Simple distinction of grapevine (Vitis vinifera L.) genotypes by direct ATR-FTIR.

The identification of grapevine (Vitis vinifera L.) genotypes is conventionally a laborious activity that must be carried out by specialized staff. In this work a novel and simple method for differentiation of grapevine genotypes is presented. Direct measurements of leaves by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) combined with chemometric methods were used for classification of six genotypes (five varieties and a pair of clones), viz. Cinsault, Gewurztraminer (clone 643), Moscatel de Alejandría, País, Pinot Noir (French clone 777), Pinot Noir (local clone 'Valdivieso'). These were successfully classified and identified through supervised pattern recognition methods such as soft independent modeling of class analogy (SIMCA) and partial least square discriminant analysis (PLS-DA). The error rate for spectra classification of test sets by both models was 0.08. The results demonstrate the advantages of using ATR-FTIR as a rapid and non-destructive tool that achieves accurate grapevine genotype differentiation.

Size exclusion chromatography - Inductively coupled plasma - Mass spectrometry for determining metal-low molecular weight compound complexes in natural wines.

Size exclusion chromatography (SEC) hyphenated to inductively coupled plasma - mass spectrometry (ICP-MS), as a specific detector for metals, has been used for monitoring and determining metal-low molecular weight organic compound (LMWC) complexes in natural wines. SEC with UV detection (wavelength of 205 nm) was used for monitoring organic compounds eluted from the chromatographic column. SEC-UV has revealed the presence of low molecular weight compounds (commonly three fractions of molecular weights ranging from 230 to 1579 Da).' Further experiments using ICP-MS as a detector showed that elements such as B, Cu, Li, Mn, Ni, Ti, and Zn are bound to compounds of molecular weights within the 338-1579 Da range. Total metal concentrations, as well as metal concentrations in SEC fractions were also assessed in several monovarietal red (five varieties) and monovarietal white (three varieties) wines.

In vitro human bioavailability of major, trace and ultra-trace elements in Chilean 'natural' wines from Itata Valley.

In vitro human bioavailability of elements in 'natural' wines from Chile's Itata Valley has been assessed using an in vitro dialyzability approach. The red wines (fifteen samples) were of the Cinsault, Cabernet sauvignon, Carmènére, Malbec, and Pinot noir varieties. All white wines (three samples) were of the Muscat of Alexandria variety. Inductively coupled plasma-mass spectrometry was used for determination. Elements such as Ag, As, Be, Cd, Cr, Hg, Mo, Ni, Pb, Sb, Se, Sn, Ti, Tl, and V were not found to be bioavailable (concentrations lower than the limit of detection in the dialysates). Elements such as Al, Co, and Fe showed low bioavailability ratios (lower than 20%), whereas B, K, Li, Mg, and Mn were found to be of moderate bioavailability (bioavailability ratios within the 20-79% range for most wine samples). Ca, Cu, and Sr bioavailability was moderate (higher than 20%) in some wines, but most of the samples showed Ca, Cu, and Sr bioavailabilty ratios lower than 20%. No differences were found regarding bioavailability ratios among red and white wines, or among the grape varieties.