(32) Changes in Functional Phytochemicals in Response to Altered Light Environments

Abstract

Numerous recent epidemiological studies have reconfirmed the old wisdom that consumption of fruits and vegetables play an important role in maintaining a healthy life. As a result, the role of fruits and vegetables in preventing the onset of chronic diseases is being established in the wake of epidemic-level health problems. The majority of evidence links various antioxidant phytochemicals in fruits and vegetables to the reduction in chronic diseases. Various methods are being investigated to enhance functional phytochemicals in fruits and vegetables, but, our knowledge on how these methods affect functionally important phytochemicals is relatively limited at this point. Environmental factors have been shown to affect certain phytochemicals and we are investigating if changing the spectral irradiance and composition in the growing environment can improve functional phytochemicals in food crops. In the present work, we investigated the role of irradiance on functionally important phytochemicals in selected lettuce (green and red) and tomato cultivars. Preliminary results show that in lettuce, high irradiance (500 vs. 250 μmol·m-2·s-1) increased total phenolic content, anthocyanin content, red coloration, and over all antioxidant capacity. Irradiance levels used in this study did not affect functional phytochemical levels in tomato fruit. High irradiance decreased the ß-carotene content in lettuce cultivars, but lycopene levels in tomato were not affected by irradiance.