A note on the effectiveness of selenium supplementation of Irish-grown Allium crops.

Abstract

Onions and other Allium crops contain high levels of dietary phenolics and, unlike many other crops, accumulate the beneficial mineral selenium. Selenium-enhanced Allium crops are of interest both from a public good perspective and as a market positioning strategy for growers. Field trials were carried out to i) identify onion and scallion varieties that contain high levels of health-promoting phenolic and flavonoid compounds as potential targets for selenium supplementation and ii) investigate selenium supplementation in the widely-grown commercial onion variety ‘Hyskin’ at different application rates of nitrogen fertilizer. Levels of selenium in onion bulbs were significantly increased from 0.5–5.9 μg/g dry weight (DW) to 40.6–70.0 μg/g DW.