WAC 2022 banner
IVES 9 IVES Conference Series 9 WAC 9 WAC 2022 9 3 - WAC - Posters 9 SKIN AND SEED EXTRACTS DIFFERENTLY BEHAVE TOWARDS SALIVARY PROTEINS

SKIN AND SEED EXTRACTS DIFFERENTLY BEHAVE TOWARDS SALIVARY PROTEINS

Abstract

Polyphenols extracted from skins and seeds showed different sensory attributes including astringency and bitterness. In previous studies, it has been demonstrated that extracts obtained either from skins or seeds interact differently with salivary proteins. Red grape winemaking consists of a maceration of the whole berries in which both skins and seeds are mixed together; however, no information on the mutual influence that skins and seeds could have on the reactivity towards saliva of hydroalcoholic extracts is known. In this study, five different wine model solutions were prepared: the first one contained only skins(Sk), the second one contained only seeds(Sd) and the remaining three contained different sk/sd ratios, as detailed below:A(ratio 2:1 sk:sd), B(ratio 1:1 sk:sd) and C(ratio 1:2 sk:sd). HPLC analyses were performed to determine the content of total native anthocyanins, acetaldehyde and polymeric pigments. Iron reactive phenolics, BSA reactive tannins (BSArT), vanillin reactive flavans (VRF) were also determined. The potential astringency of red samples was evaluated in vitro by the Saliva Precipitation index (SPI). The results obtained highlighted important differences in the behavior of the samples as a function of the different sk:sd ratio. When sk and sd were simultaneously present (samples A,B and C), a significant lower content of anthocyanins with respect to Sk was observed. This was likely due to a possible adsorption of pigments on cell walls contained in pomaces. As the amount of seeds increased in the solutions containing also skins, the content of VRF,BSArT,PP and acetaldehyde linearly increased. After 24 months of aging under controlled conditions, all the trends observed at 0 time were confirmed and appeared to be enhanced. Concerning the interactions toward salivary proteins, as expected, sample Sd showed the highest SPI. Surprisingly, when skins were added to a model solution containing seeds, a decrease of SPI occurred, although VRF and BSArT increased. This suggests that anthocyanins and polymeric pigments in A, B and C samples determined a lower reactivity of compounds contained in the whole solution towards saliva proteins. SPI values are not correlated to the amount of VRF and BSArT in the samples. Results highlighted not only the important role of the sk:sd ratio in the extraction of compounds from berries, but also that of anthocyanins extracted from skins in decreasing the reactivity of grape compounds towards saliva.

DOI:

Publication date: June 27, 2022

Issue: WAC 2022

Type: Article

Authors

Francesco Errichiello, Antonio Guerriero, Luigi Picariello, Francesca Coppola, Alessandra Rinaldi, Martino Forino, Angelita Gambuti.

Presenting author

Francesco Errichiello – Department of Agricultural Sciences, Grape and Wine Science Division, University of Naples “Federico II”, Viale Italia (Angolo Via Perrottelli), 83100 Avellino, Italy.

Department of Agricultural Sciences, Grape and Wine Science Division, University of Naples “Federico II”, Viale Italia (Angolo Via Perrottelli), 83100 Avellino, Italy;Biolaffort, 126 Quai de la Souys, 33100 Bordeaux, France,

Contact the author

Keywords

skin/seed extract, anthocyanins, polymeric pigments, astringency

Tags

IVES Conference Series | WAC 2022

Citation

Related articles…

Modeling island and coastal vineyards potential in the context of climate change

Climate change impacts regional and local climates, which in turn affects the world’s wine regions. In the short term, these modifications rises issues about maintaining quality and style of wine, and in a longer term about the suitability of grape varieties and the sustainability of traditional wine regions. Thus, adaptation to climate change represents a major challenge for viticulture. In this context, island and coastal vineyards could become coveted areas due to their specific climatic conditions. In regions subject to warming, the proximity of the sea can moderate extremes temperatures, which could be an advantage for wine. However, coastal and island areas are particular prized spaces and subject to multiple pressures that make the establishment or extension of viticulture complex.
In this perspective, it seems relevant to assess the potentialities of coastal and island areas for viticulture. This contribution will present a spatial optimization model that tends to characterize most suitable agroclimatic patterns in historical or emerging vineyards according to different scenarios. Thanks to an in-depth bibliography a global inventory of coastal and insular vineyards on a worldwide scale has been realized. Relevant criteria have been identified to describe the specificities of these vineyards. They are used as input data in the optimization process, which will optimize some objectives and spatial aspects. According to a predefined scenario, the objectives are set in three main categories associated with climatic characteristics, vineyards characteristics and management strategies. At the end of this optimization process, a series of maps presents the different spatial configurations that maximize the scenario objectives.

Investigating the impact of grape exposure and UV radiations on rotundone in Vitis vinifera L. Tardif grapes under field trial conditions

Rotundone is the main aroma compound responsible for peppery notes in wines whose biosynthesis is negatively affected by heat and drought. Through the alteration of precipitation regime and the increase in temperature during maturation, climate change is expected to affect wine peppery typicality. In this context there is a demand for developing sustainable viticultural strategies to enhance rotundone accumulation or limit its degradation. It was recently proposed that ultraviolet (UV) radiations could stimulate rotundone production. The aim of this study was to investigate under field trial conditions the impact of grape exposure and UV treatments on rotundone in Vitis vinifera L. Tardif, an almost extinct grape variety from south-west France that can express particularly high rotundone levels. Four different treatments were compared in 2021 to a control treatment using a randomised complete block design with three replications per treatment. Grape exposure was manipulated through early or late defoliation. Leaf and laterals shoots were removed at Eichorn Lorenz growth stages 32 or 34 on the morning-sun side of the canopy. During grape maturation, UV radiations were either reduced by 99% by installing UV radiation-shielding sheets, or applied four times using the Boxilumix™ non thermal device (Asclepios Tech, Tournefeuille) with the aim of activating plant signalling pathway. Loggers displayed in solar radiation shields were used to assess the effect of such shielding sheets on air temperature within the bunch zone. The composition of grapes subjected to these treatments will be soon analysed for their rotundone content and basic classical laboratory analyses. Grapes will be harvested to elaborate wines under standardized small-scale vinification conditions (60kg) that will be assessed by a trained sensory panel.

How can historical cultivars mitigate the effects of climate change?

IFV, INRAe and the national network “Partenaires de la Sélection Vigne” representing 37 organizations from the different wine regions, have been working increasingly closely over the last 2 decades towards the preservation of the French varietal patrimony. There are approximately 600 patrimonial varieties according to INRAe and SupAgro Montpellier experts, including ancient cultivars (400) and intravarietal crossbreeds obtained since the 19th century. In the context of a drastic reduction in such varieties from the mid 1980’s in favor of mainstream varieties, it was essential to carry out an inventory of old vines and vineyards. INRAe Vassal collection plays a key role here as it holds the largest diversity available, along with a rich bibliography and herbariums, offering us the opportunity to document and double check the identity of a cultivar, consolidating the expertise of ampelographers. The work is carried out in several stages, from verifying the existence of a variety in a small region, through to rehabilitation. During this session, the authors present the process that leads to the official registration of a variety. After this, IFV selection center takes over to initiate the process of selection and propagation. A specific focus within regions such as the Alps, Champagne and the South-West will provide details of the full procedure. Bia, Bouysselet, Chardonnay rose, Mecle and the aptly named Tardif, are some of the cultivars that have followed this procedure. Furthermore, a recent regulation established by INAO on “varieties of interest for adaptation purposes” might boost uptake by growers. Since 2006, 36 historical cultivars have been registered. Most of these have been neglected in the past due to late maturity, lack of sugar and high titratable acidity at harvest time. Such characteristics are today considered as positive qualities, not only in mitigation of the effects of climate change, but also as an opportunity for restoring diversity…

Adaptability of grapevines to climate change: characterization of phenology and sugar accumulation of 50 varieties, under hot climate conditions

Climate is the major factor influencing the dynamics of the vegetative cycle and can determine the timing of phenological periods. Knowledge of the phenology of varieties, their chronological duration, and thermal requirements, allows not only for the better management of interventions in the vineyard, but also to predict the varieties’ behaviour in a scenario of climate change, giving the wine producer the possibility of selecting the grape varieties that are best adapted to the climatic conditions of a certain terroir. In 2014, Symington Family Estates, Vinhos, established two grape variety libraries in two different places with distinctive climate conditions (Douro Superior, and Cima Corgo), with the commitment of contributing to a deeper agronomic and oenological understanding of some grape varieties, in hot climate conditions. In these research vineyards are represented local varieties that are important in the regional and national viticulture, but also others that have over time been forgotten — as well as five international reference cultivars. From 2017 to 2021, phenological observations have been made three times a week, following a defined protocol, to determine the average dates of budbreak, flowering and veraison. With the climate data of each location, the thermal requirements of each variety and the chronological duration of each phase have been calculated. During maturation, berry samples have been gathered weekly to study the dynamics of sugar accumulation, between other parameters. The data was analysed applying phenological and sugar accumulation models available in literature. The results obtained show significant differences between the varieties over several parameters, from the chronological duration and thermal requirements to complete the various stages of development, to the differences between the two locations, confirming the influence of the climate on phenology and the stages of maturation, in these specific conditions.

Analysis of Cabernet Sauvignon and Aglianico winegrape (V. vinifera L.) responses to different pedo-climatic environments in southern Italy

Water deficit is one of the most important effects of climate change able to affect agricultural sectors. In general, it determines a reduction in biomass production, and for some plants, as in the case of grapevine, it can endorse fruit quality. The monitoring and management of plant water stress in the vineyard