Autor(es):
Fernandes, Ângela 
; Carocho, Márcio ; Antonio, Amilcar L. ; Oliveira, M.B.P.P. ; Martins, Anabela ; Ferreira, Isabel C.F.R.
Data: 2013
Identificador Persistente: http://hdl.handle.net/10198/8656
Origem: Biblioteca Digital do IPB
Assunto(s): Wild mushroom; Macrolepiota procera; Processed samples; Antioxidant activity
Descrição
Mushrooms are very perishable food products and tend to lose quality immediately after harveStr. Drying is the
most common method for preserving mushrooms, freezing is becoming increasingly popular and food
irradiation has also been suggested by many researchers as a good conservation technique in order to
maintain and increase the food shelf life. In the present work, the effects of different processing technologies
(freezing, drying and gamma irradiation) on antioxidant activity of the wild mushroom Macrolepiota procera
were evaluated. Fruiting bodies were obtained in Trás-os-Montes, in the Northeast of Portugal, in November
2011. The irradiation was performed in experimental equipment with four 60Co sources at 0.6 kGy. The
samples were submitted to different processing technologies: freezing (at -20 ºC in a freezer), drying (at 30 ºC
in an oven) and gamma irradiation in fresh samples. Antioxidant activity was determined in the methanolic
extracts by in vitro assays measuring DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity,
reducing power, inhibition of β-carotene bleaching and inhibition of lipid peroxidation using thiobarbituric acid
reactive substances (TBARS) assay. Total phenolics were also determined by the Folin-Ciocalteu assay. Dried
samples gave the highest DPPH scavenging activity (50% at 2.7 mg/mL), β-carotene bleaching inhibition (50%
at 1.10 mg/mL) and the highest phenolic content (19.2 mg GAE/g methanolic extract). Frozen and irradiated
samples presented the highest reducing power (0.5 absorbance at 1.27 mg/mL) and TBARS formation
inhibition (50% at 0.78 mg/mL), respectively. The applied processing technologies affected favourably the
antioxidant potential of M. procera extracts, particularly dryness for DPPH scavenging activity and β-carotene
bleaching inhibition, freezing for reducing power and irradiation for TBARS formation inhibition.
