IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 HPLC and SEC analysis on the flavonoids and the skin cell wall material of Merlot berries reveals new insights into the study of the phenolic maturity

HPLC and SEC analysis on the flavonoids and the skin cell wall material of Merlot berries reveals new insights into the study of the phenolic maturity

Abstract

Anthocyanins and tannins contribute to important sensorial traits of red wines, such as color and mouthfeel attributes. Despite the evolution of flavonoids during berry ripening has been extensively studied and the properties of skin and flesh cell wall material (CWM) to bind tannins were described, the mechanism determining the reduction of unpleasant astringency in the last phases of ripening remained uncertain. In this regard, the present research was aimed to better understand the factors involved in the phenolic maturity by a detailed evaluation of the flavonoid characteristics and the CWM properties, in the last weeks before harvest and at harvest. The study was conducted in 2014 and 2015 in a Merlot vineyard located in the hills near Bologna (north of Italy). The analysis of flavonoids and skin CWM was performed on berries sampled 20 and 10 days before harvest and at harvest. Exhaustive extractions were conducted to analyze total anthocyanins and tannins (skin and seed separately), while a model hydroalcoholic solution was used for their extractable portion. Moreover, binding reactions between the CWM and an enological seed tannin were performed to evaluate the magnitude of tannin precipitation and the composition of the  tannins remained in solution.HPLC analysis showed the increase of total and extractable anthocyanins during ripening, while no change was found in the concentration, composition and mean degree of polymerization (mDP) of skin and seed tannins. Also, the composition of CWM did not change significantly, but the tendency of proteins to increase until the harvest was noticed in both years. Moreover, CWM bound increasing quantity of the enological seed tannin during ripening, favoring, in particular, the precipitation of the tannins with higher mDP and of the galloilated forms, which are reported to be the compounds more involved in the perception of unpleasant astringency. The analysis performed by SEC confirmed that CWM bound preferentially the tannins of high molecular mass (MM), while lower amounts of medium MM tannins and negligible quantities of low MM tannins interacted with CWM. Our results confirmed that more ripen berries may release higher amounts of anthocyanins and allowed us to hypothesize that CWM may play a role in the decrease of astringency which is associated with the progression of ripening.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Allegro Gianluca1, Bautista-Ortín Ana-Belén2, Gómez-Plaza Encarna2, Pastore Chiara1,  Valentini Gabriele1, Mazzoleni Riccardo1 and Filippetti Ilaria1

1Department of Agricultural and Food Sciences – University of Bologna, Viale Fanin 46, 40127, Bologna, Italy
2Departamento de Tecnología de Alimentos, Nutrición y Bromatología – Universidad de Murcia (Spain)

Contact the author

Keywords

anthocyanins, astringency, ripening, tannins, Vitis vinifera

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Varietal differences between Shiraz and Cabernet sauvignon wines revealed by yeast metabolism

This study investigated if compositional differences between Shiraz and Cabernet Sauvignon grape varieties could influence the production of yeast-derived compounds. This work was based on the analysis of 40 experimental red wines made in triplicate fermentations from grapes harvested from two consecutive vintages in New South Wales (Australia). Grapes were picked at three maturity stages using berry sugar accumulation as physiological indicator, from nine commercial vineyards located in three different climatic regions (temperate, temperate-warm and warm-hot). A range of 30 yeast-derived wine volatiles including esters and alcohols were quantified by HS/SPME-GC/MS. Ammonia, amino-acids and lipids were analysed in the corresponding grapes. The juice total soluble solids (°Brix) in addition to the wine alcohol and residual sugar levels were also measured. The influence of grape maturity on wine ester composition was also variety dependent, particularly for higher alcohol acetate and ethyl ester of branched acids. This study highlights that varietal differences observed in Shiraz and Cabernet Sauvignon wines involve fermentation-derived compounds irrespective of the site (soil, climate, viticultural practices).

A applied viticultural zoning, based on the “secteurs de la reference” methodology, in the Cognac vineyard (France)

Dans les Charentes, en réponse à une crise de production du vignoble destiné à la production de Cognac, un plan de diversification viticole pour des vins de pays de qualité est mis en place. Il nécessite une connaissance des sols et de leurs caractéristiques viticoles pour orienter le choix des types de vins et adapter l’itinéraire technique de production.

The concept of « terroir »: what does that mean ? What is it useful for ? French young adults perception

Far from complicated discussions on the relevant way to define « terroir », this article deals with the social perception that French young adults (aged from 18 to 30) have of this concept and the way it can help them to become wine consumers.

The environmental footprint of selected vineyard management practices: A case study from Logroño (La Rioja) Spain

Viticulture is globally important for socioeconomic and environmental reasons. The EU is globally leading grape and wine production, and Spain is among the top grape and wine producers. As climate change affects viticulture, mitigation and adaptation are crucial for protecting grape production. In this research work, data on viticultural management practices such as soil cultivation, irrigation, energy, machinery, plant protection and the use of fertilizers from vineyards located in Logroño (La Rioja) have been obtained.

Revisiting esters hydrolysis in young white wines

Esters play an essential role in the young white wines’ fruity expression, particularly the groups of ethyl esters of fatty acids (EEFAs) and higher alcohol acetates (HAAs) [1]. However, generally, these groups of esters decrease relatively fast during the first two years of ageing [1, 2].