OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 OENO IVAS 9 OENO IVAS 2019 9 Analysis and composition of grapes, wines, wine spirits 9 Comparison of tannin analysis by protein precipitation and normal-phase HPLC

Comparison of tannin analysis by protein precipitation and normal-phase HPLC

Abstract

Tannins are a heterogenous class of polymeric phenolics found in grapes, oak barrels and wine. In red wine tannins are primarily responsible for astringency, though they also have an important role in reacting with and stabilizing pigments. There are numerous sub-classes of tannins found in wine but they all share structural heterogeneity within each sub-class, with varied polymer composition, configuration and length. 

Numerous methodologies exist for the quantification of tannins, however, protein precipitation using bovine serum albumin has proved itself useful due to its strong correlation to the sensory perception of astringency and the basic instruments required for the method. Though the method can yield valuable insights into tannin composition, it cannot be automated easily and necessitates well-trained personnel. 

RP-HPLC analysis has been used for the quantification of low molecular phenolic compounds for a long time, but it is not suitable for the quantification of tannins. A normal-phase (NP)-HPLC method using a ternary solvent system is suggested, which is able to separate the phenolic compounds from red wine into three major fractions. Comparison with standard phenolic compounds allowed the characterization and quantification of these fractions and the results were compared to those obtained by protein precipitation.

DOI:

Publication date: June 23, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Jan-Peter Hensen, Ingrid Weilack, Fabian Weber, Andreas Schieber, James Harbertson

University of Bonn Institute of Nutritional and Food Sciences, Molecular Food Technology Endenicher Allee 19b D-53115 Bonn Germany 

Contact the author

Keywords

Tannin analysis, Protein Precipitation Assay, NP-HPLC

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

Utilizing ozone for the management of powdery mildew (Erysiphe necator Schwein.) in vineyards: potential and challenges

Powdery mildew, caused by fungal pathogens, poses a significant threat to grapevines in the DOCa Rioja region. In efforts to improve control strategies while reducing reliance on conventional phytosanitary products, ozone could constitute a potential alternative. However, it has short persistence, thus requiring frequent treatments. This study aimed to assess the suitability of ozone as an active substance for controlling powdery mildew within a phytosanitary strategy aimed at reducing conventional phytosanitary product usage. The strategy integrating ozone with conventional products yielded powdery mildew levels comparable to conventional treatments in both disease incidence and severity.

Contribution of Piperitone to the mint nuances perceived in the aging bouquet of red Bordeaux wines

During the tasting of a fine, old wine, the aromas generated in the glass are intertwined in an intimate, complex manner, expressing the fragrance of the aging bouquet. This aging bouquet, which develops during bottle storage through a complex transformation process, may result in a broad palette of nuances. Among these, undergrowth, truffle, toasted, spicy, licorice, fresh red- and black-berry fruit and mint descriptors were recently identified as features of its olfactory representation for red Bordeaux wines. Although a targeted chemical approach focusing on volatile sulfur compounds revealed the role played by dimethyl sulfide, 2-furanmethanethiol, and 3-sulfanylhexanol as molecular markers of the typicality of the wine aging bouquet of red Bordeaux wines, its chemical transcription has only partially been elucidated.

Understanding the expression of gene families involved in anthocyanin biosynthesis during berry ripening: Tannat as a case study

The quality of wine is assessed, among other things, by its color, which is mainly due to its anthocyanin content. These pigments are polyphenols that give red, purple and blue hues depending on the relative proportion of anthocyanins produced by the action of flavonoid 3’5′ hydroxylase (delphinidin-3-glucoside, petunidin-3-glucoside, malvidin-3-glucoside) or flavonoid 3′ hydroxylase (cyanidin-3-glucoside, peonidin-3-glucoside). To study the genes involved in this biosynthetic pathway, we focused on Vitis vinifera cv. Tannat, known for producing wines with higher anthocyanin content and darker purple color compared to most red grape varieties. In this work, we have performed RNA-Seq analysis of skins during berry development, taking green and red berries at 50% veraison as separate samples, as an experimental strategy to focus on the differential expression of genes of interest.

PulvéLab: an experimental vineyard for innovation in precision spraying

One of the ways to reduce the use of pesticides is to adapt their dosage to the needs of the plant by using variable rate technology for managing field spatial variability. The recent evolution of technologies in the field of robotics, mechatronics and new information and communication technologies

The use of unripe frozen musts for modulating wine characteristics throughout acidity correction – effects on volatile and amino acid composition

As environmental issues come more to the fore, vineyards residues are being looked at as solutions rather than problems. Aiming to develop a sustainable methodology for musts acidity correction in the process of winemaking, much needed in warm regions, the present study was performed according to Circular Economy values.