Chemical and Sensory Characterization of Cabernet Sauvignon Wines from the Chinese Loess Plateau Region

Flavoromic analysis of wines using gas chromatography, mass spectrometry and sensory techniques

Various sensory perceptions drive the quality and typicality of wines, with the volatile profile playing a fundamental role in the characteristics of odor, aroma and consequently flavor, which combines the smell (odor and aroma), taste, and trigeminal sensations. Efforts have been made in both the field of instrumental and sensory analysis to understand the relationship of volatile compounds with sensory attributes in omics approaches. Gas chromatography (monodimensional and two-dimensional (heartcutting and comprehensive)) associated with mass spectrometry (GC/MS, GC-GC/MS and GCxGC/MS) and chemometric tools have contributed to foodomics analyses, specifically those linked to metabolomics/volatilomics. These tools, along with the elucidation of sensory properties (sensomics), lead to advanced results in the field of flavoromics. They also help to define the best practices in both vineyard management and winemaking that enable the production of high-quality wines. The objective of this review is to report the challenges of determining the volatile profile of wines, pointing out the ways that can be followed in successful identification and quantification of volatile compounds. The state of the art of sensory evaluation methods is also addressed, providing information that helps in choosing the most appropriate sensory method to be conducted with chromatographic analysis to achieve more in-depth results in the field of flavoromics.

Authentication of selected white wines by geographical origin using ICP spectrometric and chemometric analysis

An important aspect of assessing the authenticity of wines is its geographical origin. The aim of the work is to authenticate by geographical origin according to the data of the ICP-spectrometric and chemometric analysis of elemental "images" of wines produced from white grape varieties Chardonnay, Riesling and Muscat grown in four regions of the Krasnodar Territory, Russia. The difference in the contents of Al, Ba, Ca and Rb in wines was found depending on the variety, and Al, Ba, Rb, Fe, Li, Sr - depending on the region of grape growth. Different models of the experimental data processing were used for attribution of the produced varieties of wine to the area of the grape's growth. The criterion for the quality of the constructed models was the accuracy of the attribution of a wine variety to the area of the grape's growth (%). Analysis of the elemental analysis data of 153 wine samples showed that in terms of attribution accuracy, automated neural networks (100 %) are preferred among machine learning methods, followed by support vector machines (98.69 %) and general discriminant analysis (94.77 %). The applied mathematical models enabled the revealing of the cluster structure of the analyzed wine varieties and their attribution to the area of a grape growth with high accuracy. Sr, Li and Fe concentrations in wines were found as the dominating predictors in the constructed models for definition of the geographical origin of wines. The combination of ICP-spectrometric analysis data with the capabilities of statistical modeling of machine learning methods focused on large-dimensional data made it possible to successfully solve small-dimensional problems of the definition of the geographical origin of wines by their elemental composition and variety.

Comparative Analysis of the Evolution of Green Leaf Volatiles and Aroma in Six Vitis vinifera L. Cultivars during Berry Maturation in the Chinese Loess Plateau Region

Green leaf volatiles (GLVs) are important in giving grape a fresh and green aroma. But the changes in GLVs during the phenological development of grapevines are not well known. This study analyzed the GLVs and transcription levels of associated biosynthetic genes in six grape species from the Loess Plateau region at five stages of maturation. Thirteen GLVs were detected, showing unique patterns for each grape type at various growth phases. The primary components in six grapes were (E)-2-hexenal, (E)-2-hexen-1-ol, and hexanal. With the exception of Cabernet Franc in 2019, the overall GLV contents of the six types generally increased during growth and development, peaking or stabilizing at harvest. And Sauvignon Blanc, Cabernet Gernischt, and Cabernet Sauvignon exhibited higher total contents among the varieties. PLS-DA analysis revealed 3-hexenal's high VIP scores across two years, underscoring its critical role in grape variety classification. Correlation analysis revealed a strong positive correlation between the levels of hexanal, 1-hexanol, (E)-2-hexen-1-ol, (Z)-3-hexenyl acetate, nonanal, and (E, E)-2,6-nonadienal and the expression of VvHPL and VvAAT genes in the LOX-HPL pathway. Specifically, VvHPL emerges as a potential candidate gene responsible for species-specific differences in GLV compounds. Comprehending the changing patterns in the biosynthesis and accumulation of GLVs offers viticulturists and enologists the opportunity to devise targeted strategies for improving the aromatic profile of grapes and wines.

Characterization of wine volatile compounds from different regions and varieties by HS-SPME/GC-MS coupled with chemometrics

HS-SPME/GC-MS and aroma descriptive analysis were used to gain insights into the volatile and sensory details of 99 red wine samples collected from four varieties in five regions. The general volatile fingerprints of Cabernet Sauvignon and Merlot wine samples in Xinjiang and Ningxia regions were similar, even though chemometric models could not discriminate between them. The main drivers of the diversity were secondary metabolites of grape such as terpenes, benzene-derivatives, and ketones. Fermentation-derivatives (esters and alcohols) were also responsible for region and variety-related differences in wines. Analysis of volatile compounds also showed that the primary factor accounting for diversity in wines in this study was region rather than variety. These results highlight the sensory attributes and volatiles of different regions and varieties, and provide a quantitative basis for screening for differential metabolites and potential markers in wines.

Influence of elongation and desaturation on chemosensory properties in acrylates and their corresponding 1-alken-3-ones

Acrylates as well as 1-alken-3-ones are both known to be odour active substances but are generally identified in different materials. Nonetheless, butyl acrylate and 1-octen-3-one were both found to elicit a similar mushroom-like odour in previous studies. This led to the question of whether acrylates and enones with the same overall chain length generally elicited similar odours and whether they had similar odour thresholds. Overall, most of the investigated substances showed a mushroom-like, geranium-like or fruity odour. In contrast, short chained substances elicited garlic-like, lighter gas-like or glue-like, odour qualities, suggesting a correlation between the odour quality and the overall chain length. The results showed that only between the analogue structures butyl acrylate and 1-octen-3-one as well as hexyl acrylate and 1-decen-3-one could similar odour qualities be observed. All investigated substances showed low odour threshold values in air between 0.0032 ng/l_air (1-hexen-3-one) and 55 ng/l_air (1-dodecen-3-one). Overall, 1-alken-3-ones revealed a higher dependency on the chain length when compared to their respective acrylates. The introduction of a second terminal double bond led to a decrease of OT values in case of the acrylates and to an increase in case of the ketones that neither contained a second terminal double bond nor a double bond located close to the carbonyl group. Despite their structural similarities, the results suggest that both substance classes are perceived in a different manner and are therefore likely to be recognized by different types of receptors or are related to different activation patterns in multi-receptor stimulation processes.

Effects of ergothioneine-enriched mushroom extract on oxidative stability, volatile compounds and sensory quality of emulsified sausage

OBJECTIVE

The aim of this work was to assess the effect of ergothioneine (ESH)-enriched mushroom extract on oxidative stability, volatile compounds, and sensory quality of emulsified sausage.

METHODS

The ESH content was determined by high performance liquid chromatography. The antioxidant activity of Flammulina velutipes (F. velutipes) extract was determined through radical-scavenging activity of 1,1 diphenyl-2-picryl-hydrazyl, 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals. Four different groups of emulsified sausage were manufactured: control, no antioxidants; BHA, 0.01% butylated hydroxyanisole; EEME, 0.8% ESH-enriched mushroom (F. velutipes) extract; AE, 0.012% authentic ESH, after storage for 14 days (at 4°C), the quality of sausage including oxidative stability (2-thiobarbituric acid reactive substances and protein carbonyls content), volatile compounds and sensory quality were studied.

RESULTS

It was demonstrated that adding ESH-enriched F. velutipes extract to sausage could effectively prevent lipid and protein oxidation, and its efficacy was equivalent with 0.01% BHA. During meat processing, the ESH mainly contributed to the antioxidative activity of F. velutipes extract. The flavor and sensory attributes of emulsified sausage were improved through adding ESH-enriched F. velutipes extract.

CONCLUSION

Accordingly, the extract of F. velutipes contained high-level of ESH and could be a good antioxidant candidate for processed meat production.

Comparison of Aroma Compounds in Cabernet Sauvignon Red Wines from Five Growing Regions in Xinjiang in China

A total of 55 volatiles including esters (29, 52.73%), alcohols (10, 18.18%), acids (3, 5.45%), alkanes (8, 14.55%), and other components (5, 9.09%) were evaluated in five regions. Total concentrations were 0.05–222.23 mg/L, which covered the highest esters (222.23 mg/L) and alcohols (120.65 mg/L) in Turpan, acid (0.53 mg/L) in Shihezi, and alkanes (1.43 mg/L) and others (3.10 mg/L) in the Ili River valley. It proved that numbers and concentrations of volatile compounds, including common ingredients of variety, were closely linked to ecological characteristics of a region. Esters and alcohols were the major ingredients in Xinjiang Cabernet Sauvignon wine. Additionally, appellation could affect performance of concentration, ODE, and OTH, especially for the same flavor substance by fermentation, aging, and even formation and transformation in wines. Therefore, three conditions for formation of flavors were successively appellations, metabolism and fermentation, and and appropriate altering according to technology and their decisive role in wine quality. Each volatile compound had its own flavor, the combination of which complicated the flavor. The unique materials in the region were grounded for the development of products with corresponding flavors by producing substrate for fermentation. When choosing a wine you enjoy, the right appellation should be considered first.

Aroma Profile and Chemical Composition of Reverse Osmosis and Nanofiltration Concentrates of Red Wine Cabernet Sauvignon

Wine aroma represents one of the main properties that determines the consumer acceptance of the wine. It is different for each wine variety and depends on a large number of various chemical compounds. The aim of this study was to prepare red wine concentrates with enriched aroma compounds and chemical composition. For that purpose, Cabernet Sauvignon red wine variety was concentrated by reverse osmosis (RO) and nanofiltration (NF) processes under different operating conditions. Different pressures (2.5, 3.5, 4.5 and 5.5 MPa) and temperature regimes (with and without cooling) were applied on Alfa Laval LabUnit M20 equipped with six composite polyamide RO98pHt M20 or NF M20 membranes. Higher pressure increased the retention of sugars, SO₂, total and volatile acids and ethanol, but the temperature increment had opposite effect. Both membranes were permeable for water, ethanol, acetic acid, 4-ethylphenol and 4-ethylguaiacol and their concentration decreased after wine filtration. RO98pHt membranes retained higher concentrations of total aroma compounds than NF membranes, but both processes, reverse osmosis and nanofiltration, resulted in retentates with different aroma profiles comparing to the initial wine. The retention of individual compounds depended on several factors (chemical structure, stability, polarity, applied processing parameters, etc.).

Role of gas chromatography and olfactometry to understand the wine aroma: Achievements denoted by multidimensional analysis

The human nose has been used as a detector in gas chromatography analysis to evaluate odoriferous compounds related to aroma and quality of wine. Several olfactometric techniques are available to access the description, intensity, and/or duration of the odor of each compound. Olfactometry can be associated with one-dimensional gas chromatography or multidimensional gas chromatography, including heart-cut gas chromatography and comprehensive two-dimensional gas chromatography. Multidimensional gas chromatography may help to resolve coeluted compounds and detect important trace components for the aroma. The identification of odor-active compounds may help to differentiate wines according to terroir, grapes cultivars used in winemaking or types of aging, understand the role of fungal infection of grapes for wine quality, find the best management practices in vineyard and vinification to obtain the greatest quality. In addition, when the instrumental techniques are combined with sensory analysis, even more accurate information may be obtained regarding the overall wine aroma. This review discloses the state of the art of olfactometric methods and the analytical techniques used to investigate odor-active compounds such as one-dimensional gas chromatography, multidimensional gas chromatography, and comprehensive two-dimensional gas chromatography. The advances in knowledge of wine aroma achieved with the use of these techniques in the target and profiling approaches were also discussed.