## 3 Results
### GC-E-Nose Analysis of Aroma Differences in Greengage Alcoholic Beverage by Different S. cerevisiae  
GC-E-Nose is a novel aroma analysis technology that provides a more comprehensive detection of volatile compounds compared to traditional sensor-based electronic noses, offering greater sensitivity and speed [26]. In this study, aroma fingerprint profiles of the GAB were established using signals collected from MXT-5 and MXT-1701 columns. The representative fingerprint profiles of different fermentation groups (MXT-5) are shown in Figure 1A. The results indicated that the flavor compound content in the NM-8 fermentation group is significantly lower than that in the other three fermentation groups at 20-30 s and 130-140 s.  
To establish a visual recognition model that distinguishes between different fermentation groups and to analyze the differences among them, discriminant factor analysis (DFA) was performed. The total discriminant factor value of the DFA was 99.019%, which is sufficient to explain the differences among the samples. As shown in Figure 1B, the  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Physicochemical** & **SY** & **ET008-c54** & **EC-1118** & **NM-8** \\
**Parameters** & & & & \\ \hline Reducing sugar (g\(\cdot\)L\({}^{-1}\)) & 8.62 \(\pm\) 0.59 a & 16.65 \(\pm\) 1.12 b & 25.45 \(\pm\) 1.11 c & 17.63 \(\pm\) 0.63 b \\ Sugar utilization (\%) & 0.87 \(\pm\) 0.01 d & 0.83 \(\pm\) 0.01 b & 0.78 \(\pm\) 0 a & 0.77 \(\pm\) 0.01 a \\ Total acid (g\(\cdot\)L\({}^{-1}\)) & 10.04 \(\pm\) 0.11 ab & 8.42 \(\pm\) 1.95 a & 10.3 \(\pm\) 0.23 ab & 10.56 \(\pm\) 0.26 b \\ Alcohol degree (\%\(v/v\)) & 11.78 \(\pm\) 0.08 c & 11.17 \(\pm\) 0.07 b & 10.53 \(\pm\) 0.05 a & 10.45 \(\pm\) 0.1 a \\ pH & 2.45 \(\pm\) 0.02 b & 2.44 \(\pm\) 0.01 ab & 2.41 \(\pm\) 0.02 a & 2.45 \(\pm\) 0.02 b \\ Color intensity & 0.61 \(\pm\) 0.01 b & 0.67 \(\pm\) 0.02 c & 0.56 \(\pm\) 0.01 a & 0.57 \(\pm\) 0.01 a \\ Color tonality & 2.43 \(\pm\) 0.11 b & 2.97 \(\pm\) 0.07 c & 1.93 \(\pm\) 0.03 a & 1.97 \(\pm\) 0.08 a \\ \hline \hline Color intensity = A420 + A520 + A620. Color tonality = A420/A520. Values with different letters (a–d) in the same row indicated significant differences (\(p<0.05\)). & & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Results of physiochemical characteristics of GAB fermented by different _Saccharomyces cerevisiae_ strains.  
Figure 1: **(A)** Gas chromatography electronic nose (GC-E-Nose) fingerprint profiles of different fermentation groups (MXT-5). The red box in (**A**) represents that the Intensity in the NM-8 fermentation group is significantly lower than that in the other three fermentation groups at 20–30 s and 130–140 s. (**B**) Discriminant function analysis (DFA) results based on GC-E-Nose.  
four fermentation groups were located in four distinct quadrants. The points corresponding to the SY, EC-1118, NM-8, and ET008-c54 fermentation groups fall within the ranges of \(-24.12\)\(-\)\(-\)\(-\)\(22.91\), \(-6.79\)\(-\)\(-\)\(4.55\), \(18.29\)-\(20.17\) and \(8.64\)-\(12.24\) on DF1, respectively. The distribution of the four fermentation groups along DF1 showed significant differences, particularly between the SY and NM-8 fermentation groups, indicating substantial differences in their over all aroma. The combined results of GC-E-Nose and DFA analysis confirmed that the VOCs of the GAB fermented by the four _S. cerevisiae_ strains exhibited obvious differences.