Polyphenols are a diverse group of compounds possessing various health-promoting properties that are of utmost importance for many wine sensory attributes. Apart from genetic and environmental parameters, the implementation of specific oenological practices as well as the subsequent storage conditions deeply affect the content and nature of the polyphenols present in wine. However, polyphenols are effectively employed in authenticity studies. Provision of authentic wines to the market has always been a prerequisite meaning that the declarations on the wine label should mirror the composition and provenance of this intriguing product. Nonetheless, multiple cases of intentional or unintentional wine mislabeling have been recorded alarming wine consumers who demand for strict controls safeguarding wine authenticity. The emergence of novel platforms employing instrumentation of exceptional selectivity and sensitivity along with the use of advanced chemometrics such as NMR (nuclear magnetic resonance)- and MS (mass spectrometry)-based metabolomics is considered as a powerful asset towards wine authentication.

Wine metabolomics constitutes a powerful discipline towards wine authenticity assessment through the simultaneous exploration of multiple classes of compounds in the wine matrix. Over the last decades, wines from autochthonous Greek grape varieties have become increasingly popular among wine connoisseurs, attracting great interest for their authentication and chemical characterization. In this work, 46 red wine samples from Agiorgitiko and Xinomavro grape varieties were collected from wineries in two important winemaking regions of Greece during two consecutive vintages and analyzed using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QToF-MS). A targeted metabolomics methodology was developed, including the determination and quantification of 28 phenolic compounds from different classes (hydroxycinnamic acids, hydroxybenzoic acids, stilbenes and flavonoids). Moreover, 86 compounds were detected and tentatively identified via a robust suspect screening workflow using an in-house database of 420 wine related compounds. Supervised chemometric techniques were employed to build an accurate and robust model to discriminate between two varieties.

This study evaluated the antioxidant capacity, total phenol content, and sensory profile of selected Greek wines made from Vitis vinifera L. c.v. Moschofilero in two consecutive vintages, treated with powdered Hippophae rhamnoides L. leaves (HRL). Radical Scavenging activity, reducing power, total phenol content (TPC), and color intensity increased in a linear manner in relation to HRL treatments. Indicatively the addition of 0.8 g/L of HRL increased the radical scavenging activity as determined via the inhibition of the 2,2-diphenyl-1- picrylhydrazyl (DPPH) radical from 28.4 to 55.8% in comparison to the initial values. Equally the reducing power as determined by the ferric reducing antioxidant power (FRAP) assay increased from 35.3 to 62.1%, and total phenol content values increased from 11% to 23.7% and the color intensity increased from 39.9 to 50.7%. The main oenological attributes examined, remained unchanged after the HRL addition. The addition of up to 0.4 g/L of HRL did not have a major impact on the organoleptic characteristics of the wines tasted whereas concentrations higher than 0.8 g/L were not considered beneficial. Results denote that the addition of H. rhamnoides leaves to white wines contributes positively to the overall antioxidant capacity and could be used if authorized as an antioxidant agent in wines vinified in the absence of or in synergy with sulphur dioxide.

Wine quality and safety is affected by the food contact materials (FCMs) used. These materials are expected to protect the beverage from any chemical, physical, or biological hazard and preserve its composition stable throughout its shelf-life. However, the migration of chemical substances from FCMs is a known phenomenon and requires monitoring. This review distinguishes the migrating chemical substances to those of (i) industrial origin with potential safety effects and those of (ii) natural occurrence, principally in cork (ex. tannins) with organoleptic quality effects. The review focuses on the migration of industrial chemical contaminants. Migration testing has been applied only for cork stoppers and tops, while other materials like polyethylene terephthalate (PET) bottles with aluminum cups, paperboard cartons, stainless steel vats, and oak casks have been examined for the presence of chemical migrating substances only by wine analysis without migration testing. The dominant analytical techniques applied are gas and liquid chromatography coupled to mass spectrometry (MS) for the determination of organic compounds and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and ICP-MS for elemental analysis. Targeted approaches are mostly applied, while limited non-target methodologies are reported. The identified migrating substances include authorized substances like phthalate plasticizers, monomers (bisphenol A), antioxidants (Irganox 1010), known but non-authorized substances (butylparaben), break-down products, oxidation products (nonylphenol), polyurethane adhesive by-products, oligomers, ink photoinitiators, and inorganic elements. A preliminary investigation of microplastics’ migration has also been reported. It is proposed that further research on the development of comprehensive workflows of target, suspect, and non-target analysis is required to shed more light on the chemical world of migration for the implementation of an efficient risk assessment and management of wine contact materials.

This study evaluated the influence of the addition of increasing quantities of Hippophae rhamnoides L. leaves (HRL) on the radical scavenging activity, main oenological parameters and organoleptic characteristics of three white wines made from moschofilero and one white wine made from riesling grapes respectively. Radical Scavenging activity, reducing power, total phenol content (TPC) and color intensity increased in a linear manner in relation to HRL treatments. Indicatively the addition of 0.8 g/L of HRL increased the radical scavenging activity as determined via the inhibition of the DPPH radical from 23.2 to 58.4% in comparison to the initial values. Equally the reducing power as determined by the FRAP assay increased from 34.5 to 82.3%, TPC increased from 12.3 to 26.8% and the color intensity increased from 39-50% . The main oenological attributes examined, remained unchanged after the HRL addition. The addition of up to 0.4 g/L of HRL did not have a major impact on the organoleptic characteristics of the wines tasted whereas concentrations higher than 0.8 g/L were not considered beneficial. Results denote that the addition of Hippophae rhamnoides L. leaves to white wines contributes positively to the overall antioxidant capacity and could be used as an antioxidant agent in wines vinified in the absence of sulphur dioxide.