Abstract
The effects of elicitors on broccoli (Brassica oleracea L. var. Italica) and radish (Raphanus sativus L.) sprouts were evaluated. Seeds and then sprouts were soaked daily for 30 min over 6 days in water (control) or a mixture of FeEDTA and sodium silicate or sodium silicate alone. The contents of the flavonoids and phenolic acids (free, esters, and glycosides) were determined using HPLC-ESI-MS/MS. Phenolic compounds were released from the esters after acid hydrolysis and from the glycosides using alkaline hydrolysis. Quercetin, kaempferol, (‒)-epicatechin, naringenin, apigenin, and luteolin derivatives were found in broccoli and radish sprouts, while derivatives of iso-rhamnetin, orientin, and vitexin were not present at measurable levels. The flavonoid contents, especially derivatives of quercetin, were considerably higher in the broccoli sprouts than in the radish sprouts. The quantitatively major phenolic acid content in the sprouts of both species was found to be p-hydroxybenzoic acid. Its content in the radish sprouts was several times higher than in the broccoli sprouts. The total flavonoid content of broccoli sprouts was 507–734 µg/g DW, while that of the radish sprouts ranged from 155 µg/g DW to 211 µg/g DW. In contrast, total phenolic acids were higher in radish sprouts, ranging from 11,548 to 13,789 µg/g DW, while in broccoli sprouts, they ranged from 2652 to 4527 µg/g DW, respectively. These differences resulted radish sprouts having higher antioxidant activity compared to broccoli sprouts. The applied elicitors increased the content of the total phenolic acids and the antioxidant activity of radish and broccoli sprouts, while they decreased the level of the total flavonoids in broccoli sprouts.
Highlights
Seeds of the genus Brassicaceae are often used to produce sprouts and microgreens [1,2,3,4,5,6,7,8,9,10].Brassicaceae sprouts and microgreens are an excellent source of health-promoting compounds, including glucosinolates and isothiocyanates, polyphenols, minerals, and vitamins [11,12,13]
The radish and broccoli sprouts are mainly examined for their glucosinolate content, which can be further hydrolyzed into isothiocyanates [9,10]
Kaempferol, (-)-epicatechin, naringenin, apigenin, and luteolin derivatives were found in these sprouts, whereas iso-rhamnetin, orientin, and vitexin were not found at measurable levels
Summary
Seeds of the genus Brassicaceae are often used to produce sprouts and microgreens [1,2,3,4,5,6,7,8,9,10]. Brassicaceae sprouts and microgreens are an excellent source of health-promoting compounds, including glucosinolates and isothiocyanates, polyphenols, minerals, and vitamins [11,12,13]. Flavonoids and hydroxycinnamic acids are the most widespread group of polyphenolic compounds in plants [17,18,19,20]. The flavonoid biosynthetic pathway is part of a larger phenylpropanoid pathway that produces such secondary metabolites as phenolic acids, lignins, lignans, and stilbenes [17]. The beginning of the pathway is involved in the formation of the hydroxycinnamic acids by Biomolecules 2021, 11, 1190.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
