Objective To screen risk markers in the storage process of pork using ultra performance liquid chromatography-quadrupole-orbitrap high resolution mass spectrometry (UPLC-Q-Orbitrap HRMS) combined with chemometrics. Methods After sample pretreatment, UPLC-Q-Orbitrap HRMS was employed to detect metabolites in pork, obtaining high precision chromatographic and mass spectrometric data. Principal component analysis (PCA) was applied for dimensionality reduction to explore the distribution characteristics among samples. Orthogonal partial least squares-discriminant analysis (OPLS-DA) was then used to screen differential metabolites with a variable importance factor (VIP)>1.0. The statistical significance of the differences was further evaluated using T-tests (P<0.05), and the final key metabolites were confirmed by combining fold change analysis (fold change, FC>2 or FC<0.5). Results PCA revealed that storage temperature significantly influenced metabolite distribution in different pork cuts (loin, belly, and ham), with samples under different temperatures showing clear separation in the principal component space (total variance R2=0.861, predictive ability Q2=0.478). The OPLS-DA model further optimized the separation of intergroup differences (R2=0.811, Q2=0.653), making the impact of storage temperature on metabolite abundance and type more evident. The R2 and Q2 values of the real model were significantly higher than those of the permutation model, confirming the reliability of the analysis. Through screening conditions (VIP>1, P<0.05, FC>2 or FC<0.5) and structural verification, N-acetylputrescine and 6-methylquinoline were identified as risk markers. Conclusion UPLC-Q-Orbitrap HRMS combined with chemometrics effectively screens risk markers in pork during storage.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |