scholarly journals HS-SPME Combined with GC-MS/O to Analyze the Flavor of Strong Aroma Baijiu Daqu

Foods ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 116
Author(s):  
Zhe Wang ◽  
Song Wang ◽  
Pengfei Liao ◽  
Lu Chen ◽  
Jinyuan Sun ◽  
...  

Daqu has gained wide attention because it is an essential source of microorganisms and flavor in baijiu production. In this study, HS-SPME combined with GC-MS/O was used to analyze the volatile flavor components of Strong aroma baijiu Daqu. DI-GC-O was used to choose the best extraction fiber to extract the representative overall aroma profile of Daqu. A total of 139 compounds were identified in the six different maturity stages of Daqu, and these compounds are of different types and concentrations. HS-SPME combined with GC-MS/O was used to analyze the aroma active substances in the finished Daqu, and a total of 43 aroma compounds were identified. The OAVs of 21 aromatic compounds were calculated based on the quantitative analysis results of MHS-SPME. Eighteen compounds with OAVs ≥ 1 made significant contributions to the overall aroma of Daqu, including guaiacol, 4-ethyl-2-methoxy phenol, 2-ethyl-3,5-dimethylpyrazine, etc.

2018 ◽  
Vol 24 (4) ◽  
pp. 76-80
Author(s):  
Tae-Uk Kim ◽  
Sung-Hee Choi

2018 ◽  
Vol 24 (1) ◽  
pp. 72-76
Author(s):  
Tae-Uk Kim ◽  
Sung-Hee Choi

2021 ◽  
pp. 108201322110037
Author(s):  
Ercan Sarica ◽  
Hayri Coşkun

This study was aimed to determine the changes in kefir samples (CK and GK) made from cow’s and goat’s milk during frozen storage. The CK and GK samples were first stored at +4 °C for 14 and 21 days. Thereafter, all the samples were frozen at –35 °C for 24 h and kept at –18 °C for 45 days. There was no significant change in the fat, protein, acidity and pH values in both samples during the storage. The values of viscosity, WI and C* were higher in the CK samples while the syneresis value was higher in the GK samples throughout the frozen storage. The microorganisms ( Lactococcus spp., Lactobacillus spp., Leuconostoc spp., total mesophilic aerobic bacteria and yeasts) found in kefir made from goat's milk were more affected from the frozen storage. In both samples, the changes in organic acids and volatile flavor components were not significant during frozen storage, except acetic, citric and oxalic acids and acetaldehyde in GK sample. In addition, CK samples were preferred sensorially more by the panellists during frozen storage.


Author(s):  
Yuan Rao ◽  
Arno de Klerk

AbstractThe nitrogen-containing aromatic compounds found in the petrochemical industry are varied and extend beyond classes such as the anilines, pyrroles and pyridines. Quantification of these nitrogen-containing compounds that may occur in complex mixtures has practical application for quality assurance, process development and the evaluation of conversion processes. Selective detection of nitrogen-containing species in complex mixtures is possible by making use of gas chromatography coupled with a nitrogen phosphorous detector (GC-NPD), which is also called a thermionic detector. Despite the linearity of the NPD response to individual nitrogen-containing compounds, the response factor is different for different compounds and even isomers of the same species. Quantitative analysis using an NPD requires species-specific calibration. The reason for the sensitivity of the NPD to structure is related to the ease of forming the cyano-radical that is ionized to the cyanide anion, which is detected. The operation of the NPD was related to the processes of pyrolysis and subsequent ionization. It was possible to offer plausible explanations for differences in response factors for isomers based on pyrolysis chemistry. Due to this relationship, the NPD response can in the same way be used to provide information of practical relevance beyond its analytical value and a few possible applications were outlined.


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