Beginning the analysis of the 2023 harvest
The Rueda Enological Station has once again become the setting for a new meeting of the MINORSENS project. During the meeting, the Agricultural Technology Institute of Castilla y León provided grape, must, and wine samples from the 2023 harvest of minority varieties to the University of Valladolid and the Polytechnic Institute of Bragança for analysis. We are thus beginning the next stage of physical-chemical characterization of this first batch of grapes of minority varieties, musts, and wines produced last year 2023. Additionally, we agreed on a homogeneous protocol for defrosting samples and had the opportunity to taste a small selection of wines made from the varieties: Puesta en Cruz (from Arribes, white wine produced in 2023), Gajo Arroba (from Arribes, red wine produced in 2023), and Tinto Jeromo (also from Arribes, red wine produced in 2023).
MINORSENS and technology: the electronic nose and tongue
One of the innovations of the MINORSENS project lies in the use of electronic methods for the analysis of musts and wines, something that until now has been carried out through conventional physical-chemical and sensory methods. But… what exactly do these tools consist of?
The electronic nose is based on a network of resistive sensors that have specific hardware and pattern recognition software. The objective is to analyze the volatile organic compounds of musts and wines by mimicking, in a simplified way, the olfactory system of mammals. It is part of a research area called biomimetics, that is, applying functional schemes from nature to electronic tools created by humans. The goal of this device is to obtain objective measurements that do not depend on human subjectivity. The sensation that a smell provokes in us and the meaning that our brain automatically interprets can somehow bias the olfactory analysis of a wine.
The sensors used by the electronic nose are based on metal oxides. Several of these sensors are required because each one is capable of analyzing a single odor or component of the sample. During the development of the project, the most suitable sensors will be chosen to detect the components present in the headspace of the selected musts and wines. In addition, the functioning of the fibers responsible for absorbing the volatile components will be evaluated.
For its part, the bioelectronic tongue is also a biomimetic system inspired, in this case, by the sense of taste. It uses a novel network of electrochemical nanosensors and nanobiosensors capable of detecting compounds such as sugars, phenols, polyphenols, and organic acids. The polyphenol content of wine is an important parameter in the wine sector. This type of substance shows antioxidant activity, that is, they help neutralize free radicals and protect cells from oxidative damage. This means that polyphenols can prevent premature aging and reduce the risk of certain diseases. From a quality perspective, polyphenols give wine its color, texture, bitterness, and astringency, so quantifying them is key to controlling the type of wine we want to produce.
Just like the electronic nose, the bioelectronic tongue uses pattern recognition software in which supervised and unsupervised chemometric techniques are implemented. Thanks to the bioelectronic tongue, we will be able to analyze the quality of musts and wines objectively and establish correlations with chemical parameters. In the future, the bioelectronic tongue could be a portable device used in wineries as another work tool to help ensure the quality and unique characteristics of wines.
