Florets of Sunflower (Helianthus annuus L.): Potential New Sources of Dietary Fiber and Phenolic Acids

Qiang Liang, Jun Cui, Hang Li, Jia Liu, and Guohua Zhao

Abstract

Ray florets (Rf) and disc florets (Df) are agricultural byproducts of sunflower seeds. Their nutrition-related compounds were determined. The dietary fiber contents in Rf and Df were 42.90 mg/100 g and 58.97 mg/100 g. In both florets, palmitic, linoleic, and linolenic acids were identified as the three most abundant fatty acids, and the saturated ones constitute approximately two-thirds (w/w) of the total fatty acids. Lysine was the limiting amino acid in both florets by World Health Organization standards. Sixteen phenolic compounds, nine free and eight bound, mainly depsides, were identified in florets by RP-HPLC-DAD/ESI-TOF-MS. The free and bound phenolic compounds in Df were higher than in Rf. 1,5-di-O-caffeoylquinic acid was the predominant free phenolic compound in both florets. The present study revealed that the florets of sunflower are rich sources of dietary fiber, Fe, and phenols.

Isoquercitrin, chlorogenic acid, ferulic acid, caffeic acid, and p-coumaric acid (>98.0%)
were commercially purchased from Chengdu Biopurify Phytochemicals (Chengdu, China).