Table 1. The discriminating metabolites to distinguish beef sausage, dog meat sausage, and beef sausage containing dog meat

No Compounds VIP value Molecular formula Calculated m/z Retention time (min) Ionization
1 Trans-10-Heptadecenoic acid 2.33 C17H32O2 268.23959 19.764
2 N-Stearoyltyrosine 2.21 C27H45NO4 447.33303 16.539 +
3 L-Gamma-glutamyl-L-leucine 2.20 C11H20N2O5 260.13645 2.534 +
4 1-(beta-D-ribofuranosyl)thymine 2.20 C10H14N2O6 258.08439 1.015 +
5 Adenosine 2.18 C10H13N5O4 267.09584 1.203 +
6 (3beta,24R,24'R)-fucosterol epoxide 2.09 C29H48O2 428.36374 25.245 +
7 Acetyl-L-carnitine 2.08 C9H17NO4 203.11477 0.738 +
8 Isoleucine 2.07 C6H13NO2 131.09423 1.193 +
9 Diisobutyl adipate 2.06 C14H26O4 258.18235 16.372 +
10 L-Tyrosine 2.05 C9H11NO3 181.07334 1.048 +
11 Carnosine 2.02 C9H14N4O3 226.10560 0.681 +
12 DL-Glutamine 2.01 C5H10N2O3 146.06872 0.808 +
13 1,3-Dihydroxy-2-propanyl (11Z,14Z)-11,14-icosadienoate 1.99 C23H42O4 382.30643 32.041 +
14 5-Formamidoimidazole-4-carboxamide ribotide 1.95 C10H15N4O9P 366.05662 1.326
15 Stearic acid 1.95 C18H36O2 284.27081 22.085
16 α-Linolenoyl Ethanolamide 1.87 C20H35NO2 321.26532 19.48 +
17 N-Isobutyl-(2E,4E,14Z)-eicosatrienamide 1.80 C24H43NO 361.33273 21.231 +
18 1,6,7-Trimethylnaphthalene 1.78 C13H14 170.10929 12.224 +
19 (4S)-4-[(9Z,12Z,15Z)-9,12,15-Octadecatrienoyloxy]-4-(trimethylammonio)butanoate 1.75 C25H43NO4 421.31758 16 +
20 p-Cresylsulfate 1.73 C7H8O4S 188.01341 6.247
21 Hexanoylcarnitine 1.73 C13H25NO4 259.17761 6.431 +
22 1-Linoleoyl-2-Hydroxy-sn-glycero-3-PC 1.73 C26H50NO7P 519.33044 18.173 +
23 DL-Arginine 1.72 C6H14N4O2 174.11104 0.717 +
24 6-Hydroxypseudooxynicotine 1.71 C10H14N2O2 194.10613 13.965
25 Myristyl sulfate 1.68 C14H30O4S 294.18597 21.638
26 N,N-dimethyl-N-[(2,3,4,5-tetraphenylcyclopenta-2,4-dienyliden)methyl]amine 1.67 C32H27N 425.21600 14.527 +
27 Creatinine 1.66 C4H7N3O 113.05878 0.744 +
28 4-Indolecarbaldehyde 1.65 C9H7NO 145.05256 7.674 +
29 D-(+)-Proline 1.63 C5H9NO2 115.06316 0.791 +
30 3,6-Anhydro-1-O-palmitoylhexitol 1.63 C22H42O6 402.29712 19.627 -
31 Hypoxanthine 1.60 C5H4N4O 136.03810 0.939 +
32 DL-Lysine 1.56 C6H14N2O2 146.10508 0.631 +
33 Methionylleucine 1.55 C11H22N2O3S 262.13424 5.247 +
34 Arachidonic acid 1.52 C20H32O2 304.23911 19.474
35 Benzyl isobutyl ketone 1.51 C12H16O 176.11973 10.132 +
VIP>1.5, p-value<0.5.
VIP, variable importance for projection.