Phytochemical characterization of Borago officinalis L. and Centaurea cyanus L. during flower development.

The present work details the nutritional and chemical compositions of borage and centaurea, at three flowering stages. Water was the main constituent, followed by total dietary fiber. Both flowers showed statistically different (p < 0.05) nutritional and chemical profiles, although in both, polyunsaturated fatty acids (PUFAs) (mainly linoleic and α-linolenic acids), free sugars (3.9-28.9% dw as fructose, glucose, and sucrose), tocopherols (with the major contribution of α-tocopherol from 1.24 to 2.75 mg/100 g dw), carotenoids (0.2-181.4 mg/100 g dw, mainly as lutein), and organic acids (6.1-14.4 g/100 g dw, mainly malic, succinic, and citric acids) were quantified. Concerning flowering, significant differences (p < 0.05) were found for some components, particularly carotenoids; however, no specific trend was observed in either of the two flower species. Thus, the present study shows that each flower species, as well as their flowering stages, may have different phytochemical and nutritional compositions.