Enoforum 2021
IVES 9 IVES Conference Series 9 Enoforum Web 9 Enoforum Web Conference 2021 9 Cellar session 9 Relation between phenolic content, antioxidant capacity, oxygen consumption rate of diverse tannins

Relation between phenolic content, antioxidant capacity, oxygen consumption rate of diverse tannins

Abstract

The work was aimed at comparing some analytical methods used to characterize oenological tannins and the measure of oxygen consumption rate (OCR), in order to provide oenologists with a rapid method to test the antioxidant capacity of tannin based products and a tool to choose the best suited product for each purpose. Seven tannins with different botanical origin were studied by determining the polyphenolic content (Folin-Ciocalteau assay, GAE%; Total Polyphenols Index, TPI%; Phloroglucinolysis, CT%), antiradical activity (DPPH), reducing capacity (FRAP), redox properties (Linear Sweep Voltammetry, LSV). The OCR was measured with a noninvasive luminescence-based technology in an oxygen saturated model wine solution, containing transition metals and metabisulphite to better simulate the oxidative conditions. The results showed a high variability in polyphenolic content due to the botanical origin of tannins. The OCR determined over 21 days was described by quadratic equations, with coefficients varying with the dose and botanical origin of tannins and with SO2 concentration. The tannins ranked differently for antioxidant capacity, depending on the kind of test. The OCR was correlated with the LSV and FRAP indexes. The Factor Analysis of data distinguished three causes of variability between tannins (3 Factors) and the analytical parameters describing them: 1) the richness in polyphenols (First Factor, explaining the 34.02% of the total data variability), described by GAE%, TPI%, DPPH; 2) the tannin typology (Second Factor, 27.4%), described by LSV and CT%; 3) the oxygen consumption rate (Third Factor, 30.00%), described by OCR, LSV, FRAP.

DOI:

Publication date: April 23, 2021

Issue: Enoforum 2021

Type: Article

Authors

Silvia Mottaa, Massimo Guaitaa, Claudio Cassinob, Antonella Bossoa

a Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria – Centro di Ricerca Viticoltura ed Enologia, via P. Micca 35, 14100 Asti, Italy
b Dipartimento di Scienze e Innovazione Tecnologica, Università degli Studi del Piemonte Orientale, Viale T. Michel 11, 15121 Alessandria, Italy

Contact the author

Tags

Enoforum 2021 | IVES Conference Series

Citation

Related articles…

Sensory and chemical profiles of Cabernet Sauvignon wines exposed to different irrigation regimes during heatwaves

Heatwaves, defined as three or more consecutive days above average historical maximum temperatures, are having a significant impact on agricultural crop yields and quality, especially in arid or semi-arid regions with reduced water availability during the growing season.

MAPPING OF GAS-PHASE CO₂ IN THE HEADSPACE OF CHAMPAGNE GLASSES BY USING AN INFRARED LASER SENSOR UNDER STATIC TASTING CONDITIONS

From the chemical angle, Champagne wines are complex hydro-alcoholic mixtures supersaturated with dissolved carbon dioxide (CO₂). During the pouring process and throughout the several minutes of tasting, the headspace of a champagne glass is progressively invaded by many chemical species, including gas-phase CO₂ in large majority. CO₂ bubbles nucleated in the glass and collapsing at the champagne surface act indeed as a continuous paternoster lift for aromas throughout champagne or sparkling wine tasting [1]. Nevertheless, inhaling a gas space with a concentration of gaseous CO₂ close to 30% and higher triggers a very unpleasant tingling sensation, the so-called “carbonic bite”, which might completely perturb the perception of the wine’s bouquet.

An internet-based gis application for vineyard site assessment in the U.S. and matching grape variety to site

Vineyard site selection and determination of adapted grape varieties for a site are the most fundamental factors contributing to vineyard success, but can be challenging to ascertain

Crop water stress index as a tool to estimate vine water status

Crop Water Stress Index (CWSI) has long been a ratio to quantify relative plant water status in several crop and woody plants. Given its rather well relationship to either leaf or stem water potential and the feasibility to sample big vineyard areas as well as to collect quite a huge quantity of data with airborne cameras and image processing applications, it is being studied as a tool for irrigation monitoring in commercial vineyards. The objective of this paper was to know if CWSI estimated by measuring leaf temperature with an infrared hand held camera could be used to substitute the measure of stem water potential (SWP) without losing accuracy of plant water status measure.

Carbon isotope discrimination in berry juice sugars: changes in response to soil water deficits across a range of vitis vinifera cultivars

In wine producing regions around the world, climate change has the potential to decrease the frequency and amount of precipitation and increase average and extreme temperatures. This will lower soil water availability and increase evaporative demand, thereby increasing the frequency and intensity of water deficit experienced in vineyards. Among other things, grapevines manage water deficit by regulating stomatal closure. The dynamics of this regulation, however, have not been well characterized across the range of Vitis vinifera cultivars. Providing a method to understand how different cultivars regulate their stomata, and hence water use in response to changes in soil water deficits will help growers manage vineyards and select plant material to better meet quality and yield objectives in a changing climate.