Desert truffle, Tirmania pinoyi (Maire) Malençon from Libya was chemically characterized in nutritional value, primary and secondary metabolites. Antioxidant (scavenging activity, reducing power and inhibition of lipid peroxidation) and antibacterial activity of its methanolic extract alone and in combination with potassium metabisulfite (E224) were evaluated under in vitro conditions. Furthermore, the effect of the extract on the control of Staphylococcus aureus was examined in a contaminated soup under in situ conditions. T. pinoyi was showed to be rich in carbohydrates (82.60 g/100 g dw) and proteins (8.06 g/100 g dw), being identified four free sugars (rhamnose, fructose, trehalose and mannitol) and three tocopherol isoforms (β-, δ- and γ-tocopherols). Oleic (32.29%), linoleic (29.72%) and palmitic (27.97%) acids were the main fatty acids. p-Hydroxybenzoic (300.65 µg/100 g dw) and cinnamic (8.30 µg/100 g dw) acids were quantified, as also four organic acids: quinic (0.83 g/100 g dw), malic (0.35 g/100 g dw), fumaric (0.05 g/100 g dw) and citric (1.26 g/100 g dw) acids. The methanolic extract of the mushroom showed in vitro antioxidant and antimicrobial activities. Sterilized distillated water containing 0.02% Tween 80 proved to be the most convenient solvent for in situ antimicrobial activity; the extract successfully inhibited the growth of S. aureus in chicken soup in a dose dependent manner.
Foundation for Science and Technology (FCT, Portugal) and COMPETE/QREN/EU for financial support to this work (bilateral cooperation action Portugal/Serbia 2011, research project PTDC/AGR-ALI/110062/2009 and BPD/4609/2008 to L. Barros) and to CIMO (strategic project PEst-OE/AGR/UI0690/2011). The authors also thank to Serbian Ministry of Education and Science for financial support (grant number 173032).
