The effects of light intensity on organic acids, iron and sulfur metabolism in vegetables

Abstract

Vegetables and fruits are the essential part of balanced diet; they are good source of phytonutrients. Leafy vegetables are rich source of vitamins such as ascorbic acid, folic acid as well as minerals such as iron and sulfur. Phytochemicals have antioxidant activity and protect our cells against oxidative damage. In this study, we present how different light intensity produced by light emitting diodes (LEDs) influence the organic acid iron and sulfur metabolism in radich and tomatoes cultivated in the closed environment. Radish (Raphanus sativus L., ˊCherry Belleˊ) and tomatoes (Solanum lycopersicum ˊMicro Tomˊ) were cultivated under combinations of red (660nm) and blue (445 nm) LED lighting under different photosynthetic photon flux density (PPFD). The samples were taken from leaves. Results has shown that light intensity differently affects ascorbic acid folic acid, iron and sulfur accumulation in different growth strategy vegetables. The highest contents of organic acids microelement’s were found when vegetables were irradiated with 250 µmol m-2 s -1 PPFD and during maturity stage were irradiated with 150 µmol m-2 s - 1 . Tomatoes grown under 250 µmol m-2 s -1 and during maturity stage irradiated with 150 µmol m-2 s -1 accumulated about three times more treated investigated compounds than radish. The most favorable conditions for radish and tomatoes cultivation only under 250 µmol m-2 s -1 PPFD and illumination by lower PPFD during maturity stage. Selecting plants, which naturally accumulates nutritional important metabolites and choosing particular light intensity during vegetation, enables manipulate the metabolic response.