Effect of Wood Aging on Wine Mineral Composition and 87Sr/86Sr Isotopic Ratio.

The evolution of mineral composition and wine strontium isotopic ratio 87Sr/86Sr (Sr IR) during wood aging were investigated. A red wine was aged in stainless steel tanks with French oak staves (Quercus sessiliflora Salisb.), with three industrial scale replicates. Sampling was carried out after 30, 60, and 90 days of aging, and the wines were evaluated in terms of general analysis, phenolic composition, total polysaccharides, multielement composition, and Sr IR. Li, Be, Mg, Al, Sc, Ti, V, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Rb, Sr, Y, Zr, Mo, Sb, Cs, Ba, Pr, Nd, Sm, Eu, Dy, Ho, Er, Yb, Lu, Tl, and Pb elements and 87Sr/86Sr were determined by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) and Na, K, Ca, and Fe by flame atomic absorption spectrometry (FAAS). Two-way ANOVA was applied to assess wood aging and time effect on Sr IR and mineral composition. Wood aging resulted in significantly higher concentrations of Mg, V, Co, Ni, and Sr. At the end of the aging period, wine exhibited statistically identical Sr IR compared to control. Study suggests that wood aging does not affect 87Sr/86Sr, not precluding the use of this parameter for wine traceability purposes.

HPLC method for the quantification of phenolic acids, phenolic aldehydes, coumarins and furanic derivatives in different kinds of toasted wood used for the ageing of brandies.

A simple, rapid and accurate HPLC method allowing the quantification of phenolic acids, phenolic aldehydes, coumarins and furanic derivatives in different kinds of toasted wood used in the ageing of wine brandies was developed and validated. The validated method presents good linearity, low limits of detection and quantification (LOD ranging between 0.03 µg L-1 for umbelliferone and 1.10 mg L-1 for ellagic acid, and LOQ ranging between 0.09 µg L-1 for umbelliferone and 3.66 mg L-1 for ellagic acid), high sensitivity, good repeatability (relative standard deviations ranging between 0.25% and 2.21%) and suitable recovery (mean values higher than 90% for all the concentrations added and compounds, except for vanillic acid). It can therefore be of a great interest for research studies and for quality control in routine analyses requested by the brandy producers, coopers and technicians, as a tool to know the low molecular weight composition of the toasted wood. The analysis of four different kinds of toasted wood (chestnut, Portuguese oak, Limousin oak and American oak) demonstrates the applicability of the method on the characterization and differentiation of the wood botanical species.

Photoactive extracts from Thevetia peruviana with antifungal properties against Cladosporium cucumerinum.

Seeds of Thevetia peruviana were screened for their antifungal photoactivity. Extracts obtained either with n-hexane or dichloromethane were fractionated by column chromatography and further analysed by thin-layer chromatography. All seed extracts and fractions were tested for inhibition of the fungus Cladosporium cucumerinum for the evaluation of photoactive inhibitory effects. Antifungal light-dependent activity was observed for some of the fractions and both crude extracts. The most photoactive fraction was analysed by capillary gas chromatography with mass spectrometry in order to identify its constituents. Two major groups of compounds were identified, terpenes and fatty acids and derivatives. Pulegone, linoleic acid and palmitic acid were the major compounds. Terpenes seem to be the major substances with antifungal photoactivity.