Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/8/2014
Publication Date: 3/15/2014
Citation: Du, W., Avena Bustillos, R.D., Breksa III, A.P., McHugh, T.H. 2014. Effect of UV-B light on total soluble phenolic contents of various whole and fresh-cut specialty crops. Postharvest Biology and Technology. 93:72-82. DOI: 10.1016/j.postharvbio.2014.02.004.
Interpretive Summary: A comprehensive and systematic study of the effect of ultraviolet-B (UV-B) light (a form of ultraviolet light found in sunshine) exposure on total soluble phenolic contents (TSP) of commonly consumed whole and precut fruits and vegetables has been conducted in this study. The study evaluated the effect of UV-B exposure as a post harvest treatment to enhance the TSP (water soluble antioxidants) of various whole and fresh-cut specialty crops. We demonstrated that it is possible to get substantial increases in TSP of selected specialty crops and elucidated the potential of using UV-B light exposure as an additional processing step on selected specialty crops to enhance their soluble phenolic contents. Basic knowledge for this innovative technology that allows the enhancement of nutritional quality of specialty crops has been generated.
Technical Abstract: BACKGROUND: The effect of ultraviolet-B (UV-B) light treatment on total soluble phenolic contents (TSP) of various whole and fresh-cut specialty crops was evaluated. Whole fruits (strawberries, blueberries, grapes), vegetables (cherry tomatoes, white sweet corn) and root crops (sweet potatoes, colored potatoes), and fresh-cut fruit, vegetables and root crops (apple wedge, iceberg lettuce, broccoli floret and stem, and sliced radish, daikon, and parsnip) were treated with increasing UV-B dose levels and following incubation to allow for the samples to respond, TSP levels were measured. RESULTS: The changes in TSP were tissue-dependent. Whole grapes, blueberries, pink and red cherry tomatoes, white sweet corn, colored potatoes and sweet potatoes did not benefit from UV-B exposure. Strawberries showed a slight, but significant increase in TSP at the highest UV-B dose. UV-B exposure did not affect TSP of apple wedge, broccoli floret and stem, sliced radish and daikon after incubation. Fresh-cut lettuce and parsnip showed significant 1.2 and 2.3 times increase, respectively, in TSP due to the combination effect of wounding and UV-B light exposure after 3 days of incubation. CONCLUSION: UV-B light exposure can be used as an additional processing step on selected specialty crops to enhance their soluble phenolic contents.