Influence of UV Light on Phenolic Content of Broccoli and Tomato Samples

Authors: Luthria, Devanand - Dave

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/29/2008
Publication Date: 8/9/2008
Citation: Luthria, D.L. 2008. Influence of UV Light on Phenolic Content of Broccoli and Tomato Samples. University of Delhi, June 2-7, 2008, Mumbai, India and Khon Kaen University, August 9-15, 2008, Khon Kaen, Thailand.

Interpretive Summary:

Technical Abstract: Two cultivars of tomato and broccoli samples were grown in high tunnels covered with two contrasting materials of similar thickness (0.152mm) and durability (4-year polyethylene). One material (Dura-film Super 4) blocked ultraviolet (UV) radiation (< 380 nm) and the other material (Tyco Tufflite IV) transmitted UV radiation. For broccoli, an additional set of field samples was also collected. Four sets of tomato samples and six sets of broccoli samples were collected from each cultivar grown under two or three different conditions: 1) in presence of UV light (UV+), 2) partially blocked ultraviolet light (UV-), and 3) from the field (broccoli only). All samples were assayed for total phenolic (TP) content by a colorimetric Folin-Ciocalteu assay (FC) and phenolic acids by a high performance liquid chromatography-diode array detection (HPLC-DAD) procedure. The amount of phenolic compounds extracted from both broccoli and tomato samples were from 10-20% greater when grown in presence of UV light (UV+) as compared to the high tunnel material that partially blocked UV radiation (UV-). The amount of phenolic phytochemicals in broccoli field samples were similar to those grown in high tunnels that allowed UV light (UV +). These results clearly suggest that UV light has a significant influence on the phenolic content in broccoli and tomatoes.