Gas Chromatography Coupled with Chemometric Method for Authentication of Romanian Cheese (original) (raw)
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Journal of Agricultural and Food Chemistry, 2016
Cyclopropane fatty acids (CPFA), as lactobacillic acid and dihydrosterculic acid, are components of bacterial membranes and have been recently detected in milk and in dairy products from cows fed with corn silage. In this paper, a specific quantitative GC-MS method for the detection of CPFA in cheeses was developed and the quality parameters of the method (LOD, LOQ, linearity, intralaboratory precision) were assessed. Limit of detection and quantitation of CPFA were respectively 60 and 200 mg/kg of cheese fat, and the intralaboratory precision, determined on three concentration levels, satisfied the Horwitz equation. Method was applied to 304 samples of PDO cheeses of certified origin, comprising Parmigiano Reggiano (Italy), Grana Padano (Italy), Fontina (Italy), Comté (France), Gruyère (Switzerland). Results showed that CPFA were absent in all the cheeses whose Production Specification Rules expressly forbid the use of silages (Parmigiano Reggiano, Fontina, Comté and Gruyère). CPFA were instead present, in variable concentrations (300-830 mg/kg of fat), in all the samples of Grana Padano cheese (silages admitted). Mix of grated Parmigiano Reggiano and Grana Padano were also prepared, showing that the method is able to detect the counterfeiting of Parmigiano Reggiano with other cheeses until 10-20 %. These results comfort the hypothesis that CPFA can be used as a marker of silage feedings for cheeses, and the data reported can be considered a first attempt to create a database for CPFA presence in PDO cheeses.
Journal of Dairy Science, 2005
The traceability of Asiago mountain cheese was established by analyzing samples of herbaceous species, milk, and cheese of mountain origin using the headspace solid-phase microextraction sampling procedure coupled with gas chromatography-mass spectrometry. As preliminary work had highlighted the characteristic presence of sesquiterpenes in Asiago mountain cheese, these species were considered effective markers of mountain origin. Systematic qualitative analysis, carried out using a carboxen/polydimethylsiloxane fiber, revealed several sesquiterpenes in mountain herbage and milk, in particular β-caryophyllene and α-humulene, in Asiago mountain cheese, confirming sesquiterpenes as markers of cheese produced from animals grazing on mountain pastures. Analysis was performed on 19 samples of herbage, 8 of milk, and 8 of cheese, collected in summer from 4 mountain farms on the Asiago plateau. For quantitative analysis of caryophyllene in cheese, polydimethylsiloxane fiber sampling, coupled with the standard addition method to eliminate matrix effect, was preferred. The amount of β-caryophyllene found ranged from 21 to 65 g/kg.
Journal of Dairy Science, 2014
The objective of this study was to determine the gross composition, proteolysis, and volatile and texture profiles during ripening of industrial (IND) and traditional (TRD) Beaten (Bieno sirenje) cheeses made by using ewe milk. In the course of the analyses, statistical differences were determined in some physicochemical parameters, nitrogen fractions, and total free amino acid levels between TRD and IND types of cheese. Higher levels of proteolysis were observed in IND cheeses than in TRD cheeses during ripening. Levels of residual β-and α s -caseins were 72.2 and 48.7%, respectively, in 180-d-old TRD cheeses. However, the residual levels were 52.8% for β-casein and 18% for α s -casein in IND cheeses. Similar differences were noted for the reversedphase HPLC peptide profiles of 2 types of cheeses. Also, higher concentrations of peptides were eluted in IND cheeses than in TRD cheeses during ripening. A total of 73 volatile compounds, including alcohols (16), esters (17), acids (14), terpenes (7), ketones (5), aldehydes (4), and miscellaneous (10) were identified. The IND cheeses contained higher levels of carboxylic acids, esters, alcohols, and terpenes than the TRD cheeses; however, the same levels of methyl ketones were determined in the 2 types of cheeses at the end of ripening. These may be due to some differences (e.g., pasteurization and scalding temperature, among other factors) in the manufacture of the 2 types of Beaten cheeses. The textural profile of Beaten cheeses showed that TRD production method resulted in firmer, less fracturable, and stiffer cheeses than the IND production method. In conclusion, the results suggest that the use of industrial production method (pasteurization of cheese milk and curd scalding at 70°C) in the manufacture of Beaten ewe milk cheese enriched the volatile profile of the cheese.
Food Research International, 2018
The present study sought to develop a headspace solid-phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS) method to quantify free fatty acids (FFAs) and hexanal in cheese, and to track theirs levels over time. The developed method was applied on Fresh Asiago and Grana Padano cheeses, and FFAs and hexanal levels were monitored over 4 and 12 weeks respectively. Their evolutions were also compared from two types of packaging films: a high-density polyethylene (HDPE) package and a packaging bag named Ideabrill®. The later allowed a lower increase of these analytes (11.6-fold increase for Grana Padano and 5.9 for Fresh Asiago) compared to the HDPE packaging (21.5-fold increase for Grana Padano and 7.4 for Fresh Asiago). This method can
Journal of dairy science, 2013
We proposed an application methodology that combines metabolic profiling with multiple appropriate multivariate analyses and verified it on the industrial scale of the ripening process of Cheddar cheese to make practical use of hydrophilic low-molecular-weight compound profiling using gas chromatography-mass spectrometry to design optimal conditions and quality monitoring of the cheese ripening process. Principal components analysis provided an overview of the effect of sodium chloride content and kind of lactic acid bacteria starter on the metabolic profile in the ripening process of Cheddar cheese and orthogonal partial least squares-discriminant analysis unveiled the difference in characteristic metabolites. When the sodium chloride contents were different (1.6 and 0.2%) but the same lactic acid bacteria starter was used, the 2 cheeses were classified by orthogonal partial least squares-discriminant analysis from their metabolic profiles, but were not given perfect discrimination...
Journal of Dairy Science, 2004
The study of the headspace components of fresh smoked goat cheese, was carried out by means of solidphase microextraction using a polyacrylate fiber followed by gas chromatography/mass spectrometry. The samples studied were six artisan Palmero cheeses manufactured following traditional methods and smoked using pine needles. The cheese regions studied were exterior, interior, and a cross section. In total, more than 320 components were detected, the exterior region being the richest in components, among which were acids, alcohols, esters, hydrocarbons, aldehydes, ketones, furan and pyran derivatives, terpenes and sesquiterpenes, nitrogen derivatives, phenol, guaiacol and syringol derivatives, ethers, and others. In addition to typical cheese components, typical smoke components were also detected; these latter were present especially in the headspace of the exterior region and only those in significant concentrations in the exterior region were also detected in the interior. The main components were acids and phenolic derivatives. These latter compounds play an important role in the flavor of this cheese, and their relative proportions together with the presence of specific smoke components derived from pine leaves may be considered of interest in order to distinguish this cheese from others smoked with different vegetable matter.
2010
Fossa cheese is an Italian hard cheese, ripened for up to 3 months in underground pits dug into tuffaceous rock. During this period, the cheese develops a unique flavour and intense and somewhat piquant aroma. Solid-phase microextraction gas chromatography/mass spectrometry (SPME-GC/MS) was utilized to characterize the volatile organic compounds (VOCs) of Fossa cheese. A total of 75 VOCs were separated and identified; in particular, the major class of compounds found in the cheeses ripened in the pits were the esters of fatty acids. Discriminant analysis of volatile profiles allowed us to distinguish between cheeses in different stages of seasoning (60-day-old cheese and cheese ripened an additional 90 days in and out of the pits).
Cheeses are characterized by several chemical-physical properties that make it difficult for the microorganisms growth, consequently. The actual European legislation allows the addition of few food additives in this type of food products. In this work, the entire procedure of extraction, purification, chromatographic separations and quali/quantitative determination of seven food additives (sorbic acid, benzoic acid, lactic acid, acetic acid, nitrites, nitrates and phosphates) was developed and applied for the analysis of different types of cheese (mozzarella, cheese spread, semi-hard and hard cheeses). Through validation procedure it was possible to evaluate the most important validation parameters. Extended calibration curves (r > 0.990) were obtained for all the analyzed compounds. Recovery values ranged from 72.8% to 98.4% and a good repeatability was obtained, with precision levels in the range of 0.03% -0.11% (n = 6). The potential and feasibility of the method were tested by analysing real samples, such as mozzarella, cheese spread, semi-hard and hard cheeses, confirming that the method is well suited to satisfy the demands for accurate confirmation analyses of seven food additives in cheeses, which is especially valuable in official check analyses and in monitoring schemes.
Journal of the Serbian Chemical Society, 2014
In this study, the volatile profiles of a type of economically important cheeses for the FYR Macedonian dairy sector were characterized. A total of eighteen samples belonged to 6 different geographical regions of Beaten cheese, including cheeses from Kumanovo, Tetovo, Struga, Resen, Veles and Radovish were comparatively studied for their volatile profiles. Sixty two volatile compounds were identified in the cheeses by solid-phase microextraction combined with gas chromatography-mass spectrometry and the results are discussed based on their chemical classes (18 esters, 13 ketones, 10 acids, 8 alcohols, 5 terpenes, and 8 miscellaneous compounds). Acids, esters and alcohols were the most abundant classes identified and were highly dependent on the geographical origin of cheeses. Beaten cheese from Struga had the highest levels of carboxylic acids, ketones, alcohols, esters and terpenes. The Beaten cheese from other geographical origin had low levels of volatiles probably from the effect of variable characteristics of used milk and different cheese making process which affects the biochemical processes.
Journal of Agricultural and Food Chemistry, 2004
The stable isotope ratios (δ 13 C, δ 15 N, and δ 34 S of casein and δ 13 C and δ 18 O of glycerol) measured by IRMS of French, Italian, and Spanish cheeses are presented and discussed. Variability factors such as animal-feeding regimen, geographical origin, and climatic and seasonal conditions were studied to check the possibilities of cheese characterization offered by each isotopic parameter. δ 13 C values of both casein and glycerol appeared to be strongly correlated to the amount of maize in the animal diet. δ 15 N and δ 34 S of casein proved to be mostly influenced by the geoclimatic conditions of the area (aridity, closeness to the sea, altitude). δ 18 O of glycerol was more dependent on the geographical origin of the cheeses and on climatic/seasonal parameters. By applying a multivariate stepwise canonical discriminant analysis, good discrimination possibilities for the different European cheeses were obtained, confirmed by the classification analysis, when >90% of the samples were correctly reclassified.