## 2 Materials and Methods
### Chromatography and Mass Spectrometry of ISP Extracts  
The brine and meat extract samples were prepared using solid-phase extraction (SPE), according to [PERSON] et al. [19]. The Supelclean LC-18 SPE Tube (45 \(\upmu\)m, 60 A, 3 mL) columns by Supelco (Bellefonte, PA, USA) was used. Samples were dissolved in 0.1% (\(\sigma\)/\(v\)) of trifluoroacetic acid (TFA) in HPLC-suitable water (Sigma Aldrich, St. Louis, MO, USA, cat. no. 270733). The columns were initially conditioned using 6 mL 0.1% (\(v\)/\(v\)) TFA in HPLC-suitable acetonitrile (ACN) gradient grade (Sigma Aldrich, cat. no. 34851) and equilibrated using 6 mL 0.1% (\(v\)/\(v\)) TFA in water. Samples with a flow rate of 1-2 drops per second were loaded on columns, and then washed five times using 3 mL portions of 0.1% (\(v\)/\(v\)) of (TFA) in water. Elution was performed using 5 mL of 0.1% TFA in acetonitrile. Eluates were evaporated using a vacuum concentrator ([PERSON], Osterode am Harz, Germany). The remaining pellets were dissolved in water, lyophilized, and stored at \(-\)86 \({}^{\circ}\)C before further analysis. Samples were dissolved in 300 \(\upmu\)L of buffer with pH 6.6, containing 0.1 M BIS-TRIS and 4 M urea. Samples were reduced by the addition of 20 \(\upmu\)L of 2-mercaptoethanol, followed by shaking for 1 h at room temperature, 1000 \(\times\) min\({}^{-1}\) (ThermoMixer\({}^{0}\), Eppendorf, Hamburg, Germany). The reaction was stopped by the addition of 680 \(\upmu\)L of 6 M urea in water (pH 2.2 adjusted using TFA), and samples were centrifuged (10 min, 4 \({}^{\circ}\)C, 10,000\(\times\)\(g\)). The final concentration was 1 mg \(\times\) mL\({}^{-1}\) for brine samples, and 3 mg \(\times\) mL\({}^{-1}\) for meat samples [20]. RP-HPLC analyses were carried out using the Shimadzu (Tokyo, Japan) assembly-containing controller CBM-20A, the DGU-20A5 degasser, the SIL-20 AC HT autosampler, two LC-20 AD pumps, the CTO-10 AS thermostat, and the SPD-M20A photodiode array detector. The assembly was equipped with the Jupiter Proteo (Phenomenex, Torrance, CA, USA) C18 column, 250 \(\times\) 2 mm, with a particle size of 5 \(\upmu\)m, and pore size of 300 A. The mobile phase consisted of solvents A and B--0.075% (\(v\)/\(v\)) TFA in water, and 0.1% (\(v\)/\(v\)) TFA in ACN,respectively, to minimize baseline drift [21]. The following gradient of solvent B was applied: analysis: 5-20% from 0.00 to 30.00 min; 20-70% from 30.01 to 60.00 min; column washing: from 70-100% from 60.01 to 61.00 min; 100% from 61.01 to 75.00 min; column equilibration: 100-5% from 75.00 to 76.00 min; 5% from 76.01 to 90.00 min. The injection volume was 50 \(\upmu\)L, flow rate: 0.2 mL \(\times\) min\({}^{-1}\), and column temperature: 30 \({}^{\circ}\)C. Chromatograms were acquired at wavelength 220 nm. Data were collected and processed using Lab Solution (LC Solution) software (Shimadzu). RP-HPLC analyses were replicated twice. Samples were reduced using the same procedure as previously. Before analysis, samples were purified using C18 ZipTips (Merck Millipore, Burlington, VT, USA) with bed capacity of 0.6 \(\upmu\)L, according to provider instruction. The resin was washed twice using 10 \(\upmu\)L ACN (wetting solution), and twice using 10 \(\upmu\)L of 0.1% (\(v/v\)) TFA in water (equilibration solution). The samples were loaded by passing them ten times through ZipTip. Then, the ZipTip was washed five times with equilibration solution. Finally, 1.5 \(\upmu\)L of 50% acetonitrile in water with 0.1% TFA addition (\(v/v\)) in clear tubes was aspirated and dispensed through the ZipTip for sample elution. Matrix-Assisted Laser Desorption Ionization-Time of Flight (MALDI-ToF) mass spectrometry was carried out using MALDI-7090 (Kratos, Shimadzu Group, Manchester, UK), according to provider instruction.