## 3 Results  
### Tartaric Stability and Tartaric Acid Reduction  
As described in the Materials and Methods section, tartaric stability was tested by a rapid discrimination method. Tartaric precipitation was not observed in the treated wines starting from the 13-day cold treatment, suggesting that the wines had gained tartaric stability. Compared with the traditional 15-day cold stabilization treatment in the wineries, this can save two days. The pH value of wines did not change significantly at the end of cold treatment, but compared with the control group, the pH values presented a decline in the cold treatment groups during subsequent bottle storage durations (Table 1), and the longer the bottle storage duration, the lower the pH values.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Cold Treatment** & **Without Storage in** & **Bottle Storage for 6** & **Bottle Storage for 12** \\
**Duration (Days)** & **Bottles** & **Months** & **Months** \\ \hline
0 & 3.16 \(\pm\) 0.01 aA & 3.13 \(\pm\) 0.02 aA & 3.03 \(\pm\) 0.02 aB \\
10 & 3.16 \(\pm\) 0.01 aA & 3.09 \(\pm\) 0.01 bB & 2.98 \(\pm\) 0.01 bC \\
11 & 3.15 \(\pm\) 0.01 aA & 3.08 \(\pm\) 0.02 bcB & 2.99 \(\pm\) 0.01 bC \\
12 & 3.17 \(\pm\) 0.02 aA & 3.09 \(\pm\) 0.01 bB & 3.01 \(\pm\) 0.04 abC \\
13 & 3.17 \(\pm\) 0.01 aA & 3.04 \(\pm\) 0.01 dB & 2.99 \(\pm\) 0.01 bC \\
14 & 3.15 \(\pm\) 0.01 aA & 3.05 \(\pm\) 0.01 dB & 2.99 \(\pm\) 0.01 bC \\
15 & 3.15 \(\pm\) 0.01 aA & 3.06 \(\pm\) 0.01 cdB & 2.98 \(\pm\) 0.02 bc \\ \hline \hline \end{tabular}  
*Mean \(\pm\) sd\({}^{\circ}\)(_n_ = 3) were shown in the table. Different lowercase letters represent significant differences in the pH values between different groups at the same bottle-storage period. Different capital letters represent significant differences in the pH values among bottle-storage durations for the same treatment group (Duncan, \(p\) < 0.05).  
\end{table}
Table 1: Effects of cold treatment duration and bottle storage duration on wine pH value.  
One-way and two-way ANOVA were carried out, and the results showed that compared with the control group without cold treatment, cold stabilization treatments for 10-15 days (expressed as T10-T15) reduced tartaric acid and succinic acid concentrations significantly by approximately 10.85-15.97% and 11.32-24.12%, respectively. As expected, there was no significant variation between different treatment groups on citric acid and malic acid concentrations during the whole bottle-storage duration. Concerning acetic acid and lactic acid, the effect of treatments appeared to be temporary and inconsistent before and after bottle storage (Table 2).  
During the entire bottle storage, the concentrations of tartaric acid, citric acid, and lactic acid remained stable. The concentration of malic acid in most treatment groups, except for T12 and T15, and the concentration of succinic acid in all groups decreased significantly after bottle storage. In contrast, the concentration of acetic acid in all treatment groups significantly increased after bottle storage.  
The results of the two-way ANOVA analyses showed that only the concentrations of acetic acid and succinic acid were significantly affected by the interaction of cold stabilization duration and bottle-storage duration, whose concentrations were relatively lower than those of other organic acids in the wines.