Establishing an untargeted-to-MRM liquid chromatography–mass spectrometry method for discriminating reconstituted milk from ultra-high temperature milk

Effects of the Oxygen Content and Light Intensity on Milk Photooxidation Using Untargeted Metabolomic Analysis

“…Untargeted Profiling by UPLC−Triple-TOF-MS. Metabolite extraction was based on previously published methods. 17,18 First, 2 mL of milk was added to a 15-mL centrifuge tube (Corning, USA) and centrifuged at 10,000g and 4 °C for 30 min to remove the fat layer (Sigma, Germany). Next, precooled acetonitrile (4 mL) was added to the skim milk, and the mixture was vortexed for 5 min and centrifuged at 10,000g and 4 °C for 30 min to precipitate the protein.…”

“…18,22 The metabolites with relative standard derivations below 20% in the QC samples were used for the normalization and analysis. 17,23 One-way ANOVA and chemometric methods were applied to identify potential biomarkers using MetaboAnalyst software (http://www.metaboanalyst.ca) and SIMCA 14.1 software (Umetrics, Sweden). The preprocessed data were normalized by the QC samples, logarithmically transformed, mean-centered, and divided by the square root of the standard deviation of each variable (Pareto scaling).…”

“…The data were filtered with the following parameters: signal-to-noise ratio above 3, intensities of peaks above 100 counts, mass width of 0.02 Da, and mass tolerance of 0.02 Da. The metabolites with >50% missing values were removed, and the remaining missing values were replaced with a low value (half of the minimum positive value in the raw data). , The metabolites with relative standard derivations below 20% in the QC samples were used for the normalization and analysis. , One-way ANOVA and chemometric methods were applied to identify potential biomarkers using MetaboAnalyst software () and SIMCA 14.1 software (Umetrics, Sweden). The preprocessed data were normalized by the QC samples, logarithmically transformed, mean-centered, and divided by the square root of the standard deviation of each variable (Pareto scaling) .…”

Metabolites in Milk after Enrofloxacin Treatment and Their Persistence to Temperature

“…Such processes are addressed to ensure milk safety and preservation by destroying the possible pathogens that may be present. Regarding milk and its thermal treatment before consumption, a recent work has undertaken the metabolomic discrimination between UHT and reconstituted milk . Also, pasteurized milk has been the object of another study in which the search for biomarkers to predict the shelf-life of the milk subjected to such treatment was the aim …”

“…Regarding milk and its thermal treatment before consumption, a recent work has undertaken the metabolomic discrimination between UHT and reconstituted milk. 9 Also, pasteurized milk has been the object of another study in which the search for biomarkers to predict the shelflife of the milk subjected to such treatment was the aim. 10 Although milk is a very heat-stable system in comparison to other food materials, the applied treatment affects not only microorganisms but also milk components.…”