Propriedades antioxidantes e perfil dos compostos fenólicos de cogumelos

Abstract

Mushrooms have been part of the normal human diet for thousands of years and, in recent times, the amounts consumed have risen greatly, involving a large number of species. Besides the nutritional properties, mushrooms have been demonstrated to possess healthy properties. In this study, three varieties of mushrooms were evaluated: Champignon, Shimeji and Shiitaki. Absolute methanol was used to obtain the crude extracts of the mushrooms (1:20, w/v). The total phenolic compounds of the mushrooms were determined using the Folin-Ciocalteau method. Flavonoids were estimated using the colorimetric method with aluminium chloride and the pH differential assay was used to quantify the total anthocyanins in the samples.1,1- Diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activity and coupled autoxidation of β- carotene and linoleic acid assays were used to obtain the EC50 values of the samples. Reverse-phase high-performance liquid chromatography with diode-array detection (RP-HPLCDAD-UV/Vis) was used for the separation and identification of phenolic compounds in the mushrooms extracts. Among the three mushrooms studied, champignon presented the highest concentration of total phenolic compounds (6.40 ± 0.22 mg GAE/g dry basis) and flavonoids (2.36 ± 0.19 mg CE/g dry basis). Anthocyanins were only detected in the sample of Shimeji (2.54 ± 0.13 mg/100g dry basis). The mushroom with the highest antioxidant potential was shiitaki (EC50 values of 16.83 ± 0.31 μg/mL and 26.46 ± 0.37 μg/mL in the DPPH and in the β-carotene/ linoleic acid assays, respectively). Different phenolic compounds were identified by HPLC analysis in each sample. The highest concentration was found in Champignon, being rutin significantly present.