Terroir and vintage discrimination of Malbec wines based on phenolic composition across multiple sites in Mendoza, Argentina

This study evaluated the phenolic profiles of Malbec wines made from grapes of 23 parcels distributed in 12 geographical indications (GIs) from Mendoza, Argentina. Wines were elaborated under standardized winemaking conditions over three consecutive vintages (2016–2018). Data discriminated wines from different GIs and parcels, based on an integrative data analysis by chemometric tools. Vintage effect and specific phenolic compounds were associated with some GIs or parcels. As well, regional climate conditions allowed partial discrimination of the GIs (and also some parcels). A random forest analysis correctly identified 11 out of 23 individual parcels across the different vintages. The most notorious compounds associated with such classification were p-coumaric acid, delphinidin-3-O-glucoside, caffeic acid, quercetin and peonidin-3-O-glucoside. The presented research allows to individualize, through phenolic profiles, parcels with unique characteristics over years. This is the first report characterizing Malbec wines coming from several GIs (and individual parcels) in different vintages. These results are strongly related to terroir features of wines, contributing to a better communication to consumers and to position Argentinean wines.

Preferential incorporation oftrans,trans-conjugated linoleic acid isomers into the liver of suckling rats

The present study was designed to compare the conjugated linoleic acid (CLA) isomeric distribution pattern in the liver of suckling rats in relation to those in the milk and maternal diet. Silver-ion HPLC was used to separate individual CLA isomers. It was found that the isomeric distribution pattern in the milk was very similar to that in the maternal dietary fat. However, the CLA isomeric distribution patterns in the liver phospholipids (PL) and triacylglycerols were different from those in the diet and milk. In the liver PL, totalcis/transisomers accounted for 63·6–63·9 % of total CLA, which was in contrast to the values of 88·1–89·1 % in the milk and diet. In the liver PL, totaltrans/transisomers were 20·6–20·8 % of the total CLA isomers whereas they were only 2·6–3·7 % in the milk and diet. It is concluded thattrans/trans-CLA were preferentially incorporated into the liver whereas for the incorporation ofcis/trans-CLA there was partial discrimination.

The Vocalizations of Some Hybrid Treefrogs: Acoustic and Behavioral Analyses

The vocalizations of natural hybrids between various species of treefrogs (Hylidae) are compared with the vocalizations of the parental species : 1. In most respects, the calls of two males of H. avivoca X H. chrysoscelis and of six males of H. cinerea X H. gratiosa are intermediate. 2. The vocalizations of three males of H. femoralis X H. clarysoscelis tend to be similar to those of males of H. chrysoscelis. 3. The calls of each of the hybrids are composed, however, of some features which are intermediate, some which are similar to one of the parental species, and others which are unique to hybrid calls. Differentiation of the calls of males of H. avivoca, H. chrysoscelis, H. femoralis, and hybrids in this group is mainly in the temporal domain. Females of H. chrysoscelis and H. femoralis responded only to the calls of males of their own species in discrimination experiments where hybrid calls were alternative stimuli. The calls of males of H. cinerea, H. gratiosa and hybrids between these two differ primarily in their spectral composition : the two spectral peaks have different locations in each kind of call. In discrimination experiments, females of H. gratiosa responded only to conspecific calls when the calls of hybrids were equally accessible. Females of H. cinerea showed partial discrimination against the calls of hybrids. Females of both kinds often responded to the calls of hybrids when conspecific signals were unavailable. In general, the closer the spectrum of a natural call resembled that of conspecific calls, the more attractive was the acoustic signal.