Device for measuring tannins in a liquid

The invention consists of an innovative analytical method and a device able to quantify the amount of tannins in wines and other oenological products

Title of the patent Sistema, metodo e dispositivo per la rilevazione di tannini in un liquido
Thematic area Agro-food
Ownership Alma Mater Studiorum – Università di Bologna
Inventors Luigi Ragni, Arianna Ricci, Giuseppina Parpinello, Andrea Versari, Eleonora Iaccheri
Protection International
Licensing status Available for licensing agreements
Keywords Tannins, wine, enology, turbidity; optical device; pulsed photometry; selected wavelength
Filed on Feb 22, 2019

Tannins are natural polymers/macromolecules produced as secondary metabolites by plants, for protective purposes. They are widely investigated in food, nutritional, and pharmaceutical industries, due to their biological, technological and nutritional properties, and their high bioactivity. Wine and oenological derivatives exemplify the importance of tannin in the food industry, since the content of tannins (procyanidins) in grapes and their extractability during the winemaking process affect the sensory properties (i.e. body and astringency), the evolution of color components, the shelf-life and the physico- chemical stability of wines. Tannin content during the winemaking process is a highly valuable technological parameter, nevertheless it requires expensive and time-consuming analytical methods for its determination, which is often not suitable for the wine industry.

The proposed method allows direct measurement of tannins in wines without the need for sample preparation, purification or separation techniques. The chemical reaction on which the measurement is based, and the technology of the patented optical device, can be easily reproduced.

Since the simplicity of the whole experimental apparatus, it is possible to hypothesize the translation of the proposed method into a small dedicated analytical device, equipped with processing software and a data-sharing system that allows to implement the calibration and further improve the goodness of the determinations. A portable device of this type could be easily used even by non-specialized personnel, able to use promptly the result obtained, useful for rapid interventions in the production process.

The method is easy to perform and does not require complex preparation of sample and reagents. The optical device used for this method could be easily miniaturized to obtain a portable device, and equipped with a software and a display for rapid sampling along the supply chain.

Moreover, the proposed method could be evaluated for measuring the tannin content in different matrices, supporting specific applications in the food, nutraceutical, and pharmaceutical industries.