Antioxidant content of edible sprouts: effects of environmental shocks

BACKGROUND: Edible sprouts are thought to be rich in health-promoting phytochemicals that are known to prevent a number of chronic and degenerative diseases. In mature plants, environmental shocks have been used to enhance health-promoting phytochemicals. The primary objective of this study was to use environmental shocks involving high light and chilling in sprouts of alfalfa, broccoli and radish to improve their phenolic composition. RESULTS: Young sprouts had high total phenolic content and correspondingly high antioxidant capacity, both of which declined sharply with plant age. Exposure of sprouts to high light or chilling resulted in higher total phenolic content and antioxidant capacity compared with untreated controls. During recovery following shock treatments, high light produced a stronger response in increasing the levels of individual phenolic compounds. Alfalfa sprouts subjected to high light and chilling accumulated about 2.0 and 1.5 times significantly higher concentration of ferulic acid respectively, while high light induced 83% more sinapic acid in broccoli sprouts compared with untreated controls. Myricetin, while not detected in 5-day-old control or chilli ng-treated radish sprouts, accumulated in response to high light. Environmental shocks did not adversely affect the dry biomass accumulation. CONCLUSION: Environmental shocks involving high light and chilling enhanced the antioxidant phenolic content in sprouts of alfalfa, broccoli and radish, suggesting that this approach can be successfully used to enhance the health-promoting qualities of these sprouts. (C) 2009 Society of Chemical Industry