Simona Sighinolfi

Geographical traceability based on 87Sr/86Sr indicator: a first approach for PDO Lambrusco wines from Modena.

The main goal of this study was to evaluate (87)Sr/(86)Sr ratio in different matrices, namely soils, branches, and grape juices, of an oenological food chain in order to develop a robust analytical strategy able to link the investigated food to its territory of origin. The (87)Sr/(86)Sr has been used as traceability marker and several aspects, affected its variability, i.e. geological features of the investigated area, the bio-available fraction of elements in the soils and the up-take of the plant, have been taken into account. Optimisation of an analytical procedure for the separation of Sr from its interferences and investigation of the analytical performances in terms of precision of used methodology have been carried out as well. This work highlighted a good match between the isotopic values monitored in the bio-available fraction of soils and their respective grape juices for almost all the investigated areas. The correlation with food satisfyingly improves when isotopic relative abundance values of branches vine are considered.

An analytical approach to Sr isotope ratio determination in Lambrusco wines for geographical traceability purposes

Geographical origin and authenticity of food are topics of interest for both consumers and producers. Among the different indicators used for traceability studies, (87)Sr/(86)Sr isotopic ratio has provided excellent results. In this study, two analytical approaches for wine sample pre-treatment, microwave and low temperature mineralisation, were investigated to develop accurate and precise analytical method for (87)Sr/(86)Sr determination. The two procedures led to comparable results (paired t-test, with t<tcrit). Furthermore, the precision of the whole analytical procedure was evaluated by using a control sample (wine sample), processed during each sample batch (calculated Relative Standard Deviation, RSD%, equal to 0.002%. Lambrusco PDO (Protected Designation of Origin) wines coming from four different vintages (2009, 2010, 2011 and 2012) were pre-treated according to the best procedure and their isotopic values were compared with isotopic data coming from (i) soils of their territory of origin and (ii) wines obtained by same grape varieties cultivated in different districts. The obtained results have shown no significant variability among the different vintages of wines and a perfect agreement between the isotopic range of the soils and wines has been observed. Nevertheless, the investigated indicator was not enough powerful to discriminate between similar products. To this regard, it is worth to note that more soil samples as well as wines coming from different districts will be considered to obtain more trustworthy results.

Optimization of a Dynamic Headspace – Thermal Desorption – Gas Chromatography/Mass Spectrometry procedure for the determination of furfurals in vinegars

The use of a Dynamic Headspace System (DHS) device combined with a Thermal Desorption Unit (TDU) interfaced to a Gas Chromatography/Mass Spectrometry (GC/MS) system is proposed for the determination of furfurals in oenological products. An experimental design protocol has been employed for the optimization of the instrumental settings concerning DHS and TDU extraction and desorption steps. It has been possible to individuate the following optimized conditions: incubation temperature 40°C, purge volume 800 mL, dry volume 1500 mL, TDU hold time 5 min and incubation time 10 min. The performance of two different SPE sorbents, namely Tenax TA and Tenax GR used for the furfurals trapping, was investigated too. The developed DHS sampling procedure showed good reproducibility values with a RSD% lower than 10% for all the monitored species. The optimized experimental settings have been used to determine furfurals in several vinegar samples obtained by traditional procedure starting from cooked grape musts, i.e. in Aceto Balsamico Tradizionale di Modena (ABTM). In fact, the control of these species is extremely important for quality and safety issues.

Densities and excess molar volumes of binary mixtures containing 1,2-dichloroethane + 2-methoxyethanol or 1,2-dimethoxyethane at different temperatures

Abstract Density of the 1,2-dichloroethane + 2-methoxyethanol or 1,2-dimethoxyethane binary mixtures have been measured at different temperatures over the complete composition range. Several experimental measurements have been used to check the validity of the relationships accounting for the dependence of the density on temperature and composition, useful to obtain interpolated values in correspondence of the experimental data gaps. Starting from the primary data, some derived quantities, such as partial molar volumes, excess and partial excess molar volumes, have been obtained. In these mixtures, V E is always positive for DCE + ME binaries, while an S-shaped dependence on composition at each temperature is obtained in DCE + DME system, showing positive values in the DCE rich-region and negative values at the opposite extreme. The results are compared and discussed to shed some light to the changes in molecular association and structural effects in these binary solvent systems.

Viscosimetric properties and internal structure of N,N-dimethylformamide + 1,2-dimethoxyethane binary mixtures

Abstract The kinematic viscosities (ν) of liquid binary mixtures of N,N-dimethylformamide and 1,2-dimethoxyethane were measured at 19 temperatures in the range −10⩽ t / °C ⩽ 80, employing the pure species and 9 their solutions covering the whole miscibility range expressed by the condition 0 ⩽ χi ⩽ 1. The measured values have been used to test some empirical equations of the type ν=ν(T), ν=ν(χi, and ν=ν(T,χi), in order to obtain useful correlation models with predictive ability in correspondence of the experimental data gaps. Starting from the experimental data, the excess kinematic viscosities (νE) have been calculated. Sign and magnitude of these quantities have been discussed in terms of type and nature of specific intermolecular interactions. Some derived quantities such as thermodynamic parameters of the viscous flow (ΔG∗, ΔH∗ and ΔS∗), have been calculated on the basis of Eyrings model. Furthermore, the fluidity of this binary solvent system was analysed and interpreted following Hildebrand and modified-Hildebrand correlation models.

The Ethane-1,2-diol + 2-methoxyethanol + 1,2-dimethoxyethane Ternary Solvent System: Density and Volume Properties at Different Temperatures

Abstract The density of the ethane-1,2-diol+2-methoxyethanol + 1,2-dimethoxyethane ternary mixtures has been measured at different temperatures ranging from-10 to 80° C, and over the whole composition range. The experimental data have been used to check the validity of some relationships accounting for the dependence of the density on temperature and composition, useful to evaluate the behaviour of this property in the whole temperature and composition domains. Starting from the primary data, some derived quantities, such as excess molar volumes, partial molar volumes and partial excess molar volumes, have been obtained. In these mixtures V E is generally negative at all the experimental conditions, showing the greatest deviations along the binary axes corresponding to the binary subsystems. The results are compared and discussed to get light to the changes in molecular association and structural effects in this solvent system.

The Impact of Chemometrics on Food Traceability

Abstract In the last decades, mankind has become totally aware about the importance of food quality: nowadays authentication and traceability are words of general use. Food authentication verifies how much a food is in accordance with its label description and law and it could be considered a further guarantee for the quality and safety of a foodstuff. The traceability of food could be considered an essential element in ensuring safety and high quality of food. The synergistic use of instrumental analytical techniques and chemometrics represents a promising way to obtain trustworthy results in the development of authenticity and traceability models. This chapter deals with the potentialities of chemometrics tools in resolving some real issues related to food traceability and authenticity. Particular attention will be paid to the use of some exploratory, classification, and discrimination techniques. In the first part of this chapter, a briefly description of European regulations ( Authenticity and Traceability: the European Union point of view ), and traceability and authenticity markers ( Authenticity and Traceability: a scientific point of view ) is reported. The second part is split into two sections: namely Food Authenticity and Food Traceability applications , where the main features and advantages of some chemometrics approaches are presented.

Use of X-ray diffraction technique and chemometrics to aid soil sampling strategies in traceability studies.

Aim of this work is to assess the potentialities of the X-ray powder diffraction technique as fingerprinting technique, i.e. as a preliminary tool to assess soil samples variability, in terms of geochemical features, in the context of food geographical traceability. A correct approach to sampling procedure is always a critical issue in scientific investigation. In particular, in food geographical traceability studies, where the cause-effect relations between the soil of origin and the final foodstuff is sought, a representative sampling of the territory under investigation is certainly an imperative. This research concerns a pilot study to investigate the field homogeneity with respect to both field extension and sampling depth, taking also into account the seasonal variability. Four Lambrusco production sites of the Modena district were considered. The X-Ray diffraction spectra, collected on the powder of each soil sample, were treated as fingerprint profiles to be deciphered by multivariate and multi-way data analysis, namely PCA and PARAFAC. The differentiation pattern observed in soil samples, as obtained by this fast and non-destructive analytical approach, well matches with the results obtained by characterization with other costly analytical techniques, such as ICP/MS, GFAAS, FAAS, etc. Thus, the proposed approach furnishes a rational basis to reduce the number of soil samples to be collected for further analytical characterization, i.e. metals content, isotopic ratio of radiogenic element, etc., while maintaining an exhaustive description of the investigated production areas.

Refractive properties of binary mixtures containing 1,2-dichloroethane + 2-methoxyethanol or 1,2-dimethoxyethane

Abstract Refractive index ( n ) and related properties such as molar refraction ( R ) have been investigated for DCE + ME and DCE + DME binary mixtures over the entire composition range, at different temperatures in the interval 0 ≤ t/°C ≤ 70. Some empirical and theoretical relationships have been applied to study the dependence of the measured and derived quantities on temperature and on binary composition. Furthermore, the excess functions n E , R E and the excess Kirkwood correlation parameters Δg have been examined, in order to identify the presence of solvent-cosolvent adducts in these binary solvent systems. The results obtained have been interpreted on the basis of specific intermolecular interactions between different species.

Kinematic Viscosities of Binary Liquid Mixtures of 2-Butanone with 1,2-Propanediol

Kinematic viscosities of the binary 2-butanone (1) + 1,2-propanediol (2) solvent system have been measured for mixtures covering the whole miscibility range expressed by 0 ≤ xi ≤ 1, at 19 temperatures in the range −10 ≤ t/°C ≤ 80. The measured values have been used to test empirical equations that express the kinematic viscosities as functions of the composition and temperature. Excess kinematic viscosities (νE) have also been calculated. Sign and magnitude of these quantities are discussed in terms of type and nature of specific intermolecular interactions. Furthermore, derived quantities such as thermodynamic parameters of viscous flow (ΔG‡, ΔH‡ and ΔS‡), are analyzed on the basis of Eyrings model. All the investigated excess mixing properties indicate the probable existence of stable two-component adducts in this binary solvent system.