Differentiation and characterization of Spanish fortified wines with protected designation of origin based on volatiles using multivariate approaches

Abstract

Spain is one of the main producers of high-quality fortified wines. Particularly some of them elaborated in Andalusia have acquired a great prestige for being unique due to their production in a specific geographical area with traditional methods, the grape variety used, the climate and the soil. Such is their distinguishing feature achieved that they have been protected by the European Union with the indication “Protected Designation of Origin” (PDO). Thus, there are four PDO of fortified wines in Andalucía (‘Condado de Huelva’, ‘Jerez Xérès Sherry’, ‘Manzanilla Sanlúcar de Barrameda’, and ‘Montilla-Moriles’). Furthermore, within each PDO,there are different categories according to their particular characteristics and winemaking conditions such as the aging process. Hence, Finos and Manzanillas wines are produced by biological aging, Oloroso wines by oxidative aging, and wines such as Amontillado and Palo Cortado wines share both types of aging during their production. The great diversity of high-quality wines on the market and the increase in their demand makes it is necessary to characterize them in order to establish quality and authenticity control parameters, thus protecting and assuring consumers that the product they are purchasing on the market has the quality and characteristics declared. The focus on the aroma has been object of study for the characterization of these products since it is considered one of the most relevant quality criteria for wine. Despite the fact that some authors have previously studied the volatile profile of some of these fortified PDO wines, scarce research has been done to assess the volatile composition of the four Spanish PDO fortified wines [1,2,3]. In this context, the aim of this work was to study and compare the characteristic volatile profile of different fortified wines from each Spanish PDO by headspace solid phase micro-extraction (HS-SPME) in conjunction with gas chromatography-mass spectrometry (GC-MS). Chemometric techniques such as PARAFAC2 was applied to reduce the problems associated with GC-MS analysis of complex mixtures and to obtain the maximum information of the volatile profile for distinguishing between samples. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were applied to study the differentiation of the samples. Volatile composition of the samples allowed the differentiation and classification of the different fortified wines based on the presence of certain compounds which could be considered markers of quality and authenticity for each PDO and type of wine.

References

[1] García-Moreno et al., (2021). LWT – Food Science and Technology,140,110706.
[2] Hevia, K., Castro, R., Natera, R., González-García, J. A., Barroso, C. G., & Durán-Guerrero, E. (2016). Chromatographia, 79(11–12), 763–771.
[3] Zea, L., Moyano, L., Moreno, J., Cortes, B., & Medina, M. (2001). Food Chemistry, 75(1), 79–84.