1. Food Quality and Metabolomics Groups
Effects of storage conditions on the polar metabolite content of red wine revealed by untargeted HILIC-HRMS metabolomics
Panagiotis Arapitsasa*, Anna della Cortea, Helen Gikab, Luca Narduzzia#, Andrea Angelia, Fulvio Mattivia, Georgios Theodoridisc
aDepartment of Food Quality and Nutrition, Research and Innovation Centre, Fondazione Edmund Mach (FEM), Via E. Mach 1, 38010, San Michele all´Adige, Italy
bDepartment of Chemical Engineering, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece.
cDepartment of Chemistry, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece.
#Presenting author:
*Corresponding author:
Introduction:
Wines can be stored long time and in contrast to most food ageing is positively correlated with quality. However, wines exposed to sub-optimal domestic storage conditions undergo to chemical modifications which may damage their quality [1].
Main aim of this study was to develop a Hydrophilic Interaction Liquid Chromatography (HILIC) to complement reverse phase (RP) chromatography in global metabolomic fingerprinting, starting from a targeted HILIC-MS/MS method covering a wide set (135) of polar metabolites, dedicated to the analysis of grape and wine [2]. The final goal was to apply the optimized metabolic profiling method to the study the effect of typical domestic storage conditions as compared to optimum cellar conditions for five red wines and for a period of 24 months.
Domestic VS
Cellar
Method development:
Sample preparation: different dilution factors have been tested, evaluating peak shape (figure 1) and the total number of extracted features.
Eluents preparation: Ammonium formate concentration has been equiparated to 20 mM in both eluents to improve chromatography  stable retention times. Stock solution of Ammonium formate was the same for both eluents.
Overall system evaluation: A pilot experiment perfomed on a longer batch of injections to evaluate the overall system stability (figure 2).
Figure 1: effects of sample dilution on the peak shape. Samples have been diluted with Acetonitrile. As shown, peak shape becomes sharper in diluted samples. Best results have been obtained with dilution 1:2.
Figure 2: Total number of features of several pooled sample injections intervalled by blank injections. The similar number of features, injection after injection, assures the instrumental system stability.
Wine storage experiment:
Experimental: wines have been stored in cellar and domestic conditions for 24 months. “Cellar” condition was optimal, with controlled temperature (15-17 °C) and humidity. “Domestic” condition was sub-optimal, with uncontrolled humidity and temperature. 5 replicates for each time point were selected: 0, 6, 12, 18, 24 months.
Results: “Domestic” conditions determine a shift on the left side of the PCA (figure 3). OPLS-DA reported 29 putative biomarkers, some of which were the same of [1]. Most promising marker was amino-heptanedioic acid, showing a faster decrease in concentration in the domestic storage condition with similar trend for Pantothenic acid, as shown in figure 4.
Figure 3: PCA plot on the samples stored in cellar (blue dots), and domestic (red dots) conditions. Pooled samples injections (green dots) showed a good repeatability during the analysis.
Figure 4: trend plots of aminoheptanedioic acid (left) and Pantothenic acid (right) during the 5 time points of this experiment, compared for cellar (blue line) and domestic (green line) conditions.
Conclusions:
A novel untargeted HILIC-HRMS method has been established and validated for the detection of wine polar metabolites.
The method has been successfully applied to discriminate the metabolites undergoing to chemical modifications during sub-optimal wine storage conditions.
[1] (1) Arapitsas, P.; Speri, G.; Angeli, A.; Perenzoni, D.; Mattivi, F. Metabolomics 2014, 10, 816–832.
[2] (1) Gika, H. G.; Theodoridis, G. a.; Vrhovsek, U.; Mattivi, F. J. Chromatogr. A 2012, 1259, 121–127.
Food Quality and Metabolomics Groups
CHEMAN Y20