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1.
Food Chem ; 219: 33-39, 2017 Mar 15.
Article in English | MEDLINE | ID: mdl-27765235

ABSTRACT

The quality and genuineness of extra-virgin olive oils (EVOOs) were assessed following the methods and parameters of EU Commission Regulation N° 2568/91/EEC and subsequent modifications, which also set specific limits for fatty-acid ethyl esters (FAEEs). This study included a subset of EVOOs from among 399 samples analysed as part of a monitoring study for FAEEs in EVOOs. The subset was subjected to statistical evaluation to quantify the relationships between FAEE content and sensory defects associated with fermentation: fusty/muddy sediment, musty/humid/earthy, and winey/vinegary. The use of multiple regression analysis demonstrates that FAEE content can be inferred as a function of the intensity of organoleptic defects for samples with high alkyl esters content. The intensity of the rancid defect negatively influences the accuracy of this model, because of underestimation of the fermentation defects that are also present.


Subject(s)
Esters/analysis , Fatty Acids/analysis , Olive Oil/chemistry , Plant Oils/analysis , Sensation/physiology , Fermentation
2.
Food Chem ; 196: 98-105, 2016 Apr 01.
Article in English | MEDLINE | ID: mdl-26593470

ABSTRACT

Isotope Ratio Mass Spectrometry (IRMS), (1)H Nuclear Magnetic Resonance ((1)H NMR), conventional chemical analysis and chemometric elaboration were used to assess quality and to define and confirm the geographical origin of 177 Italian PDO (Protected Denomination of Origin) olive oils and 86 samples imported from Tunisia. Italian olive oils were richer in squalene and unsaturated fatty acids, whereas Tunisian olive oils showed higher δ(18)O, δ(2)H, linoleic acid, saturated fatty acids ß-sitosterol, sn-1 and 3 diglyceride values. Furthermore, all the Tunisian samples imported were of poor quality, with a K232 and/or acidity values above the limits established for extra virgin olive oils. By combining isotopic composition with (1)H NMR data using a multivariate statistical approach, a statistical model able to discriminate olive oil from Italy and those imported from Tunisia was obtained, with an optimal differentiation ability arriving at around 98%.


Subject(s)
Magnetic Resonance Spectroscopy/methods , Olive Oil/chemistry , Plant Oils/chemistry , Italy , Mass Spectrometry/methods , Tunisia
3.
J Mass Spectrom ; 49(9): 840-9, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25230181

ABSTRACT

European Regulation (EEC) 2568/91 has been setting the minimum requirements in order to allow labeling of oil as extra virgin. These general requirements, are based on physical-chemical and organoleptic parameters directly linked to the freshness and quality of the product. Isotope ratio mass spectrometry (IRMS) was demonstrated to be a useful tool for the discrimination of the origin of unknown samples, because the obtained data are practically independent of the cultivar employed and the production technique. In this work, the evaluation of the composition of fatty acid methyl esters (FAME) alongside with the determination of stable isotope ratio of C in bulk oils and in main FAME constituents have been investigated as a tool to improve geographical discrimination of Italian Protected Designation of Origin/Protected Geographical Indication (PDO/PGI) samples. For this purpose, authentic PDO/PGI extra virgin olive oils were sampled at oil mills and grouped into different sets according to their areas of provenience. The use of principal component analysis and partial least squares discriminant analysis multivariate analysis techniques demonstrated that discrimination of olive oil samples can be done using geographical and pedoclimatic parameters predominantly by using δ(13) C results of bulk and individual fatty acids. Results showed that δ(13) C values are a more reliable marker of origin with respect to fatty acid composition.


Subject(s)
Fatty Acids/analysis , Fatty Acids/chemistry , Mass Spectrometry/methods , Plant Oils/analysis , Plant Oils/chemistry , Biomarkers/analysis , Carbon Isotopes/analysis , Discriminant Analysis , Least-Squares Analysis , Olive Oil
4.
Article in English | MEDLINE | ID: mdl-22959825

ABSTRACT

The incorrect use of preservatives in cheeses may compromise food safety and damage consumers. According to the law, more than one preservative may be contemporarily used in cheeses. So a method for their contemporary detection may be useful for both manufacturers and control agencies quality control. In this research a liquid chromatography-tandem mass spectrometric with electrospray ionization method for the multi-determination of seven preservatives (benzoic acid, citric acid, hexamethylenetetramine, lysozyme, natamycin, nisin and sorbic acid) in cheese was developed. The preservatives were contemporarily extracted from cheese by a single procedure, and analyzed by RP-LC/ESI-MS/MS (Ion Trap) in positive ionization mode, with single reaction monitoring (SRM) acquisition. Three sample types (hard, pasta filata and fresh cheese) were used for method evaluation. Recoveries were mostly higher than 90%; MDLs ranged from 0.02 to 0.26 mgkg(-1), and MQLs were included between 0.07 and 0.88 mgkg(-1). Due to matrix effect, quantitation was performed by referring to a matrix matched calibration curve, for each cheese typology. This method was also applied to commercial cheese samples, with good results. It appears fast, reliable and suitable for both screening and confirmation of the presence and quantitation of the preservatives in a single, multi-detection analysis.


Subject(s)
Cheese/analysis , Chromatography, High Pressure Liquid/methods , Food Preservatives/analysis , Tandem Mass Spectrometry/methods , Chromatography, Reverse-Phase/methods , Italy , Limit of Detection , Linear Models , Reproducibility of Results
5.
Rapid Commun Mass Spectrom ; 24(6): 705-13, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20169561

ABSTRACT

A common fraud in the dairy field is the addition of sheep's milk to goat's cheeses, because it has a very similar taste to goat's milk, but is more available, and is commonly considered to have a better capacity to curdle. For similar reasons, and due to economic convenience, sheep's cheeses may also contain fraudulent cow's milk. In order to detect this fraud, an EU official method may be used, but it is only a qualitative method (presence/absence of cow's milk). A method able to quantify the presence of sheep's milk during cheese production in goat's and cow's cheeses was developed. The method is based on liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) analysis of peptides of a casein extract from the cheese. By a simple procedure, caseins are extracted from cheeses, solubilized, digested with plasmin, and subsequently analyzed by LC/ESI-MS/MS. A typical sheep's peptide produced by plasmin hydrolysis (m/z = 860) was accurately selected and analyzed to understand if, and by how much, a declared pure goat's cheese contains sheep's milk. By analyzing the same peptide it is also possible to detect if, and by how much, a declared pure sheep's milk contains, or not, cow's milk. The method was applied to several goat's and cow's cheese samples. Quantitation was performed with a calibration curve obtained by analyzing curd cheeses containing different percentages of sheep's milk. The method detection limit and method quantitation limit were evaluated. This method appears accurate and suitable for detecting up to 2% of sheep's milk in cheeses.


Subject(s)
Caseins/analysis , Cheese/analysis , Milk/chemistry , Peptide Fragments/chemistry , Proteomics/methods , Tandem Mass Spectrometry/methods , Animals , Calibration , Caseins/metabolism , Cattle , Chromatography, Liquid/methods , Fibrinolysin/metabolism , Goats , Linear Models , Peptide Fragments/metabolism , Reproducibility of Results , Sensitivity and Specificity , Spectrometry, Mass, Electrospray Ionization/methods
6.
Talanta ; 72(2): 419-26, 2007 Apr 30.
Article in English | MEDLINE | ID: mdl-19071634

ABSTRACT

A solid phase extraction-high performance liquid chromatography-tandem mass spectrometry based analytical method suitable for simultaneous analysis of benzidine, 3,3'-dichlorobenzidine, mono-, di-, and tri-chloroanilines has been developed. Normal phase separation by liquid chromatography was performed using a cyano propyl methyl silica column, and atmospheric pressure photoionization was employed as interface with mass spectrometer. The developed method was evaluated in terms of limit of detection, accuracy, and precision. The quantification limit for all the compounds ranged between 7 and 112ngL(-1), while recovery for all the compounds was higher than 94%. The method was tested by analyzing different industrial wastes, showing residual contamination by most of the analytes.

7.
J Agric Food Chem ; 53(14): 5518-25, 2005 Jul 13.
Article in English | MEDLINE | ID: mdl-15998108

ABSTRACT

An automated on-line solid-phase extraction-liquid chromatography-electrospray tandem mass spectrometry (SPE-LC-ESI-MS/MS) method was developed for the determination of ochratoxin A (OTA) in alcoholic beverages. Mean recoveries for wine and beer were, respectively, 75 and 82%. Detection was achieved in negative ionization with a Q TRAP mass spectrometer operating in multiple-reaction monitoring (MRM) mode or enhanced product ion (EPI) mode, using the third quadrupole as linear ion trap. The MRM mode turned out to be more sensitive; the method allowed accurate determination of OTA in the range of 0.01-25 ng mL(-1) using external calibration. Within-day and between-day relative standard deviation percentages were <6.2 and <9.1%, respectively. In EPI mode, fragmentation spectra at the limit of quantification (0.03 ng mL(-1)) and good linearity could be obtained. Application of the method (MRM mode) to the analysis of several wine and beer samples purchased in local stores revealed OTA levels in the ranges of 0.03-1.44 ng mL(-1) for wines and 0.02-0.14 ng mL(-1) for beers.


Subject(s)
Autoanalysis/methods , Beer/analysis , Chromatography, Liquid/methods , Ochratoxins/analysis , Spectrometry, Mass, Electrospray Ionization/methods , Wine/analysis , Food Contamination/analysis , Mycotoxins/analysis
8.
Talanta ; 66(4): 1025-33, 2005 May 15.
Article in English | MEDLINE | ID: mdl-18970087

ABSTRACT

Phytoestrogens are diphenolic compounds that are present in several edible plants and are particularly abundant in soybeans. Because of their estrogenical, antriestrogenical, anticarcinogenic and antioxidant activities in animal and humans, they became of great interest. Dietary factors are considered important in determination of risks, in fact, studies have revealed beneficial or protective effects of the consumption of vegetables, in particular soy and soybean products. So that in the present paper the simultaneous determination of eight isoflavones and coumestrol in vegetables is reported. The quantitative analysis has been made by means of LC separation combined with tandem mass spectrometry. In particular, a new simple and fast extraction methodology and a clean-up, based on cold aided de-fatting, is proposed. Method performance was evaluated by comparison with a reference procedure. The developed procedure was then used for a survey of phytoestrogens concentration in some selected vegetables.

9.
Rapid Commun Mass Spectrom ; 19(2): 275-82, 2005.
Article in English | MEDLINE | ID: mdl-15609370

ABSTRACT

A sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for determining the type B fumonisin mycotoxins in corn-based foodstuffs is described. Fumonisins FB1 and FB2 were extracted from a 1 g sample by homogenization with acetonitrile/water (75:25, v/v, 50 mmol/L formic acid, 25 mL final volume) and the extract was defatted on C18 phase. Volumes of 5 mL of crude extracts were cleaned up on Carbograph-4 cartridges. The final solution was analyzed by HPLC with electrospray ionization mass spectrometry in positive ion mode using multiple reaction monitoring with a QqQ linear ion trap mass spectrometer. Recoveries for spiked corn-based foodstuffs ranged from 91-105% (RSD% < or =8%), and method detection limits were < or =2 ng/g for FB1 and < or =1 ng/g for FB2. Two different spiking levels were tested (5000 and 100 ng/g for FB1, 1000 and 20 ng/g for FB2). Quantitation was achieved by an external calibration procedure using matrix-matched standards, with diclofenac added post-cleanup as internal standard for the LC/MS/MS analyses. Calibration curves showed linearity in the concentration range 0.005-5 ng/microL of final extract (0.992 < or = R2< or =0.995). Two other fumonisins, FB3 and FB4, were identified in naturally contaminated samples of corn meal using an information-dependent acquisition protocol that looped three experiments, including neutral loss scan, enhanced resolution scan, and enhanced product ion scan. FB3 and FB4 quantitation was estimated as peak area ratios relative to the FB2 response in view of the lack of both standards. This work also includes an application of the present LC/MS/MS method to some maize and maize-based product samples (corn meal, cornflakes and popcorn) collected from Italian stores. FB1 and FB2 contamination levels exceeding the European Union recommendation were found in 8 out of 15 corn meal samples.


Subject(s)
Chromatography, High Pressure Liquid/methods , Food Microbiology , Food Supply , Fumonisins/analysis , Spectrometry, Mass, Electrospray Ionization/methods , Zea mays/chemistry , Italy , Reproducibility of Results , Sensitivity and Specificity , Spectrometry, Mass, Electrospray Ionization/instrumentation , Zea mays/microbiology
10.
J AOAC Int ; 86(4): 729-36, 2003.
Article in English | MEDLINE | ID: mdl-14509432

ABSTRACT

A new method based on matrix solid-phase dispersion (MSPD) on-line with a solid-phase extraction (SPE) cleanup process followed by liquid chromatography with tandem mass spectrometry (LC/MS/MS) is presented for the determination of 3 macrocyclic lactone mycotoxins in fish tissues: zearalenone, alpha-zearalenol, and beta-zearalenol. The sample was prepared in a device that used a reversed-phase material (C18) or a normal-phase material (neutral alumina) as a matrix dispersing agent, and a graphitized carbon black cartridge was used for sequential cleanup by SPE. LC/MS/MS was used for selective determination. Isocratic elution with acetonitrile-methanol-water was used for LC separation; for MS/MS, 2 types of interfaces (a pneumatically assisted electrospray ionization interface or an atmospheric pressure chemical ionization interface) were evaluated and compared in terms of the intensity of the total ion current produced by each analyte. The use of highly selective MSPD on-line with SPE for sample preparation before analysis allowed the removal of interfering matrix compounds present in tissue extracts that would otherwise cause severe ionization suppression of zearalenone and its metabolites during the ionization process. Average recoveries at 100 ng/g were between 83 and 103% with C18 and > or = 67% with neutral alumina; the relative standard deviations were < 11% with C18 and < 18% with alumina. The limits of detection ranged from 0.1 to 1.0 ng/g. Sample preparation is simple to perform, no special technical equipment is required, and solvent volumes are minimal.


Subject(s)
Chromatography, Liquid/methods , Mass Spectrometry/methods , Meat/analysis , Mycotoxins/analysis , Oncorhynchus mykiss , Zearalenone/analysis , Zeranol/analogs & derivatives , Animals , Liver/chemistry , Quality Control , Sensitivity and Specificity , Zeranol/analysis
11.
Rapid Commun Mass Spectrom ; 17(10): 1037-43, 2003.
Article in English | MEDLINE | ID: mdl-12720283

ABSTRACT

A reliable, sensitive and selective liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed to determine four trichothecene mycotoxins (nivalenol, deoxynivalenol, fusarenon X and 3-acetyldeoxynivalenol) in maize. Sample preparation was performed by extracting the analytes with a mixture of acetonitrile and water, followed by a solid-phase extraction with Carbograph-4 cartridges as the purification step. For the LC/MS/MS analysis two interfacing systems, Turbo IonSpray (TISP) and atmospheric pressure chemical ionization (APCI), were compared in both negative and positive ion modes. LC and MS parameters were optimized to achieve better results and sensitivity. The effect of mobile phase modifiers such as ammonium acetate and formic acid on the ionization yield was also evaluated. The best results were obtained using the electrospray ionization (ESI) interface in negative ion mode and the multiple reaction monitoring mode (MRM) for the quantitation. The detection limits ranged between 10 ng/g for fusarenon X and 1.5 ng/g for deoxynivalenol. A linear working range was achieved with a standard deviation between 3 and 10% and recovery rates from the maize samples above 81%. The procedure was applied to the analysis of a set of maize samples collected from farms located in different areas of northern and central Italy. The investigated samples turned out to be contaminated primarily with deoxynivalenol and, to a minor extent, with its derivatives.


Subject(s)
Mycotoxins/analysis , Trichothecenes/analysis , Zea mays/chemistry , Chromatography, High Pressure Liquid , Indicators and Reagents , Mass Spectrometry , Reproducibility of Results , Solvents
12.
Rapid Commun Mass Spectrom ; 16(2): 134-41, 2002.
Article in English | MEDLINE | ID: mdl-11754259

ABSTRACT

An evaluation was made of the feasibility of using reversed-phase liquid chromatography/tandem mass spectrometry with an electrospray interface (LC/ESI-MS/MS) to measure traces of phenoxyacid herbicides and their metabolites in surface and drinking water samples. The procedure involved passing 0.5 L of river and drinking water samples through a 0.5 g graphitized carbon black (GCB) extraction cartridge. Recovery was higher than 85% irrespective of the aqueous matrix in which the analytes were dissolved. A conventional 4.6-mm i.d. reversed-phase LC C-18 column operating with a mobile phase flow rate of 1 mL/min was used to chromatograph the analytes. A flow of 200 microL/min of the column effluent was diverted to the ESI source. The limits of detection (signal-to-noise ratio = 3) of the method for the pesticides considered in drinking and surface water samples are less than 0.1 ng/L for phenoxyacid herbicides, and about 5-10 ng/L for their metabolites (2,4-dichlorophenol and 4-chloro-2-methylphenol).


Subject(s)
2,4-Dichlorophenoxyacetic Acid/analogs & derivatives , 2-Methyl-4-chlorophenoxyacetic Acid/analogs & derivatives , Herbicides/analysis , Phenols/analysis , Proline/analogs & derivatives , Water Pollutants/analysis , Water/analysis , 2,4-Dichlorophenoxyacetic Acid/analysis , 2-Methyl-4-chlorophenoxyacetic Acid/analysis , Butyrates/analysis , Chromatography, High Pressure Liquid/methods , Proline/analysis , Pyridines/analysis , Quality Control , Sensitivity and Specificity , Spectrometry, Mass, Electrospray Ionization/methods
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