Multivariate analysis for the classification and differentiation of Madeira wines according to main grape varieties

Abstract

In order to differentiate and characterize Madeira wines according to main grape varieties, the volatile composition (higher alcohols, fatty acids, ethyl esters and carbonyl compounds) was determined for 36 monovarietal Madeira wine samples elaborated from Boal, Malvazia, Sercial and Verdelho white grape varieties. The study was carried out by headspace solid-phase microextraction technique (HS-SPME), in dynamic mode, coupled with gas chromatography-mass spectrometry (GC-MS). Corrected peak area data for 42 analytes from the above mentioned chemical groups was used for statistical purposes. Principal component analysis (PCA) was applied in order to determine the main sources of variability present in the data sets and to establish the relation between samples (objects) and volatile compounds (variables). The data obtained by GC-MS shows that the most important contributions to the differentiation of Boal wines are benzyl alcohol and (E)-hex-3-en-1-ol. Ethyl octadecanoate, (Z)-hex-3-en-1-ol and benzoic acid are the major contributions in Malvazia wines and 2-methylpropan-1-ol is associated to Sercial wines. Verdelho wines are most correlated with 5-(ethoxymethyl)-furfural, nonanone and cis-9-ethyldecenoate. A 96.4% of prediction ability was obtained by the application of stepwise linear discriminant analysis (SLDA) using the 19 variables that maximise the variance of the initial data set.

Comparative study of the whisky aroma profile based on headspace solid phase microextraction using different fibre coatings

“…The methodology developed by Câmara et al [21,29] for the volatile compounds extraction using HS-SPME was used with minor modifications.…”

A fast method using a new hydrophilic–lipophilic balanced sorbent in combination with ultra-high performance liquid chromatography for quantification of significant bioactive metabolites in wines

“…These compounds have a strong influence on the quality and character of the wine, and therefore are important not only for their characterization and differentiation, but also for fraud detection [1][2][3][4][5][6]. In recent years considerable attention is being paid to natural substances with antioxidant activity, which play a crucial role in the prevention of cardiovascular, neurodegenerative and cancer diseases acting through different mechanisms, namely direct trapping of reactive oxygen species (ROS) and reactive nitrogen species (RNS, i.e.…”

“…Grapes and grape-derived products such as red wine are an abundant source of antioxidants (phenolic compounds) and represent an important dietary component [1,2]. Their nature and content can vary significantly according to different intrinsic and extrinsic factors such as plant genetics and cultivar, soil composition and growing conditions, maturity state and post-harvest conditions, among others [5,6]. Phenolic compounds, mainly polyphenols, are responsible for some of the organoleptic characteristics of the fruits, food and drinks [7], and act as potent antioxidants, reinforcing antioxidant system against ROS and RNS.…”

Dotazione in composti aromatici della varietà Italia in relazione all'incisione anulare e alla somministrazione di acido gibberellico

“…Il ruolo dell'Italia nel contesto mondiale di produzione di uva da tavolaè significativo essendo il quinto produttore al mondo. Nella produzione di uva da tavola gli aspetti carpometrici legati alla dimensione della bacca e del grappolo richiedono una serie di interventi in vigneto in grado di massimizzare tali parametri [1][2][3][4][5][6] Nella ricerca sono state poste a confronto diverse tecniche quali l'incisione anulare del tronco, l'incisione anulare dei capi a frutto, l'irrorazione di acido gibberellico sui grappoli (due interventi a 40 ppm), valutando alla raccolta sia le dimensioni della bacca che ladotazione dei terpeni, responsabili del caratteristico aroma della varietà Italia [7][8][9][10][11]. L'incisione anulare, cheè stata effettuata in post-allegagione, rientra nella viticoltura da tavola tra le tecniche di potatura verde e consiste nell'incidere e rimuovere un anello di corteccia dal tronco o dal capo a frutto, determinando un interruzione del movimento del flusso floematico [12][13][14][15] I risultati della tecnica sono legati all'epoca di esecuzione, con incrementi di allegagione nel caso di interventi in fioritura, mentre in fase di invaiatura sono segnalati incrementi dell'accumulo glucidico con evidente anticipo dell'epoca di raccolta [3] Interventi di incisione e decorticazione anulare hanno determinato l'aumento della disponibilità di carboidrati per i grappoli e miglioramento dello stato idrico delle viti [14].…”