Abstract
Sherry wine vinegar is a Spanish gourmet product under Protected Designation of Origin (PDO). Before a vinegar can be labeled as Sherry vinegar, the product must meet certain requirements as established by its PDO, which, in this case, means that it has been produced following the traditional solera and criadera ageing system. The quality of the vinegar is determined by many factors such as the raw material, the acetification process or the aging system. For this reason, mainly producers, but also consumers, would benefit from the employment of effective analytical tools that allow precisely determining the origin and quality of vinegar. In the present study, a total of 48 Sherry vinegar samples manufactured from three different starting wines (Palomino Fino, Moscatel, and Pedro Ximénez wine) were analyzed by Fourier-transform infrared (FT-IR) spectroscopy. The spectroscopic data were combined with unsupervised exploratory techniques such as hierarchical cluster analysis (HCA) and principal component analysis (PCA), as well as other nonparametric supervised techniques, namely, support vector machine (SVM) and random forest (RF), for the characterization of the samples. The HCA and PCA results present a clear grouping trend of the vinegar samples according to their raw materials. SVM in combination with leave-one-out cross-validation (LOOCV) successfully classified 100% of the samples, according to the type of wine used for their production. The RF method allowed selecting the most important variables to develop the characteristic fingerprint (“spectralprint”) of the vinegar samples according to their starting wine. Furthermore, the RF model reached 100% accuracy for both LOOCV and out-of-bag (OOB) sets.
Highlights
The production of high-quality vinegar is increasingly important for manufacturers as consumers’ demand for a high-quality product presents a growing trend
In order to preserve and guarantee the quality of certain vinegars associated with specific geographical areas, the European Union recognizes these vinegars with the category of Protected Designation of Origin (PDO) (Council Regulation (EC) 510/2006)
The first step consists of the acetification procedure, which can be performed by traditional or industrial methods
Summary
The production of high-quality vinegar is increasingly important for manufacturers as consumers’ demand for a high-quality product presents a growing trend. In order to preserve and guarantee the quality of certain vinegars associated with specific geographical areas, the European Union recognizes these vinegars with the category of Protected Designation of Origin (PDO) (Council Regulation (EC) 510/2006) Such is the case of Sherry wine vinegar, from the Jerez-Xérès-Sherry, Manzanilla de Sanlúcar, and Vinagre de Jerez PDO region (in SW Spain). The quality of this PDO vinegar is related to the raw material (i.e., the grape variety), the production process, the type of cask used (America oak barrels), and the aging method [2] This gourmet-grade wine vinegar is produced from high-quality Sherry wines which are, in turn, protected by a PDO that establishes very specific and traditional aging methods [3]. According to European Regulations, there are three categories of PDO Sherry vinegars depending on their aging time in oak wood barrels as follows: Vinagre de Jerez (at least 6 months of aging time), Vinagre de Jerez Reserva (at least 2 years of aging time), and Vinagre de Jerez Gran
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
