## 3 Results and Discussion
### Wine Aroma Profile by Descriptive Sensory Analysis  
The attribute used to describe the Marquette wines after nine months of aging were displayed in Figure 1 with the mean score to evaluate the aroma intensity perceived by the trained panelists (n = 8). The most dominant aroma attributes in the CTL wine were alcohol, cider, and acetone, with mean scores of 3.8, 3.5, and 2, respectively, on a 15 cm line scale. The descriptor of fruit-related attributes were grape jelly, black cherry, black currant, and green apple, with mean scores of 2.9, 2.0, 2.0, and 1.2 out of 15 cm line scale, respectively. Marquette red wine is commonly associated with distinct flavor profiles of cherry, spice, black pepper, and berry [6]. The fruity notes were identified as consensus attributes by the panelists during the training session, including strawberry and black cherry. No descriptive sensory analysis has been conducted specifically on Marquette red wines in the past, which makes it challenging to compare.  
Based on the analysis of aroma compounds as reported in Table 2, the key aroma compounds in Marquette red wine after 9 months of aging were ethyl acetate, ethyl hexanoate, isobutanol, isoamyl alcohol, and 2-phenylethanol. These compounds are associated with odor descriptions such as nail polish remover, green apple, alcohol, fusel, and honey, respec  
Figure 1: Sensory analysis: the intensity of aroma attributes of Marquette red wines after nine months of aging. Different letters within the same attribute indicated statistically significant differences (\(p<0.05\)) by two-way ANOVA (Treatment across Panelist) following [PERSON]’s test.  
tively [4; 10]. The presence of these aroma compounds can partially explain the detection of aroma descriptors including acetone, green apple, alcohol, and honey by trained panelists in Figure 1. Although only trace amounts of other ethyl esters (e.g., ethyl octanoate) could be detected in Marquette wine by GC-MS, these various aroma compounds contribute to the perception of fruity and sweet odor descriptions such as strawberry and candy fruit [4; 10].  
The aroma attributes of Marquette wines made with different winemaking techniques significantly altered the intensity of certain attributes, including honey and green apple (\(p<0.05\)). The perception of a honey-like aroma could be attributed to certain aroma compounds such as 2-phenylethanol, 2-phenylethyled acetate, and 2-phenylacetaldehyde [7; 31], of which only 2-phenylethanol was detected during the measurement of volatile aroma compounds by GC-MS. Despite the lack of significant difference in the response ratio of 2-phenylethanol between treatment groups, the trained panelists perceived a stronger honey-like aroma note from the wine treated with ACE alone compared to the wines treated with ACE-PEC and ACE-RCE. Similarly, the ACE-treated wine exhibited a significantly higher intensity of green apple notes compared to the ACE-PEC and ACE-RCE wines, despite having a similar level of ethyl hexanoate as the control. This difference could be due to interactions between 2-phenylethanol or ethyl hexanoate and other aroma compounds, which might alter the overall perception of the green apple aroma. Given the complexity of wine aroma and the potential for synergistic effects, the presence or response ratio of a single compound does not always directly translate to sensory perception. Other volatile compounds, even in small amounts, may interact with 2-phenylethanol or ethyl hexanoate, changing their aromatic impact [32].  
Furthermore, the use of ACE in combination with macroating enzymes had no impact on the intensity of aroma descriptors, which was in line with the results of the GC-MS measurements. In addition, [PERSON] et al. [18] found that Shiraz red wine treated with ACE exhibited an elevated intensity of earthy/dusty flavor profiles. However, this characteristic was not detected in Marquette wine during the training session, which may be attributed to differences in the grape varieties used.