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United States Department of Agriculture

Agricultural Research Service

Title: Cultivation Conditions and Selenium Fertilization Alter the Phenolic Profile, Glucosinolate and Sulforaphane Content of Broccoli

Authors
item Robbins, Rebecca
item Keck, Anna-Sigrid - DFSHN, UN OF ILLINOIS
item Banuelos, Gary
item Finley, John

Submitted to: Journal of Medicinal Food
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 29, 2005
Publication Date: April 1, 2005
Citation: Robbins, R.J., Keck, A., Banuelos, G.S., Finley, J.W. 2005. Cultivation conditions and selenium fertilization alter the phenolic profile, glucosinolate and sulforaphane content of broccoli. Journal of Medicinal Food. 8:204-214.

Interpretive Summary: Broccoli is a food often consumed for its potential health-promoting properties. The health benefits of broccoli are partly associated with secondary plant compounds that have bioactivity in animals that consume broccoli; glucosinolates and phenolic acids are two of the most important classes of bioactive compounds. To learn how variety and growing conditions affect the production of these bioactive components, broccoli was grown in the greenhouse with and without selenium (Se) fertilization, and in the field under conventional or organic farming procedures and with or without water stress. HPLC-mass spec was used to identify 12 primary phenolic compounds. Organic farming and water stress decreased the overall production of phenolics. Selenium fertilization increased glucosinolates and sulforaphane in particular up to a point; above that Se fertilization decreased glucosinolate production. Organic farming and water stress also decreased glucosinolate production. These data show environmental and genetic variation in phenolics and glucosinolates in broccoli. They further show that selection for one bioactive component (selenium) may decrease the content of other bioactive components such as phenolics and glucosinolates

Technical Abstract: Broccoli is a food often consumed for its potential health-promoting properties. The health benefits of broccoli are partly associated with secondary plant compounds that have bioactivity in animals that consume broccoli; glucosinolates and phenolic acids are two of the most important classes of bioactive compounds. In an effort to determine how variety, stress and production conditions affect the production of these broccoli was grown in the greenhouse with and without selenium (Se) fertilization, and in the field under conventional or organic farming procedures and with or without water stress. HPLC-mass spec was used to separate and identify 12 primary phenolic compounds. Variety had a major effect, there was a preponderance of flavonoids in the Majestic variety, but hdroxy cinnamic acids were relatively more abundant in the Legacy variety. Organic farming and water stress decreased the overall production of phenolics. Selenium fertilization increased glucosinolates in general, and sulforaphane in particular up to a point; above that Se fertilization decreased glucosinolate production. Organic farming and water stress also decreased glucosinolate production. These data show environmental and genetic variation in phenolics and glucosinolates in broccoli, and show warn that not all broccoli may contain all health promoting bioactive components. They further show that selection for one bioactive component (selenium) may decrease the content of other bioactive components such as phenolics and glucosinolates.

Last Modified: 12/20/2014
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