be considered as one of critical factors for desirable bioactive compounds in tomato fruits.