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…

Effects of progeny in the modulation of the response to water stress in isohydric and anisohydric varieties

Each grapevine variety has a specific water use regulation response under drought, and it is still unclear whether this regulation results from innate genotypic behavior (iso- and anisohydric), or is a response to environmental factors, namely recurrent water stress priming effects. In the present work, we explored the influence of the field-grown genotypes’ drought memory in the drought-response phenotype of their vegetative progenies, in Trincadeira (isohydric) and Castelão (anisohydric) varieties under a drought event followed by recovery in a glasshouse. Cuttings from both cultivars subjected to full irrigation (FI) and non-irrigation (NI) treatments for 5 consecutive years were used.

The importance of soil and geology in tasting terroir; a case history from the Willamette valley, Oregon

Wines differ from each other based on seven different factors: the type of grape; the bedrock geology and resulting soils; the climate; the soil hydrology; physiography of the site; the winemaker and the vineyard management techniques. The first five of these factors make up what the French call terroir, “the taste of the place”.

The role of molecular ecophysiology in terroir expression

Terroir is a complex concept which associates soil, climate, grape variety and cultural practices that include the training system and oenological techniques. It is a type of social construction with man at its centre. The typicality of a wine is also a social construction which is the result of an agreement among specialists vis à vis a given quality of the wine whose references are the wine’s origins (e.g. terroir) and taste.

Effects of winemaking practices on Pinot blanc quality

Two winemaking processes for Pinot blanc were investigated following the chemical and sensory profiles for 12 months, aiming at: i) determining the chemical and sensory profiles

INFLUENCE OF WINEMAKING VARIABLES AND VINEYARD LOCATIONS ON CHEMICAL AND SENSORY PROFILES OF SOUTH TYROLEAN PINOT BLANC

Pinot Blanc, an important grape variety grown in some mountain areas of Northern Italy such as South Tyrol over the last decades, with its cultivation covering 10.3% of the total vineyards, has compatible climatic conditions (e.g. heat requirements) which are normally found in the geographical areas of the mountain viticulture [1,2,3,4]. Climatic changes are hastening the growth of this variety at higher elevations, particularly for the production of high quality wine.