Bar Sorptive Extraction-gas Chromatography-mass Research Articles

Evaluation of the Effect of a Grape Seed Tannin Extract on Wine Ester Release and Perception Using In Vitro and In Vivo Instrumental and Sensory Approaches.

This study aimed to systematically evaluate the effect of a commercial grape seed tannin extract (GSE) fully characterized (53% monomers, 47% procyanidins) on wine ester release and perception using a global approach. The behavior of two esters (ethyl hexanoate, ethyl decanoate) was studied in a control wine or in the same wine supplemented with the GSE in preconsumption (in vitro headspace-stir bar sorptive extraction-gas chromatography mass spectrometry (HS-SBSE-GC/MS) and orthonasal perception) and consumption (intraoral-HS-SBSE-GC/MS and dynamic retronasal perception) conditions. For the compound ethyl hexanoate, no significant differences (p > 0.05) among wines were observed in the in vitro analyses while they were observed in the three in vivo experiments (p < 0.05). Thus, the wine supplemented with the GSE showed lower (35%) in vivo release and ortho (36%) and retronasal (16%) perception scores than the control wine. Overall, this suggests that components of the GSE could interact with this compound, directly and/or through complexes with oral components, affecting its release and conditioning its perception. However, perceptual interactions and effects of polyphenols on oral esterases cannot be discarded. On the contrary, the compound ethyl decanoate was not significantly affected by the addition of GSE. In conclusion, the addition of tannin extracts to wines can modulate aroma perception in a compound-dependent manner.

Principal Component Analysis of Hop-Derived Odorants Identified by Stir Bar Sorptive Extraction Method

Beers hopped with 79 varieties were brewed in small-scale fermenters, and 127 hop-derived compounds were picked up by comparing with the chromatogram of unhopped beer, after the analysis of the stir bar sorptive extraction gas chromatography-mass spectrometry method. The 127 hop-related flavor compounds were used to examine the interrelationship with the hop varieties by principal component analysis (PCA). Different varieties and amounts of hop pellets based on equal amounts of alpha-acids were added to the cooled wort. Addition of higher amounts of hops resulted in lower concentrations of apparent extracts of beer, suggesting the presence of dextrin-hydrolyzing enzymes in the hops. PCA largely established five directions. Direction I including Cascade, Amarillo, Citra, Simcoe, Mosaic, Wai-iti, and Hallertau Blanc varieties was linked to geraniol and citronellol, both known to contribute to citrus characteristics. Direction II including Bobek, Styrian Gold, and Moutueka varieties was associated with linalool and 6-methyl-5-hepten-2-one. Direction III including Hersbrucker and Saphir was linked to sesquiterpene alcohols. Direction IV was associated with hydrophobic monoterpenes, and direction V was linked to hydrophobic sesquiterpenes. Further study of these hop varieties and constituents can help advance our knowledge in using different hop varieties to achieve defined aroma and taste of beer.

Characterization and differentiation of high quality vinegars by stir bar sorptive extraction coupled to gas chromatography-mass spectrometry (SBSE–GC–MS)

A stir bar sorptive extraction gas chromatography–mass spectrometry (SBSE–GC–MS) method has been used for the characterization of the volatile composition of 26 high quality vinegars of three different protected geographical indications (traditional balsamic vinegar of Modena, balsamic vinegar of Modena, and Sherry vinegar). SBSE technique provided the identification of 113 volatile compounds, which belong to different chemical families (short-chain esters, acids, acetates and alcohols, phenols, lactones and benzenic and furanic compounds). 39 volatile compounds were never previously reported in wine vinegars. This characterization contributed to the differentiation of the 100% of the studied samples on the basis of raw material (two different types of wine, and cooked must), aging type (static and dynamic) and aging time (<5 years, between 5 and 25 years, and >25 years). Furanes and terpenes together with acids and alkanes were the most discriminant variables for raw material and aging time, respectively, whereas for aging type, these ones were acetates and esters.

Bound Volatile Precursors in Genotypes in the Pedigree of ‘Marion’ Blackberry (RubusSp.)

Glycosidically bound volatiles and precursors in genotypes representing the pedigree for 'Marion' blackberry were investigated over two growing seasons. The volatile precursors were isolated using a C18 solid-phase extraction column. After enzymatic hydrolysis, the released volatiles were analyzed using stir bar sorptive extraction gas chromatography-mass spectrometry (GC-MS) and direct microvial insert thermal desorption GC-MS. The most abundant volatile precursors in the genotypes were alcohols, followed by shikimic acid derivatives. High amounts of furanone glycosides were also detected, while norisoprenoids only existed in a small amount in blackberries. The volatile precursor composition in the genotypes in the 'Marion' pedigree was very similar to their free volatile distribution. 'Logan' and 'Olallie' predominantly had bound norisoprenoids. Wild 'Himalaya' predominated with terpene alcohol and furaneol glycosides, whereas 'Santiam' and 'Chehalem' contained a high level of terpene alcohol glycosides. A similar inheritance pattern was also observed for some volatile precursors in the genotypes in the 'Marion' pedigree. A high content of linalool, hydroxylinalool, and alpha-ionol glycosides in 'Olallie' and a low content in 'Chehalem' resulted in a moderate level in their offspring 'Marion', while a low content of (E)-linalool oxide precursor in 'Olallie' and a high content in 'Chehalem' also resulted in a moderate level in 'Marion'. However, the concentration of furaneol glycosides in 'Marion' exceeded that of its two parents.