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…

Impact of climate variability and change on grape yield in Italy

Viticulture is entangled with weather and climate. Therefore, areas currently suitable for grape production can be challenged by climate change. Winegrowers in Italy already experiences the effect of climate change, especially in the form of warmer growing season, more frequent drought periods, and increased frequency of weather extremes.
The aim of this study is to investigate the impact of climate variability and change on grape yield in Italy to provide winegrowers the information needed to make their business more sustainable and resilient to climate change. We computed a specific range of bioclimatic indices, selected by the International Organisation of Vine and Wine (OIV), and correlated them to grape yield data. We have worked in collaboration with some wine consortiums in northern and central Italy, which provided grape yield data for our analysis.
Using climate variables from the E-OBS dataset we investigate how the bioclimatic indices changed in the past, and the impact of this change on grape productivity in the study areas. The climate impact on productivity is also investigated by using high-resolution convection-permitting models (CPMs – 2.2 horizontal resolution), with the purpose of estimating productivity in future emission scenarios. The CPMs are likely the best available option for this kind of impact studies since they allow a better representation of small-scale processes and features, explicitly resolve deep convection, and show an improved representation of extremes. In our study, we also compare CPMs with regional climate models (RCMs – 12 km horizontal resolution) to assess the added value of high-resolution models for impact studies. Further development of our study will lead to assessing the future suitability for vine cultivation and could lead to the construction of a statistical model for future projection of grape yield.

Different soil types and relief influence the quality of Merlot grapes in a relatively small area in the Vipava Valley (Slovenia) in relation to the vine water status

Besides location and microclimatic conditions, soil plays an important role in the quality of grapes and wine. Soil properties influence…

Evaluation of climate change impacts at the Portuguese Dão terroir over the last decades: observed effects on bioclimatic indices and grapevine phenology

In the last decades the growers of the Portuguese Dão winegrowing region (center of Portugal) are experiencing changes in climate that are influencing either grape phenology berry health and ripening. Aiming to study the relationships between climate indices (CI), seasonal weather and grapevine phenology, in this work long-term climate and phenological data collected at the experimental vineyard of the Portuguese Dão research centre between 1958 and 2019 (61 years) for the red variety Touriga Nacional, was analyzed. The trends over time for the classical temperature-based indices (Growing Season Temperature – GST -, Growing Degree Days – GDD, Huglin Index – HI and Cool Night Index – CI) presented a significantly positive slope while the Dryness Index (DI) showed a negative trend over the last 61 years. Regarding grapevine phenology, an average advance of 4.5 days per decade in the harvest day was observed throughout the last 61 years. Consequently, the weather conditions during the ripening period have changed, showing an increasing trend over time in the average temperature (higher magnitude in the maximum than in the minimum temperature) and a decrease in the accumulated rainfall. A regression analysis showed that ~50% of harvest date variability over years was explained by the temperature-based indices variability. These observed effects of climate change on bioclimatic indices and corresponding anticipation of harvest date can still be considered advantageous for the Dão terroir as it allows to achieve an optimal berry ripening before the common equinox rains and, therefore, avoid the potential negative impacts of the rainfall on berry health and composition.

The potential of multispectral/hyperspectral technologies for early detection of “flavescence dorée” in a Portuguese vineyard

“Flavescence dorée” (FD) is a grapevine quarantine disease associated with phytoplasmas and transmitted to healthy plants by insect vectors, mainly Scaphoideus titanus. Infected plants usually develop symptoms of stunted growth, unripe cane wood, leaf rolling, leaf yellowing or reddening, and shrivelled berries. Since plants can remain symptomless up to four years, they may act as reservoirs of FD contributing to the spread of the disease. So far, conventional management strategies rely mainly on the insecticide treatments, uprooting of infected plants and use of phytoplasma-free propagation material. However, these strategies are costly and could have undesirable environmental impacts. Thus, the development of sustainable and noninvasive approaches for early detection of FD and its management are of great importance to reduce disease spread and select the best cultural practices and treatments. The present study aimed to evaluate if multispectral/hyperspectral technologies can be used to detect FD before the appearance of the first symptoms and if infected grapevines display a spectral imaging fingerprint. To that end, physiological parameters (leaf area, chlorophyll content and photosynthetic rate) were collected in concomitance to the measurements of plant reflectance (using both a portable apparatus and a remote sensing drone). Measurements were performed in two leaves of 8 healthy and 8 FD-infected grapevines, at four timepoints: before the development of disease symptoms (21st June); and after symptoms appearance (ii) at veraison (2nd August); at post-veraison (11th September); and at harvest (25th September). At all timepoints, FD infected plants revealed a significant decrease in the studied physiological parameters, with a positive correlation with drone imaging data and portable apparatus analyses. Moreover, spectra of either drone imaging and portable apparatus showed clear differences between healthy and FD-infected grapevines, validating multispectral/ hyperspectral technology as a potential tool for the early detection of FD or other grapevine-associated diseases.

Climate ethnography and wine environmental futures

Globalisation and climate change have radically transformed world wine production upsetting the established order of wine ecologies. Ecological risks and the future of traditional agricultural systems are widely debated in anthropology, but very little is understood of the particular challenges posed by climate change to viticulture which is seen by many as the canary in the coalmine of global agriculture. Moreover, wine as a globalised embedded commodity provides a particularly telling example for the study of climate change having already attracted early scientific attention. Studies of climate change in viticulture have focused primarily on the production of systematic models of adaptation and vulnerability, while the human and cultural factors, which are key to adaptation and sustainable futures, are largely missing. Climate experts have been unanimous in recognising the urgent need for a better understanding of the complex dynamics that shape how climate change is experienced and responded to by human systems. Yet this call has not yet been addressed. Climate ethnography, coined by the anthropologist Susan Crate (2011), aims to bridge this growing disjuncture between climate science and everyday life through the exploration of the social meaning of climate change. It seeks to investigate the confrontation of its social salience in different locations and under different environmental guises (Goodman 2018: 340). By understanding how wine producers make sense of the world (and the environment) and act in it, it proposes to focus on the co-production of interdisciplinary knowledge by identifying and foreshadowing problems (Goodman 2018: 342; Goodman & Marshall 2018). It seeks to offer an original, transformative and contrasted perspective to climate change scenarios by investigating human agency -individual or collective- in all its social, political and cultural diversity. An anthropological approach founded on detailed ethnographies of wine production is ideally placed to address economic, social and cultural disruptions caused by the emergence of these new environmental challenges. Indeed, the community of experts in environmental change have recently called for research that will encompass the human dimension and for more broad-based, integrated through interdisciplinarity, useful knowledge (Castree & al 2014). My paper seeks to engage with climate ethnography and discuss what it brings to the study of wine environmental futures while exploring the limitations of the anthropological environmental approach.