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IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Skin And Seed Extracts Differently Behave Towards Salivary Proteins

Skin And Seed Extracts Differently Behave Towards Salivary Proteins

Abstract

Background: 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 skin/seed ratios, as detailed below: A (ratio 2:1 skin : seed), B(ratio 1:1 skin : seed) and C (ratio 1:2 skin: seed).

Methods: 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), which measures the reactivity of salivary proteins towards wine polyphenols.

Results: The results obtained in this experiment highlighted important differences in the behavior of the samples as a function of the different skin:seed ratio. When skins and seeds  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.

Conclusion:

Results of our study highlighted not only the important role of the skin:seed ratio in regulating 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 24, 2022

Issue: IVAS 2022

Type: Poster

Authors

Errichiello Francesco1, Guerriero Antonio1, Picariello Luigi1, Coppola Francesca1, Rinaldi Alessandra1,2, Forino Martino1 and Gambuti Angelita1

1Department of Agricultural Sciences, Grape and Wine Science Division, University of Naples Federico II
2Biolaffort, 126 Quai de la Souys, 33100 Bordeaux, France

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Keywords

skin/seed extract; anthocyanins; polymeric pigments; astringency.

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IVAS 2022 | IVES Conference Series

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Use of multispectral satellite for monitoring vine water status in mediterranean areas

The development of new generations of multispectral satellites such as Sentinel-2 opens possibilities as to vine water status assessment (Cohen et al., 2019). Based on a three years field campaign, a model of Stem Water Potential (SWP) estimation on vine using four satellite bands in Red, Red-Edge, NIR and SWIR domains was developed (Laroche-Pinel et al., 2021). The model relies on SWP field measures done using a pressure chamber (Scholander et al., 1965), which is a common, robust and precise method to assess vine water status (Acevedo-Opazo et al., 2008). The model was mainly developed from from SWP measures on Syrah N (Laroche Pinel E., 2021).

A large scale monitoring was organized in different vineyards in the Mediterranean region in 2021. 10 varieties amongst the most represented in this area were monitored (Cabernet sauvignon N, Chardonnay B, Cinsault N, Grenache N, Merlot N, Mourvèdre N, Sauvignon B, Syrah N, Vermentino B, Viognier B). The model was used to produce water status maps from Sentinel-2 images, starting from the beginning of June (fruit set) up to September (harvest). The average estimated SWP for each vine was compared to actual field SWP measures done by wine growers or technicians during usual monitoring of irrigation programs. The correlations between mean estimated SWP and mean measured SWP were at the same level than expected by the model. (Laroche Pinel, 2021) The general SWP kinetics were comparable. The estimated SWP would have led to same irrigation decisions concerning the date of first irrigation in comparison with measured SWP.

Acevedo-Opazo, C., Tisseyre, B., Ojeda, H., Ortega-Farias, S., Guillaume, S. (2008). Is it possible to assess the spatial variability of vine water status? OENO One, 42(4), 203.
Cohen, Y., Gogumalla, P., Bahat, I., Netzer, Y., Ben-Gal, A., Lenski, I., … Helman, D. (2019). Can time series of multispectral satellite images be used to estimate stem water potential in vineyards? In Precision agriculture ’19, The Netherlands: Wageningen Academic Publishers, pp. 445–451.
Laroche-Pinel, E., Duthoit, S., Albughdadi, M., Costard, A. D., Rousseau, J., Chéret, V., & Clenet, H. (2021). Towards vine water status monitoring on a large scale using sentinel-2 images. remote sensing, 13(9), 1837.
Laroche-Pinel,E. (2021). Suivi du statut hydrique de la vigne par télédétection hyper et multispectrale. Thèse INP Toulouse, France.
Scholander, P.F., Bradstreet, E.D., Hemmingsen, E.A., & Hammel, H.T. (1965). Sap pressure in vascular plants: Negative hydrostatic pressure can be measured in plants. Science, 148(3668), 339–346.

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IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Skin And Seed Extracts Differently Behave Towards Salivary Proteins

Skin And Seed Extracts Differently Behave Towards Salivary Proteins

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Publication date: June 24, 2022

Issue: IVAS 2022

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