To establish a technical method based on untargeted metabolomics, analyze the differences in metabolites after blending glacial acetic acid (ethanol fermentation method) in brewed vinegar, and screen characteristic markers for adulteration identification.
Taking Ninghuafu traditional aged vinegar as the research object, ultra performance liquid chromatography-quadrupole-Orbitrap tandem mass spectrometry(UPLC-Q-Orbitrap MS/MS) was used to collect metabolite components of vinegar samples with different dilution degrees (acidity ranging from 6.0%–8.0%). Combined with multivariate statistical analysis methods such as principal component analysis and partial least squares discriminant analysis, differential metabolites were screened and identified.
A total of 5 markers with significantly differences were identified, including oleamide,N-benzyl-linoleamide, triethylcitrate, dibutyladipate and monopalmitin. When the content of oleamide was significantly lower than 479.99 µg/kg, and the content of N-benzyl-linoleamide, triethylcitrate, dibutyladipate and monopalmitin were higher than the levels in traditional brewed vinegar (0.92, 0.89, 10.82 µg/kg and 56.56 mg/kg,respectively), these compounds could effectively distinguish whether the vinegar had been adulterated. The content of oleamide showed a significant downward trend with increasing glacial acetic acid concentration, with a content of 39.40 µg/kg in samples with an acidity of 8.0%. N-benzyl-linoleamide (9.50 µg/kg) reached peaks in the sample groups 7.0% acidity. Triethylcitrate (4.22 µg/kg), monopalmitin (129.26 mg/kg) and dibutyladipate (27.66 µg/kg) in the 8.0% acidity sample reached 4.75, 2.29 and 2.56 times that of traditional vinegar.
The untargeted metabolomics method based on UPLC-Q-Orbitrap MS/MS established in this study screens out significantly differential biomarkers, which provides a novel technical approach for the authenticity identification of vinegar, and guarantees the quality of vinegar products as well as protects the health rights and interests of consumers.
| 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 |