# Development of Pretreatment Approaches for Authentic Representation of Tea Infusion Aroma
## 3 Results Analysis
### Deionized water  
#### 3.2.2 Exploration of High-Fidelity Aroma Extraction Conditions  
The above findings demonstrated that high-temperature, long-duration extraction conditions can easily distort tea aroma, necessitating the identification of more suitable extraction parameters to mitigate such adverse effects. Based on the established aroma extraction conditions, sensory fidelity was compared. The control groups for pure water and ionized water systems were brewed for 4 min at a tea-to-water ratio of 1 g:50 mL. The effects of varying tea-to-water ratios, extraction temperatures, and durations on sensory fidelity were investigated, as illustrated in Figure 4.  
Figure 4A reveals that as the tea-to-water ratio increased, the aroma profiles of both systems remained relatively similar before and after extraction, with changes in each individual aroma attributes not exceeding 1.67 points. This suggested that a tea-to-water ratio within 1g:10 mL had minimal impact on the overall aroma characteristics. Figure 4B shows that at an extraction temperature of 30 \({}^{\circ}\)C, changes in aroma attributes were limited to 0.67 points, and the aroma profiles of both systems closely resembled their respective CKs. At 45 \({}^{\circ}\)C, the pure water system exhibited minor changes (all within 1.00 point), while the ionized water system began to deviate from its CK, particularly due to a sharp increase (3.00 point) in sweet aroma. At 60 \({}^{\circ}\)C, both systems showed significant divergence from their CKs, with pronounced changes in aroma attributes. For instance, in the pure water system, tender aroma decreased by 2.34 points, and stuffy and ripeness flavor increased by 5 points. In the ionized water system, chestnut aroma decreased by 3.00 points, while sweet aroma and metallic off-flavor increased by 3.33 and 2.33 points, respectively. Even with a short extraction time at 30 min, high temperatures markedly altered the aroma profiles, intensifying stuffy and ripeness flavor in the pure water system and metallic off-flavor and sweet aroma in the ionized water system. Thus, an extraction temperature of 30 \({}^{\circ}\)C was more conducive to preserving the authentic aroma of both systems. Figure 4C indicates that prolonged extraction time had little effect on the pure water system, whereas the ionized water system showed noticeable changes only after 60 min. For extraction times of 30 or 45 min, changes in each aroma attributes were within 0.67 points, indicating a negligible  
Figure 3: Aroma fidelity evaluation under maximum enrichment extraction conditions of tea aroma compounds (“**” indicates the level of significance. “**” means \(p<0.05\); “***” means \(p<0.01\)).  
impact on fidelity. At 60 min, the pure water system exhibited a slight increase in chestnut aroma (0.83 points) and stuffy and ripeness flavor (0.67 points), while the ionized water system showed a significant reduction in chestnut aroma (2.34 points) and increases in sweet aroma (2.33 points) and metallic off-flavor (1.66 points). Therefore, an extraction time of 30-45 min minimized changes in overall aroma profiles.  
In summary, an extraction temperature of 30 \({}^{\circ}\)C and a duration of 30-45 min enhanced the fidelity of pure/ionized water-infused aroma, while the tea-to-water ratio has a less significant impact.