Sensorial Impact and Distribution of 3-Methyl-2,4-nonanedione in Cognacs and Spirits

Characterization of the key odorants in goji wines in three levels of sweetness by applications of sensomics approach

The correlations and differences of the key odorants were systematically conducted among three sweetness of goji wines by the sensomics approach. After aroma (extract) dilution analysis, 67, 67, and 66 odorants were screened in sweet goji wine, semi-dry goji wine, and dry goji wine, in which, 63 odorants were identified in all goji wines. Determination of 53 odorants revealed a total of 30 odorants with the concentrations surpassing their olfactory thresholds. Overall, the odor activity values (OAVs) of ketones decreased, while esters, alcohols, phenols, and aldehydes increased with the decrease in sweetness in goji wine samples. Nevertheless, (E)-β-damascenone, trans- and cis-whisky lactones, and 3-methyl-2,4-nonanedione, evoked cooked apple-like, coconut-like, and hay-like odor impressions in goji wines and showed the highest OAVs. A reliable evaluation of the aroma contributions was executed as aroma recombinations and suggested a successful evaluation of key odorants in goji wines.

Aroma determination in alcoholic beverages: Green MS-based sample preparation approaches

Aroma determination in alcoholic beverages has become a hot research topic due to the ongoing effort to obtain quality products, especially in a globalized market. Consumer satisfaction is mainly achieved by balancing several aroma compounds, which are mixtures of numerous volatile molecules enclosed in challenging matrices. Thus, sample preparation strategies for quality control and product development are required. They involve several steps including copious amounts of hazardous solvents or time-consuming procedures. This is bucking the trend of the ever-increasing pressure to reduce the environmental impact of analytical chemistry processes. Hence, the evolution of sample preparation procedures has directed towards miniaturized techniques to decrease or avoid the use of hazardous solvents and integrating sampling, extraction, and enrichment of the targeted analytes in fewer steps. Mass spectrometry coupled to gas or liquid chromatography is particularly well suited to address the complexity of these matrices. This review surveys advancements of green miniaturized techniques coupled to mass spectrometry applied on all categories of odor-active molecules in the most consumed alcoholic beverages: beer, wine, and spirits. The targeted literature consider progresses over the past 20 years.

Characterization of Key Aging Aroma Compounds in Aged Jiangxiangxing Baijiu and Their Formation Influencing Factors during the Storge Process

Long-term storage Baijiu has an appealing sensory property, yet the chemical makeup is rarely reported. This study investigated a 30-year-old Jiangxiangxing (JXX) Baijiu and recognized and measured 69 aroma compounds. 3-Methyl-2,4-nonanedione (2.76 μg/L), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (HDMF, 46.2 μg/L), 2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone (HEMF, 61.7 μg/L), and piperitone (3.66 μg/L) were detected for the first time in Baijiu. Compared with 3-year-old JXX Baijiu, 24 compounds were significantly higher in the 30-year-old, mainly including furans, pyrazines, and aromatics. Notably, 4,5-dimethyl-3-hydroxy-2(5H)-furanone (sotolon), HDMF, HEMF, vanillin, acetovanillone, and alkyl pyrazines in 30-year-old JXX Baijiu were 2-7 times higher than those of a 3-year-old, and they increased steadily during aging for 3, 15, and 30 years, assumed to be associated with the aging aroma. Following 24 months of storing JXX Baijiu under different conditions, the pottery significantly promoted the synthesis of sotolon, HDMF, HEMF, and alkyl pyrazines. These findings suggest that pottery is a potential catalyst for enhancing aged Baijiu.

Distribution and Sensory Impact of (2E,4E,6Z)-nonatrienal and Trans-4,5-epoxy-(E)-2-decenal in Wines and Spirits

This study reports the distribution of (2E,4E,6Z)-nonatrienal (1) and trans-4,5-epoxy-(E)-2-decenal (2) in wines and spirits. We validated a quantification method using solid-phase extraction (SPE) and negative chemical ionization (NCI, NH3) gas chromatography-mass spectrometry (GC-MS) analysis. Both were identified for the first time in wines and spirits from different grape varieties and raw materials. Their olfactory detection thresholds (ODTs) were 16 and 60 ng/L, respectively. Analysis of 66 wines showed that the highest levels of (1) (441.3 ng/L) and (2) (386.5 ng/L) were found in red and white wines, respectively. At these levels, they modify the balance of the fruity expression of red (fresh to cooked fruits) and white (vegetal/green hazelnut nuance) wines. Similar quantitative and sensory analyses were conducted in spirits. With ODT estimated at 500 and 400 ng/L and concentrations ranging from trace amounts to 1.1 and 2.4 μg/L respectively, (1) and (2) can contribute directly to the aroma of spirits.

Separation techniques for manufacturing fruit spirits: From traditional distillation to advanced pervaporation process

Separation process is one of the key processes in the production of fruit spirits, including the traditional distillation method and the new pervaporation membrane method. The separation process significantly determines the constituents and proportions of compounds in the fruit spirit, which has a significant impact on the spirit quality and consumer acceptance. Therefore, it is important and complex to reveal the changing rules of chemical substances and the principles behind them during the separation process of fruit spirits. This review summarized the traditional separation methods commonly used in fruit spirits, covering the types, principles, and corresponding equipment of distillation methods, focused on the enrichment or removal of aroma compounds and harmful factors in fruit spirits by distillation methods, and tried to explain the mechanism behind it. It also proposed a new separation technology for the production of fruit spirits, pervaporation membrane technology, summarized its working principle, operation, working parameters, and application in the production of fruit spirits, and outlined the impact of the separation method on the production of fruit spirits based on existing research, focusing on the separation of flavor compounds, sensory qualities, and hazard factors in fruit spirits, along with a preliminary comparison with distillation. Finally, according to the current researches of the separation methods and the development requirement of the separation process of fruit spirits, the prospect of corresponding research is put forward, in order to propose new ideas and development directions for the research in this field.

A review on flavor of Baijiu and other world-renowned distilled liquors

The flavor characteristics of distilled liquors significantly affect consumer acceptance and adoption. Therefore, odorants that contribute to sensory properties have received more attention. The odorants depend on the operating parameters, such as raw materials and ingredients, manufacturing process and maturing circumstances. This review summarized the odorants in the Baijiu and other world-renowned distilled liquors. Especially, the contribution of the odorants to the dominant aroma attributes is given more attention. The variations in the constituents and contents of odorants among the liquors are discussed comprehensively. In general, further research is still needed on the interaction mechanism between the odorants and sensory properties of distilled liquors.