Contents of phenolics and carotenoids in tomato grown under polytunnels with different UV-transmission rates

Abstract

Tomato (Solanum lycopersicum L.) is among the economically most important vegetables in Europe, valued for its bioactiveproperties due to significant contents of vitamins, carotenoids, and phenolic compounds. In this study, the tomato cultivar Big BeefF1 was grown in the open field (OF) and under polytunnels in central Serbia during 3 years. Polytunnels were covered with two foils(both with 57% reduced photosynthetic active radiation, PAR) differing in UV-A and UV-B transmittance. The aim of our work wasto determine the influence of light conditions on accumulation of phytonutrients (carotenoids and phenolics) in the peel and flesh ofripe tomato fruits. The amount of effective antioxidants, caffeic acid, and quercetin (phenolics with ortho-dihydroxy substitution) inthe peel was the highest in tomato fruits grown in the OF (maximal PAR and UV-A and UV-B radiation). Moreover, the content of leafepidermal flavonoids was the highest in the OF. The content of lycopene and β-carotene in the flesh of tomato fruit was higher underthe polytunnel with higher UV-transmittance. Our results showed that selection of the right light conditions (quality and intensity) fortomato production has a significant effect on the accumulation of beneficial phenolics and carotenoids.