Greek Graviera Cheese Assessment through Elemental Metabolomics—Implications for Authentication, Safety and Nutrition

Abstract

This study presents the comprehensive elemental profile of Greek Graviera (Gruyère) cheeses. In total, 105 samples from nine different geographic regions produced from sheep, goat and cow milk and their mixtures were assessed. Elemental signatures of 61 elements were investigated for determination of geographic origin and milk type. Regional and milk type classification through Linear Discriminant Analysis was successful for almost all cases, while a less optimistic cross validation exercise presented lower classification rates. That points to further research using a much larger sample set, increasing confidence for cheese authentication utilizing also bioinformatics tools under development. This is the first study reporting signatures of 61 elements in dairy products including all sixteen rare earth elements and all seven precious metals. Safety and quality were assessed regarding toxic and nutritive elements. According to both EU and USA regulations and directives, Graviera is a nutritional source for trace and macro elements with low levels of toxic elements.

Physicochemical, Spectroscopic, and Chromatographic Analyses in Combination with Chemometrics for the Discrimination of the Geographical Origin of Greek Graviera Cheeses

“…Results of the present study regarding mineral content are in general agreement with those of Gonzalez-Martin et al [ 29 ] who determined the mineral content of cow, sheep and goat milk from Zamora, Spain. Danezis et al [ 25 ] reported the signature of 61 elements in Greek graviera cheeses including all sixteen rare earth elements and all seven precious metals which were used to differentiate cheese geographical origin. Likewise, Vatavali et al [ 26 ] determined among other analytical parameters, a similar profile of minerals for graviera cheeses from six different geographical origins in Greece.…”

“…However, the method was not always able to discriminate between PDO and non-PDO buffalo mozzarella originating from the same production area. Recently, Danezis et al [25] determined the elemental profile of 105 graviera cheeses from nine different geographic regions in Greece in an effort to differentiate the cheeses based on geographical origin and milk type. Cheeses were produced from sheep, goat, and cow milk, as well as their mixtures.…”

“…Bontempo et al [24] used stable isotope ratio analysis and elemental analysis in combination with chemometrics to determine the authenticity of Italian PDO cheeses. Finally, Danezis et al [25] used ICP-MS to determine a comprehensive elemental profile of Greek graveria cheeses in an effort to differentiate the cheeses by geographical origin and milk type.…”

Authenticity and Typicity of Traditional Cheeses: A Review on Geographical Origin Authentication Methods

“…For cheese geographical origin authentication, ICP-MS is the preferred choice since it is a rapid, multi-element analysis able to quantify trace (ppm–ppb) or ultra-trace (ppb–ppq) elemental concentrations [ 49 ]. As elemental composition is mainly affected by geological and pedological traits, multiple factors can affect the element content in cheese, such as animal breed, feed vegetation, drinking water, and mineral supplementation [ 49 , 50 ]. Possible effects of cheese-making on cheese elements could derive from the clotting agent, curd acidification, manufacturing equipment, curd washing, and salt washing/brining [ 34 , 51 ].…”

FoodOmicsGR_RI: A Consortium for Comprehensive Molecular Characterisation of Food Products

“…Elemental Metabolomics based on Elemental Mass spectrometry [ 82 ] has been applied for food authentication [ 83 ], as well as determination of geographic, genetic and processing origin. Applications concern the geographical and botanical type of honey [ 84 ], authentication of Greek Protected Designation of Origin cheeses [ 85 ], modulation of egg metallome with flavonoids [ 86 ], authentication, safety and nutrition of Graviera Cheese [ 87 ], and determination of meat production methods (wild vs. farmed) [ 88 ]. Elemental metabolomics applied to PDO “Fava Santorinis” [ 89 ] revealed that rare earth elements’ minimal harvest year variation facilitates robust geographical origin discrimination, while data fusion with trace elements discriminates “Fava Santorinis” from other yellow split peas [ 90 ].…”