# Consumer Characterization of Wet- and Dry-Aged Mutton Flavor Profile Using Check-All-That-Apply
## 2 Materials and Methods
### Chemical Analysis
#### 2.2.3 Semi Quantitative Determination of Volatiles  
Volatile analysis of freshly cooked wet- and dry-aged patties was based on the method of [PERSON] et al. [50] with a slight modification: the SPME extraction was carried out at 60 \({}^{\circ}\)C instead of 90 \({}^{\circ}\)C to represent the temperature of freshly cooked meat at the point of consumption. All reagents and standards were purchased from Sigma-Aldrich, Macquarie Park, New South Wales, Australia, and all chromatography supplies were sourced from Agilent, Mulgrave, Victoria, Australia. Certified standards included C7-C30 saturated alkanes mix (1000 ug/mL each compound, part no. 484451), 1,2 dichloromethane (part no. 240664-100 mL), 1-pentanol (part no. 76929), 2-methylpyrazine (part no. M75608),hexanal (part no. 18109), isovaleraldehyde (part no. 61848), dimethyl trisulfide (part no. 79592), 1-penten-3-ol (part no. 01984), 4-methyl-1-pentanol (part no. M66951), trans-2-heptenal (part no. 324140), isobutyraldehyde (part no. 240788), trans-2-octenal (part no. 52464), trans-2-nonenal (part no. 07592), octanal (part no. 52466), 1 octen-3-one (part no. 90963), 2-acetylpyrrole (part no. 247359), decanal (part no. D7384), nonanal (catalogue no. 442719), 4-methynonanoic acid (part no. W357405), p-cresol catalogue (part no. W233706), 4-ethoxyoctanoic acid (part no. W380008), 4-methyl octanoic acid (part no. W357502) and 3-methylindole (part no. 90961).  
The patties retained for volatile analysis were defrosted overnight in the vacuum packaging at 6 \({}^{\circ}\)C and cooked the next morning using the cooking method described in Section 2.1.4. Upon reaching an internal temperature of 65 \({}^{\circ}\)C, the patty was removed from the hot plate and cut in half; one half was weighed into a 500 mL capacity Nutribullet cup and an equal weight of >99.0% anhydrous sodium sulphate (Sigma-Aldrich part number 239313) was immediately added to the cup. The cup was then sealed using the blade assembly, and the sample homogenized on a 900 W Nutribullet blender model NB9-0507 (Target, Brisbane, Queensland, Australia) for 30 s. The remaining cooked patty was retained for moisture determination, as described in Section 2.2.1. Immediately after blending, 4 replicate 4 g aliquots of the homogenate were weighed into 20 mL capacity headspace vials (Agilent part number 5188-2753) and sealed with PTFE-lined screw caps (Agilent part number 5188-2759). An amount of 2 \(\mu\)L of 6.15 ng/mL 1,2 dichlorobenzene internal standard was added to a 150 \(\mu\)L vial insert positioned in the headspace vial to ensure fiber integrity throughout the analytical run. An external 1,2 dichlorobenzene standard of the same concentration was also run.  
Analysis of the sample headspace was conducted using an Agilent 5977B GC-MS in splitless mode, fitted with a PAL 3 RS1 120 autosampler (CTC instruments) and a HP-5 MS 30 m \(\times\) 0.25 \(\mu\)m film \(\times\) 0.25 mm internal diameter column with a helium flow of 1 mL/min. The samples were equilibrated at 60 \({}^{\circ}\)C with gentle agitation for 45 min before extraction. The headspace was then extracted for 45 min with a 2 cm DVB/CAR/PDMS SPME fiber (Sigma-Aldrich part no. 57299-U). The fiber was desorbed in the injector for 8 min at 250 \({}^{\circ}\)C. The GC oven was held at 40 \({}^{\circ}\)C for 5 min and then ramped up at 4 \({}^{\circ}\)C/min until the oven reached 280 \({}^{\circ}\)C, where it was held for 5 min. Total ion chromatogram (TIC) data were collected over the mass-to-charge ratio range of 33 to 230 m/z. Tentative compound identification was via retention time matching with the purchased external standards or published Kovats retention indices (LRI); compound identity was confirmed by spectral matching using the NIST library (version 17.0) or with the certified standard. Quantification of identified compounds was based on the selected ion peak areas. An assumed response factor of 1 peak area unit = 1 ng of compound with results expressed as ng/g of meat.