title: Targeted and non-targeted detection of lemon juice adulteration by LC-MS and chemometrics.
abstract: Economically motivated adulteration (EMA) of lemon juice was detected by LC-MS and principal component analysis (PCA). Twenty-two batches of freshly squeezed lemon juice were adulterated by adding an aqueous solution containing 5% citric acid and 6% sucrose to pure lemon juice to obtain 30%, 60% and 100% lemon juice samples. Their total titratable acidities, °Brix and pH values were measured, and then all the lemon juice samples were subject to LC-MS analysis. Concentrations of hesperidin and eriocitrin, major phenolic components of lemon juice, were quantified. The PCA score plots for LC-MS datasets were used to preview the classification of pure and adulterated lemon juice samples. Results showed a large inherent variability in the chemical properties among 22 batches of 100% lemon juice samples. Measurement or quantitation of one or several chemical properties (targeted detection) was not effective in detecting lemon juice adulteration. However, by using the LC-MS datasets, including both chromatographic and mass spectrometric information, 100% lemon juice samples were successfully differentiated from adulterated samples containing 30% lemon juice in the PCA score plot. LC-MS coupled with chemometric analysis can be a complement to existing methods for detecting juice adulteration.
authors.affiliation: a Center for Food Safety and Applied Nutrition, Division of Food Processing Science and Technology , US Food and Drug Administration (USFDA) , Bedford Park , IL , USA.
authors.forename: Zhengfang
authors.initials: Z
authors.lastname: Wang
authors.affiliation: a Center for Food Safety and Applied Nutrition, Division of Food Processing Science and Technology , US Food and Drug Administration (USFDA) , Bedford Park , IL , USA.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Jablonski
mesh_terms: D001628:Beverages / Q000032:analysis*; D002853:Chromatography, Liquid; D002957:Citrus / Q000737:chemistry*; D005506:Food Contamination / Q000032:analysis; D013058:Mass Spectrometry
keywords: LC-MS; Lemon juice; Orbitrap; adulteration; chemometrics; principal component analysis