The content of phenolic acids in the different duration fermented leaves of fireweed (Chamerion angustifolium (L.) Holub)

Abstract

The purpose of this study was to investigate and determine the effect of different duration of solid-phase fermentation on the change of phenolic acids in fireweed leaves. The leaves of fireweed (Chamerion angustifolium (L.) Holub), naturally growing in a biodynamic farm, were studied in 2017. The aw material was randomly collected from different places of the site in July, at the beginning of mass flowering. In the aboratory of the Institute of Agriculture and Food Sciences Agriculture Academy of Vytautas Magnus University crushed fireweed leaves were fermented under anaerobic conditions at 3°C in a closed dark room for 24 h or 48 h. The experiment was done in three replications. After the fermentation, the raw material was dried at 40°C. The amounts of phenolic acids were measured by high performance liquid chromatography (HPLC). The study data were statistically processed using the analysis of variance (ANOVA). The statistical significance of differences between the means was assessed by Fishers LSD test (p < 0.05). The results of the study indicate that after 24 h duration of solid-phase fermentations the mounts of benzoic and p-coumaric acids increased, but the quantities of gallic, chlorogenic and ellagic acids decreased. After 48 h the opposite results of solid-phase fermentation were observed, that is, the amount of gallic acid increased, while the quantities of chlorogenic, p-coumaric, ellagic and benzoic acids decreased.