ARS | Publication request: Identification of the phenolic components of collard greens, kale, and Chinese broccoli

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 15, 2009
Publication Date: July 24, 2009
Citation: Lin, L., Harnly, J.M. 2009. Identification of the phenolic components of collard greens, kale, and Chinese broccoli. Journal of Agricultural and Food Chemistry. 57(16):7401-7408.

Interpretive Summary: This paper presents the detailed identification of the flavonoids and hydroxycinnamic acid derivatives in three common brassica green leaf vegetables: collard greens, kale, and Chinese broccoli. It provides their phenolic component profiles and identifies 45 flavonoids and 13 other phenolics. Most of these phenolics are reported for the first time. This information will be helpful in establishing the potential benefits of these vegetables to human health.

Technical Abstract: An LC-MS profiling method was used to comprehensively study the phenolic components of collard greens, kale, and Chinese broccoli. This study led to the identification of 45 flavonoids and 13 hydroxycinnamic acid derivatives. All three plant materials contained kaempferol glycosides and acylgentiobiosides as major phenolics and quercetin glycosides as minor phenolics. In addition, each contained monocaffeoyl, mono-p-coumaroyl-, and monoferuloyl-quinic acids with the 3-position isomer as the dominant position. Isorhamnetin glycosides were detected in trace quantities in Chinese broccoli. Most of the phenolics identified in these vegetables are reported for the first time.