# Consumer Characterization of Wet- and Dry-Aged Mutton Flavor Profile Using Check-All-That-Apply
## 4 Discussion
The dry- and wet-aged nutton volatile profile results are similar to recent studies comparing the volatile profiles of wet- and dry-aged beef with a general trend of increased concentrations of aldehydes, alcohols, ketones and pyrazines in the dry-aged profile relative to the wet-aged profile [21; 51]. Cooked sheep meat flavor results from a complex culmination of processes such as lipid degradation, proteolysis, Strecker degradation, thiamine degradation and the Maillard reaction, which produce a variety of alcohols, aldehydes, ketones, pyrazines, pyrroles, furrans, furfurrals and thiazoles, and each can contribute in varying degrees to the final flavor/ aroma of sheep meat [42; 52]. The generation of these compounds can be influenced by cooking time and temperature [53], pH of the meat [23], meat moisture content [12] and meat ageing conditions [54]. In this study, we found no significant difference in the TM% for wet- and dry-aged patties in either the raw or cooked state. While it was expected that the dry-aged patties would have lower TM than wet-aged, this result is not unusual, as it is understood that much of the moisture loss during dry-ageing is from the surface/trim of the primal cut and the internal meat is relatively protected [55]. [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] [21] also found no differences in the TM of wet- and dry-aged beef. The higher aldehyde concentration in the dry-aged samples suggests that more lipid oxidation has occurred than in the wet-aged samples, which is logical given that dry-aged meat does not have the same packaging protection afforded to wet-aged meat [56]. The FAME analysis supports this finding, with the higher concentration of the monounsaturated fatty acid cis-9-oleic acid methyl ester (the most abundant unsaturated FAME in our samples) found in the wet-aged patty compared to the dry-aged patty, indicating increased oxidation rates in the dry-aged patties [57]. These differences may be due to the increased exposure of dry-aged meat to oxygen in the atmosphere and or the extended cooking time required for the dry-aged patties, which is discussed further below. Pyrazines predominantly arise during the Maillard reaction [58] and they are responsible for roasted, toasted, fried and cooked meat aroma/flavors [42; 59]. It is logical that the dry-aged patties had higher levels of these compounds. Firstly, we found the dry-aged patties took longer to reach an internal temperature of 65 \({}^{\circ}\)C than the wet-aged patties (3 min 50 s vs. 3 min 5 s, respectively) and, therefore, they exhibited more surface browning. Secondly, the dry-aged patties had a higher pH than the wet-aged (Table 4) and [PERSON] and [PERSON] [23] have previously demonstrated that pyrazine formation is favored by increasing pH. Given there was no difference in the TM% between the raw dry- and wet-aged patties, it is proposed that the increased cooking time may be related to differences in thermal conductivity related to the proportion of bound water in the wet- and dry-aged patties; however, this cannot be confirmed. Caramel flavors in sheep meat have been associated with 2,3 butanedione, and 2,3 pentanedione [30]; unfortunately, the chromatographic system used for the volatile analysis was unable to resolve these compounds and we cannot confirm if they were present at higher levels in the dry-aged sample. Metallic flavors have been associated with nonanal, decanal 2,4 (E,E) heptadienal, 2 ethyl furan [30] and 1-octen-3-one [60]. We did not quantify 2,4 (E,E) heptadienal, but we found twice as much 2 ethyl furan in the dry-aged sample compared to the wet-aged sample, more than twice the concentration of nonanal in the dry-aged sample compared to the wet-aged sample, approximately 5 times the concentration of decanal in the dry-aged sample compared to the wet-aged, but three times more 1-octen-3-one in the wet-aged sample compared to the dry-aged.