## 3 Results and Discussion
### Effect of Storage Conditions on Character Impact Odorants of Blueberries  
#### 3.2.1 AEDA Analysis by GC-MS-O  
GC-MS-O is a powerful technique that utilizes both human and mass spectrometry detectors to identify key odorants based on odor characteristics and mass spectra, and it is widely used to study food aromas and other applications as well [24]. In this study, we utilized SAFE extraction followed by GC-MS-O and AEDA to identify the odor potency of volatiles extracted from SC and the three storage treatments. Overall, it was found that most key odorants tended to have reduced flavor dilution factors (FDs) due to cold storage (S1) relative to SC, whereas there was a recovery (increase in FDs) following cold storage as storage progressed with the warmer storage treatments (S2 and S3) (Table 2). Among the key odorants were 4 esters, 7 aldehydes, 4 alcohols, 4 ketones, 5 terpen, and 10 miscellaneous compounds that contributed to the impression of overall blueberry aroma with FDs \(\geq\) 32-64. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Physicochemical Properties**} & \multicolumn{3}{c}{**Storage Treatments \({}^{a}\)**} \\  & **SC \({}^{b}\)** & **S1** & **S2** & **S3** \\ \hline Soluble solids (Brix) & 13.43 \(\pm\) 0.38 \({}^{\text{A}}\) & 13.27 \(\pm\) 0.06 \({}^{\text{A}}\) & 13.43 \(\pm\) 0.61 \({}^{\text{A}}\) & 13.90 \(\pm\) 0.45 \({}^{\text{A}}\) \\ Total acidity (\%) & 0.45 \(\pm\) 0.06 \({}^{\text{A}}\) & 0.41 \(\pm\) 0.02 \({}^{\text{AB}}\) & 0.35 \(\pm\) 0.01 \({}^{\text{B}}\) & 0.36 \(\pm\) 0.01 \({}^{\text{AB}}\) \\ Firmness (g/1 mm) \({}^{c}\) & 179.61 \(\pm\) 15.24 \({}^{\text{A}}\) & 164.19 \(\pm\) 10.69 \({}^{\text{A}}\) & 157.28 \(\pm\) 9.85 \({}^{\text{A}}\) & 127.89 \(\pm\) 1.39 \({}^{\text{B}}\) \\ \hline \hline \end{tabular} \({}^{a}\) Mean \(\pm\) S.D. from four replications. Values with different capital letters in a row are significantly different (\(p<\) 0.05), \({}^{b}\) SC = control, S1 = 3 weeks 1 \({}^{\text{C}}\), S2 = 3 weeks 1 \({}^{\text{C}}\) + 1 week 10 \({}^{\text{C}}\), S3 = 3 weeks 1 \({}^{\text{C}}\)C + 1 week 10 \({}^{\text{C}}\), S3 = 3 weeks 1 \({}^{\text{C}}\)C + 1 week 10 \({}^{\text{C}}\) + 2 d 20 \({}^{\text{C}}\). \({}^{\text{g}}\)/1 mm deflection.  
\end{table} 
Table 1: Levels of soluble solids, total acidity, and firmness of blueberries subjected to different storage conditions. \begin{table}
\begin{tabular}{l l l l l l l l l l l l l l l} \multicolumn{1}{c}{**Volatile Compounds**} & \multicolumn{1}{c}{**RI**} & \multicolumn{3}{c}{**Odaro Properties**} & \multicolumn{3}{c}{**IR**} & \multicolumn{3}{c}{**Strong-Termatives**} & \multicolumn{3}{c}{**Identification*** **} \\ \multicolumn{1}{c}{**Wokk**} & \multicolumn{1}{c}{**WJK**} & \multicolumn{1}{c}{**HW-S**} & \multicolumn{1}{c}{**SC**} & \multicolumn{1}{c}{**S1**} & \multicolumn{1}{c}{**SC**} & \multicolumn{1}{c}{**S2**} & \multicolumn{1}{c}{**S3**} & \multicolumn{1}{c}{**SC**} & \multicolumn{1}{c}{**SC**} & \multicolumn{1}{c}{**S1**} & \multicolumn{1}{c}{**S2**} & \multicolumn{1}{c}{**S3**} \\ \hline
2.3-Battraction & 821 & -5000 & Bunney, Daily, Milky & 4 & 128 & ND\({}^{\rm d}\) & 16 & 8 & 32 & 8 & 16 & RL, MC \\
3-Battraction & 900 & -500 & Fridge, Quark, Multiple, Output & 64 &  
Esters  
Esters are formed from carboxylic acids and alcohols in fruits during ripening and are responsible for the fruity note of blueberries [8]. Methyl 2/3-methylbutyrate and ethyl 2/3-methylbutyrate were identified in this study. Ethyl 3-methylbutyrate had the highest FD (4096, 1024) in SC, which decreased dramatically in S1 (8, 4) and then rose in both S2 and S3 (64, 32). On the other hand, ethyl-2-methylbutyrate was detected at the highest FD in S1 (128), followed by SC and S3, while it was not detected in S2. Methyl 2-methylbutyrate and methyl 3-methylbutyrate had equal FDs (1024) in SC; their FDs decreased in S1 (128 and 64), and then both further declined in S2 (8 and 64, respectively) followed by an increase in S3.