Real-Time Profiling and Distinction of Lipids from Different Mammalian Milks Using Rapid Evaporative Ionization Mass Spectrometry Combined with Chemometric Analysis

Abstract

The price of mammalian milk from different animal species varies greatly due to differences in their yield and nutritional value. Therefore, the authenticity of dairy products has become a hotspot issue in the market due to the replacement or partial admixture of high-cost milk with its low-cost analog. Herein, four common commercial varieties of milk, including goat milk, buffalo milk, Holstein cow milk, and Jersey cow milk, were successfully profiled and differentiated from each other by rapid evaporative ionization mass spectrometry (REIMS) combined with chemometric analysis. This method was developed as a real-time lipid fingerprinting technique. Moreover, the established chemometric algorithms based on multivariate statistical methods mainly involved principal component analysis, orthogonal partial least squares-discriminant analysis, and linear discriminant analysis as the screening and verifying tools to provide insights into the distinctive molecules constituting the four varieties of milk. The ions with

Rapid evaporative ionization mass spectrometry: A survey through 15 years of applications

“…As already mentioned in the introduction section, the coupling of REIMS with an electric soldering iron as a contact heating probe facilitated the sampling of liquid matrices, as demonstrated for the analysis of milk [21] and virgin olive oil [23]. All these applications demonstrated the potential of REIMS for the analysis of food products, independently from their physical state and nutritional composition.…”

“…A valid alternative to investigate liquid and poorly conductive samples was also presented by Wang et al, that combined the REIMS source with an electric soldering iron as a contact heating device [20]. This instrumental setup has been mostly used in the food field for the analysis of honey, milk, sorghum, olive oil, and cream [20][21][22][23][24] but was also employed for textile and clinical applications for the analysis of lather products and plasmalogen-loaded zein • Poor discrimination of isomers or isobars nanoparticles, respectively [25,26]. Liu and colleagues performed a clear comparison between iknife and soldering iron sampling devices in terms of signal intensity for the ambient ionization of sorghum powders, in order to assess that any ion enhancer is necessary when using the soldering iron even in the case of not conductive samples, while an insufficient aerosol is generated by iknife [22].…”

“…As already mentioned in the introduction section, the coupling of REIMS with an electric soldering iron as a contact heating probe facilitated the sampling of liquid matrices, as demonstrated for the analysis of milk [21] and virgin olive oil [23].…”

Applications of ambient ionization mass spectrometry in 2022: An annual review

“…79 With similar efforts to improve the authenticity and quality of animal products, REIMS has similarly been used for the authentication of shrimp 80 and beef, 81 for the characterization of aged tuna products 82 and fish speciation, 83 and for milk authentication. 84 Numerous other AIMS techniques have been demonstrated as potential tools in the authentication of food products, including ASAP for the authentication of Manuka honey 85 and Chinese teas, 86 DART for the discrimination of milk products 87 and edible insects, 88 DESI for the characterization of plant and animal-derived milk, 89 and desorption APCI for vanilla characterization. 90 Bertella et al performed a comparison of multiple AIMS techniques for wine authentication, evaluating PS, DBD, and LTP-MS whilst comparing the results to a standard ESI-MS method.…”

“…REIMS has also been used for the chemical prediction of beef palatability, studying the chemical variation associated with factors such as flavour, juiciness, and tenderness, all of which will be important in the authentication 79 . With similar efforts to improve the authenticity and quality of animal products, REIMS has similarly been used for the authentication of shrimp 80 and beef, 81 for the characterization of aged tuna products 82 and fish speciation, 83 and for milk authentication 84 . Numerous other AIMS techniques have been demonstrated as potential tools in the authentication of food products, including ASAP for the authentication of Manuka honey 85 and Chinese teas, 86 DART for the discrimination of milk products 87 and edible insects, 88 DESI for the characterization of plant and animal‐derived milk, 89 and desorption APCI for vanilla characterization 90 .…”