Stir Bar Sorptive Extraction Combined with GC-MS Analysis and Chemometric Methods for the Classification of South African Wines According to the Volatile Composition

Abstract

A simple method for the analysis of major wine volatiles and semivolatiles by stir bar sorptive extraction in combination with thermal desorption and gas chromatography-mass spectrometry (SBSE-TD-GC-MS) was developed. Significant experimental parameters such as extraction time, temperature, salt addition, pH, and thermal desorption parameters were optimized to provide a sensitive and robust analytical method. The method provided good repeatability (%RSD < 10%) for 38 major wine volatile compounds, including alcohols, acids, esters, phenols, aldehydes, ketones, and lactones. Quantitative data for 62 South African red and white wines were used to study the suitability of major volatile data for the differentiation of wine samples according to grape variety or cultivar. Principal component analysis (PCA) and cluster analysis (CA) showed that most of the variation in volatile composition between wine samples could be ascribed to differences in wine age, wood contact, and fermentation practices. Despite the contribution of these factors, discriminant analysis (DA) was successfully applied to the classification of red and white wine samples according to cultivar.

Classification of Chinese Rice Wine According to Geographic Origin and Wine Age Based on Chemometric Methods and SBSE-TD-GC-MS Analysis of Volatile Compounds

“…The most common in wines are ethyl esters (Tredoux et al, 2008). A total of 30 esters were detected in the 27 samples.…”

“…Stir bar sorptive extraction (SBSE) has recently been introduced as another sample preparation method. Because of the increased quantity of stationary phase utilized, SBSE offers increased sensitivity compared with SPME (Tredoux et al, 2008;Maggi et al, 2008;Hayasaka et al, 2003). This new method has been used for identifying the volatile compounds in Madeira wine (Alves et al, 2005) and "Terras Madeirenses" table wines (Perestrelo et al, 2009).…”

“…The volatile compounds are centrally important to ensuring the identity of wine (Pereira et al, 2010), as their contents depend on the brewing technology, geographic origin and aging process (Tredoux et al, 2008). Much attention has been paid to the volatile profiles of wine, including research on the classification of liqueur wines (Pereira et al, 2010), the discrimination of white wine (Hernanz et al, 2009), the characterization of Vino (Gil et al, 2006) and the classification of red wine (Zhang et al, 2010; Alejandro Calleja and Falqué, 2005).…”

“…L to mg/L (Tredoux et al, 2008). The solid-phase microextraction (SPME) method has been widely used in flavor analysis of wine (Ryan et al, 2005;Rodrigues et al, 2008;De León-Rodríguez et al, 2006).…”

“…The volatile compounds are centrally important to ensuring the identity of wine (Pereira et al, 2010), as their contents depend on the brewing technology, geographic origin and aging process (Tredoux et al, 2008). Much attention has been paid to the volatile profiles of wine, including research on the classification of liqueur wines (Pereira et al, 2010), the discrimination of white wine (Hernanz et al, 2009), the characterization of Vino (Gil et al, 2006) and the classification of red wine (Zhang et al, 2010; Alejandro Calleja and Falqué, 2005).Sample preparation is vitally important in gas chromatographymass spectrometry (GC-MS) analysis, as these levels range from μg/L to mg/L (Tredoux et al, 2008). The solid-phase microextraction (SPME) method has been widely used in flavor analysis of wine (Ryan et al, 2005;Rodrigues et al, 2008;De León-Rodríguez et al, 2006).…”