## 3 Results and Discussion  
### Physicochemical Characteristics Analysis  
The physicochemical parameters of the six basic components of rose-based functional beverage fermented by different strain groups were analyzed (Table 1). Microbial growth during fermentation necessitates the consumption of sugars for conversion into other metabolites. In all three fermentation groups, the inoculated microorganisms exhibited robust growth, maintaining cell counts above 7.37-8.46 log CFU/mL after 24 h, indicating that the rose beverage substrate was conducive to the growth of both lactic acid bacteria and yeast. The total reducing sugar content in the unfermented control group was 36.52 g/L. Following fermentation, a significant decrease in total reducing sugar was observed, with reductions of 63.39% in the SFR group, 79.46% in the LFR group, and 88.80% in the LSFR group. This reduction in sugar content correlated with the observed changes in pH. After 3 days of fermentation, the pH value of the rose beverages significantly decreased, which is primarily attributed to the production of organic acids by the lactic acid bacteria strains. Following fermentation, the free amino acid (FAA) content in the rose beverage increased significantly, by 6.75-fold in LFR samples and 4.96-fold in LSFR samples. This observation aligns with previous studies, which reported that increased amino acid content during fermentation is associated with the decomposition of proteins and peptides by microbial peptidases and autolysis of lactic acid bacteria [34; 35]. In contrast, the total amino acid content in the rose beverage fermented solely by _S. cerevisiae_ (SFR) was significantly reduced. Amino acids are known to serve as important precursors for the formation of volatile compounds that contribute to the aroma of beverages during yeast metabolism [36]. Therefore, it is plausible that the conversion of amino acids into alcohols, aldehydes, ketones, and other flavor compounds contributed significantly to this observed reduction in the SFR group. Fermentation by different microorganisms can lead to significant variations in the color of rose beverages. We therefore analyzed the chromatic intensity and trichromatic values of the fermented rose beverages. The results showed that the chromatic intensity was lowest in the SFR group (0.87) and highest in the LFR group (1.02). This suggests that the higher chromatic intensity in the LFR group may be related to the formation of polymer pigments following \(L\). plantarum fermentation, potentially influenced by the \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Indexes** & **LFR** & **SFR** & **LSFR** & **UFR** \\ \hline pH & 3.31 \(\pm\) 0.006  & 4.41 \(\pm\) 0.020  & 3.56 \(\pm\) 0.006  & 4.89 \(\pm\) 0.006  \\ Total sugar (g/L) & 7.5 \(\pm\) 0.301  & 13.37 \(\pm\) 1.367  & 4.09 \(\pm\) 0.784  & 36.52 \(\pm\) 0.410  \\ Viable counts (log CFU/mL, 0 h) & 6.48 \(\pm\) 0.010  & 6.79 \(\pm\) 0.018  & 6.52 \(\pm\) 0.023  & 0  \\ Viable counts (log CFU/mL, 24 h) & 8.46 \(\pm\) 0.012  & 7.37 \(\pm\) 0.085  & 8.46 \(\pm\) 0.053  & 0  \\ Total amino acid content (mg/L) & 1628.38 \(\pm\) 2.3810  & 165.27 \(\pm\) 4.193  & 1255.23 \(\pm\) 22.288  & 209.97 \(\pm\) 9.053  \\ Chromaticity strength & 1.02 \(\pm\) 0.022  & 0.87 \(\pm\) 0.009  & 0.91 \(\pm\) 0.003  \\ L* & 57.10 \(\pm\) 0.590  & 62.51 \(\pm\) 0.076  & 61.57 \(\pm\) 0.368  & 61.53 \(\pm\) 0.284  \\ a* & 53.31 \(\pm\) 0.856  & 30.22 \(\pm\) 0.012  & 44.19 \(\pm\) 0.387  & 27.51 \(\pm\) 0.234  \\ b* & 28.74 \(\pm\) 0.236  & 38.85 \(\pm\) 0.480  & 27.99 \(\pm\) 0.176  & 45.39 \(\pm\) 0.320  \\ Total phenols (mg/mL) & 2.64 \(\pm\) 0.050  & 2.47 \(\pm\) 0.020  & 2.75 \(\pm\) 0.020  & 2.22 \(\pm\) 0.06  \\ Total flavonoids (mg/mL) & 0.25 \(\pm\) 0.010  & 0.23 \(\pm\) 0.006  & 0.25 \(\pm\) 0.004  & 0.2 \(\pm\) 0.010  \\ \hline \hline \end{tabular} Note: Values with different lowercase letters in superscript in the same line were significantly different at \(p<0.05\) by LSD in ANOVA.  
\end{table}