Antioxidant and bioactive compounds of two wild edible mushrooms from Northeast of Portugal: Boletus poliporus and Boletus regius
Conference Paper
Overview
Overview
abstract
FCT and COMPETE/QREN/EU: project PTOC/AGR-ALI/110062/2009, PEst-PTDC/AGRALI/110062/2009 CIMO strategic project and L B. grant (BPD/4609/2008)
Free radicals are produced in the normal natural metabolism of aerobic cells, mostly in the form of
reactive oxygen species (ROS). Maintenance of equilibrium between free radicals production and
antioxidant defenses is an essential condition for normal organism functioning [1 ,2]. Although
almost all organisms are equipped with antioxidant defense, the antioxidant supplements, or
natural products containing bioactive compounds, may be used to help reduce oxidative damage
to the human body (3]. Indeed, natural matrices with antioxidant activity, in particular mushrooms,
are used to aid the endogenous protective system, increasing interest in the antioxidative role of
functional foods or nutraceutical products (2]. The present study describes the antioxidant
properties and bioactive compounds of wild edible mushrooms (Boletus porosporus and Boletus
regius) collected in Northeast of Portugal (Bragança). The antioxidant properties were assessed
through the evaluation of the reducing power, radical scavenging activity and lipid peroxidation
inhibition of the samples. The individual profiles of organic acids and phenolic compounds were
obtained by high performance liquid chromatography coupled to photodiode array detector
(HPLC-POA) and the tocopherols were characterized by HPLC-fluorescence.The Boletus regius
sample revealed the best results in all the antioxidant activity assays, with the highest reducing
power, highest scavenging activity and highest lipid peroxidation inhibition. Phenolic acids and a
related compound (cinnamic acid) were found in both studied species and B. regius revealed the
highest content in total phenolic compounds (23.49 mg/1 00 g dw), mainly due to the presence of
two possible flavonoids. The highest levels of total tocophero ls were found in B. regius (763.80
j.Jg/1 00 g dw). The highest content in quinic and oxalic acids were found in B. porosporus(1.93
and 0.34 g/1 00 g dw, respectively), while B. regius revealed the highest level of citric acid (3.32
g/1 00 g dw).The results suggest that species of wild mushrooms from Northeast Portugal are a
potential source of antioxidants to be explored.
