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Omics is used as an analytical tool to investigate wine authenticity issues. Aging authentication ensures that the wine has undergone the necessary maturation and developed its desired organoleptic characteristics. Considering that aged wines constitute valuable commodities, the development of advanced omics techniques that guarantee aging authenticity and prevent fraud is essential. Α solid phase microextraction Arrow method combined with comprehensive two-dimensional gas chromatography-mass spectrometry was developed to identify volatiles in red wines and investigate how aging affects their volatile fingerprint. The method was optimized by examining the critical parameters that affect the solid phase microextraction Arrow extraction (stirring rate, extraction time) process. Under optimized conditions, extraction took place within 45 min under stirring at 1000 rpm. In all, 24 monovarietal red wine samples belonging to the Xinomavro variety from Naoussa (Imathia regional unit of Macedonia, Greece) produced during four different vintage years (1998, 2005, 2008 and 2015) were analyzed. Overall, 237 volatile compounds were tentatively identified and were treated with chemometric tools. Four major groups, one for each vintage year were revealed using the Hierarchical Clustering Analysis. The first two Principal Components of Principal Component Analysis explained 86.1% of the total variance, showing appropriate grouping of the wine samples produced in the same crop year. A two-way orthogonal partial least square – discriminant analysis model was developed and successfully classified all the samples to the proper class according to the vintage age, establishing 17 volatile markers as the most important features responsible for the classification, with an explained total variance of 88.5%. The developed prediction model was validated and the analyzed samples were classified with 100% accuracy according to the vintage age, based on their volatile fingerprint. The developed methodology in combination with chemometric techniques allows to trace back and confirm the vintage year, and is proposed as a novel authenticity tool which opens completely new and hitherto unexplored possibilities for wine authenticity testing and confirmation. [Display omitted] • Optimized SPME-Arrow method combined with GC × GC-MS for wine aging testing. • Tentative identification of 237 volatile compounds. • Establishment of 17 volatile markers responsible for the classification. • Sample classification with 100% accuracy according to the vintage age. [ABSTRACT FROM AUTHOR]

Abstract: The Cretan School of iconography is the last great flowering of the traditional Byzantine painting manner, which is however influenced by different schools and western art. Despite their historical significance, icons of the Cretan School have been rarely studied through modern chemical techniques and therefore very few information is available on the materials used by the Cretan painters. In the present investigation, the organic materials contained in several icons of the Cretan School of Iconography from the collection of the Benaki Museum, Athens, Greece, are analyzed and identified by High Performance Liquid Chromatography coupled to a Diode Array Detector (HPLC–DAD) and Gas Chromatography with Mass Spectrometry (GC–MS). The HPLC–DAD results provide support to a recently published report which showed that kermes used in “Cretan” icons of 15th century and early 16th century was replaced by cochineal which was used in icons dated after early 16th century. This trend is known for western art and it is now proved for Cretan icons, showing thus the influence of the Cretan painters by other European painting schools. Other dyes detected in the historical samples, extracted from Cretan icons are madder (possibly Rubia tinctorum L., according to HPLC profiles) and indigoid dyes. Oils, such as linseed and walnut oil, are identified in samples extracted from the seven icons tested by GC–MS. Egg yolk is identified in the extract of only one icon and animal glue, originated most likely from the gesso ground, is found in six samples. Other organic materials detected by GC–MS were wax, as well as synthetic resins, applied during conservation treatments. [ABSTRACT FROM AUTHOR]