Research Article

Estimation of the Content of Selected Active Substances in Primary and Secondary Herbal Brews by UV-VIS and GC-MS Spectroscopic Analyses

Figure 5

Concentration of polyphenols expressed in gallic acid equivalents (a) and flavonoids expressed in quercetin equivalents (b) in secondary herbal brews (after primary brewing) (mg L−1). Data are shown as mean ± SD. Different letters (a, b, c, etc.) show a significant difference with .
(a)
(b)