Comprehensive two‐dimensional gas chromatography mass spectrometry‐based untargeted metabolomics to clarify the dynamic variations in the volatile composition of Huangjiu of different ages

Abstract

Aging plays an important role in the formation of aroma characteristics of Huangjiu, a traditional Chinese alcoholic beverage. Comprehensive two‐dimensional gas chromatography mass spectrometry (GC×GC‐qMS)‐based untargeted metabolomics combined with a multivariate analysis was used to investigate the dynamic variations in the aroma profile of Huangjiu during aging process and to establish the relationship between the changing volatile metabolite profiles and the age‐dependent sensory attributes. A total of 144 volatile metabolites were identified by GC×GC‐qMS and 63 were selected as critical metabolites based on variable importance in projection values and p‐values. Based on the results of principal component analysis, orthogonal partial least‐squares discriminant analysis, and hierarchical clustering analysis, the samples of six different ages were divided into three groups: 1Y and 3Y samples, 5Y and 8Y samples, and 10Y and 15Y samples. The partial least‐squares analysis results further revealed the relationship between the aromas attributes and variations of these volatile compounds. The high esters, aldehydes, and lactones contents contributed to the high intensities of the sweet and ester aroma attributes of the aged Huangjiu, while the high alcohols and ethyl esters contents contributed to the alcoholic and fruity aroma attributes of the newly brewed Huangjiu. These results improve our understanding of the chemical nature of the aroma characteristics of aged Huangjiu. Practical Application Huangjiu is often labeled with its age as a measure of quality, which influences consumers’ choice. Dynamic variations in volatile compounds of Huangjiu during aging and its contribution to the aroma characteristics of Huangjiu were figured out, which will assist the industry to produce better quality aged Huangjiu for consumers.

Region of interest selection in heterogeneous digital image: Wine age prediction by comprehensive two-dimensional gas chromatography

“…In addition to the aforementioned compounds, only in the cluster of younger wines esters such as ethyl-11-hexadecenoate, ethyl coumarate, methyl 9-12-octadecadienoate I, methyl-icosa-11,14-dienoate, methyl 9-,12-octadecadienoate II, methyl decanoate, ethyl dodecanoate, ethyl pentadecanoate, methyl hexadecanoate, methyl benzoate, ethyl 9-decenoate, ethyl 4-acetoxybutanoate, benzyl acetate, and 2-phenylethyl acetate were identified. This is consistent with the observations that oxidative processes contribute to the reduction in specific ester levels ( Wang et al, 2019 ; Yu et al, 2022 ). Furthermore, the presence of specific furan derivatives, such as methyl-2-furancarboxaldehyde, has been revealed to play a role in distinguishing wines based on their age.…”

Metabolomic fingerprinting based on network analysis of volatile aroma compounds during the forced aging of Huangjiu: Effects of dissolved oxygen and temperature

“…Feature detection, retention time (RT) correction, and preliminary statistical analyses were carried out using XCMS online (XCMSOnline version 2.2.5; XCMS version 1.47.3; CAMERA version 1.26.0, the Scripps Center for Metabolomics, La Jolla, CA; https://xcmsonline.scripps.edu ). Raw data conversion, GC/MS spectra processing, set parameters, etc., were described in Yu et al ( 9 ). All chromatograms were simultaneously analyzed under the same conditions.…”

“…While metabolomics is concerned with characterizing the metabolome ( 22 ), metabolomics can be defined as the measurement of time-related changes (usually in a smaller set of metabolites) due to an intervention. To date, metabolomics has been successfully applied to the age-dependent characterization of Huangjiu ( 14 ) and other wines ( 9 , 30 , 40 – 43 ). Additionally, network analysis has proved to be a convenient method for visualizing and identifying key relationships between aroma compounds during the aging of some alcoholic beverages ( 23 , 44 , 45 ).…”

“…It is reported that compared with storage in stainless steel, pottery jars have a better oxygen permeability, and their higher thermal mass is less susceptible to changes in ambient temperature so as to keep a stable and suitable temperature of 5-20 • C (1, 2), but the model system studies, including oxygen permeability, are still lacking. Moreover, although changes in volatile aroma compounds, amino acids, sensory characteristics, and developments in analytical methods associated with the aging of Huangjiu have been reported (1)(2)(3)(4)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17), the overall mechanism has not been studied in detail.…”

Foods and Contaminants Analysis Using Multidimensional Gas Chromatography: An Update of Recent Studies, Technology, and Applications

“…For alcoholic beverages, in addition to typical wine and whiskey samples, local specialty alcoholic beverages, such as Baijiu (fermented sorghum or other grains), − Huangjiu (Chinese rice wine), , Tokaj wine (Slovakia), , and Syrah wine (Brazil), have been increasingly reported for MDGC applications over the past three years with fewer reports on tea, coffee, and fruit juice. According to Table , a majority of the reported applications aim to profile sample volatiles using GC×GC for general characterization or identify markers and/or evaluate the correlation between chemical compounds and organoleptic attributes of aroma using electronic nose (e-nose), 1DGC–O, and/or MDGC–O.…”