IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Use of a recombinant protein (Harpin αβ) as a tool to improve phenolic composition in wines

Use of a recombinant protein (Harpin αβ) as a tool to improve phenolic composition in wines

Abstract

Climate change is modifying environmental conditions in all wine-growing areas of the world. High temperatures are the cause of an increased imbalance between industrial maturity and phenolic maturity, resulting in berries with high sugar levels, low concentration in organic acids and reduced concentrations in aromas and phenolic compounds. These grapes produce wines with high alcohol content and lack freshness, color intensity, and aromatic complexity. Viticultural strategies have been developed in recent years in order to maintain the quality of red wines, with a two-fold objective: improve the phenolic composition of wines and reduce their alcoholic content. Harpin αβ is a recombinant protein and elicitor of hypersensitive responses. When Harpin αβ is applied to crops, the expression of growth and defense genes is stimulated. These genes are generally associated with metabolic signals and pathways related to functions of protein and sugar transport and vegetative development. The objective of this work has been to apply Harpin αβ to the vines after veraison in order to advance harvest for reducing the alcohol content of the final wines while maintaining or improving their phenolic composition compared to full maturity grapes. This experiment was carried out in a commercial vineyard sited in Jumilla (Spain). Three treatments were applied; i) Control: untreated application of Harpin harvested at 15º Baume, ii) 2T: grapes treated twice with Harpin, at the time of veraison and 15 days later and harvested at 13º Baume and iii) 3T: an extra application of the compound made 15 days after the second treatment and grapes were also harvested at 13º Baume. In each treatment, the dose of Harpin αβ applied was 150 g/ha. All treatments were vinified in the same way. Once the wines were bottled, the physicochemical and chromatic parameters were analyzed. Wines from grapes of 2T treatments harvested at 13º Baume decrease significantly the pH, color intensity and total phenolic index of the wines. No significant difference was observed in the total acidity parameter. On the other hand, 3T treatmen increased significantly total anthocyanins compare to control wines. Moreover, this treatment obtained the highest concentration of tannins, although these differences were not significant compared to the control treatment. It is clear that the 3T treatment was much more effective in improving the phenolic concentration of the wines than the 2T treatment. These results showed that the Harpin application in the vineyard (3T) produced wines with similar phenolic content that the wines produced from fully ripe grapes but with 20% less alcohol. This makes the use of Harpin αβ an interesting strategy for winemakers seeking a natural reduction of alcoholic content in their wines without losing quality.

DOI:

Publication date: June 24, 2022

Issue: IVAS 2022

Type: Poster

Authors

Martínez-Moreno Alejandro ¹, Martínez-Pérez Pilar ¹, Bautista-Ortin Ana Belén¹ Pérez-Porras Paula¹ and Gomez-Plaza Encarna ¹

¹Department of Food Science and Technology, Faculty of Veterinary Sciences, University of Murcia

Contact the author

Keywords

climate change, elicitors, grape ripening, alcohol

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Copper contamination in vineyard soils of Bordeaux: spatial risk assessment for the replanting of vines and crops

Copper (Cu) is widely and historically used in viticulture as a fungicide against mildew. Cu has a strong affinity for soil organic matter and accumulates in topsoil horizons. Thus, Cu may negatively affect soil organisms and plants, consequently reducing soil fertility and productivity. The Bordeaux vineyards have the largest vineyard surfaces (26%) within French controlled appellation and a great proportion of French wine production (around 5 million hl per year). Considering the local context of vineyard surfaces decreasing (vine uprooting) and possible new crop plantation, the issue of Cu potential toxicity rises. Therefore, the aims of this work are firstly to evaluate the Cu contamination in vineyard soils of Bordeaux, secondly to produce a risk assessment map for new vine or crop plantation. We used soil analyses from several local studies to build a database with 4496 soil horizon samples. The database was enhanced by means of pedotransfer functions in order to estimate the bioaccessible (EDTA-extractable) Cu in soils of samples without measurements. From this database, 1797 georeferenced samples with CuEDTA concentrations in the topsoil (0-50 cm depth) were used for kriging interpolation in order to produce the spatial distribution map of CuEDTA in vineyard soils. Then, the spatial distribution of Cu was crossed with vine uprooting surfaces and municipality boundaries. CuEDTAconcentrations ranged from 0.52 to 459 mg/kg and showed clear anomalies. Our results from spatial analysis showed that almost 50% of vineyard soil surfaces have CuEDTA concentrations higher than 30 mg/kg (moderate risk for new plantation) and 20% with concentrations higher than 50 mg/kg (high risk for new plantation). A decision-support map based on municipalities was realised to provide a simple tool to stakeholders concerned by land use management.

Underpinning terroir with data: rethinking the zoning paradigm

Agriculture, natural resource management and the production and sale of products such as wine are increasingly data-driven activities. Thus, the use of remote and proximal crop and soil sensors to aid management decisions is becoming commonplace and ‘Agtech’ is proliferating commercially; mapping, underpinned by geographical information systems and complex methods of spatial analysis, is widely used. Likewise, the chemical and sensory analysis of wines draws on multivariate statistics; the efficient winery intake of grapes, subsequent production of wines and their delivery to markets relies on logistics; whilst the sales and marketing of wines is increasingly driven by artificial intelligence linked to the recorded purchasing behaviour of consumers. In brief, there is data everywhere!

Opinions will vary on whether these developments are a good thing. Those concerned with the ‘mystique’ of wine, or the historical aspects of terroir and its preservation, may find them confronting. In contrast, they offer an opportunity to those interested in the biophysical elements of terroir, and efforts aimed at better understanding how these impact on vineyard performance and the sensory attributes of resultant wines. At the previous Terroir Congress, we demonstrated the potential of analytical methods used at the within-vineyard scale in the development of Precision Viticulture, in contributing to a quantitative understanding of regional terroir. For this conference, we take this approach forward with examples from contrasting locations in both the northern and southern hemispheres. We show how, by focussing on the vineyards within winegrowing regions, as opposed to all of the land within those regions, we might move towards a more robust terroir zoning than one derived from a mixture of history, thematic mapping, heuristics and the whims of marketers. Aside from providing improved understanding by underpinning terroir with data, such methods should also promote improved management of the entire wine value chain.

Mesoclimate impact on Tannat in the Atlantic terroir of Uruguay

The study of climate is relevant as an element conditioning the typicity of a product, its quality and sustainability over the years. The grapevine development and growth and the final grape and wine composition are closely related to temperature, while climate components vary at mesoscale according to topography and/or proximity to large bodies of water. The objective of this work is to assess the mesoclimate of the Atlantic region of Uruguay and to determine the effect of topography and the ocean on temperature and consequently on Tannat grapevine behavior.

VINIoT: Precision viticulture service for SMEs based on IoT sensors network

The main innovation in the VINIoT service is the joint use of two technologies that are currently used separately: vineyard monitoring using multispectral imaging and deployed terrain sensors. One part of the system is based on the development of artificial intelligence algorithms that are feed on the images of the multispectral camera and IoT sensors, high-level information on water stress, grape ripening status and the presence of diseases. In order to obtain algorithms to determine the state of ripening of the grapes and avoid losing information due to the diversity of the grape berries, it was decided to work along the first year 2020 at berry scale in the laboratory, during the second year at the cluster scale and on the last year at plot scale. Different varieties of white and red grapes were used; in the case of Galicia we worked with the white grape variety Treixadura and the red variety Mencía. During the 2020 and 2021 campaigns, multispectral images were taken in the visible and infrared range of: 1) sets of 100 grapes classifying them by means of densimetric baths, 2) individual bunches. The images taken with the laboratory analysis of the ripening stage were correlated. Technological maturity, pH, probable degree, malic acid content, tartaric acid content and parameters for assessing phenolic maturity, IPT, anthocyanin content were determined. It has been calculated for each single image the mean value of each spectral band (only taking into account the pixels of interest) and a correlation study of these values with laboratory data has been carried out. These studies are still provisional and it will be necessary to continue with them, jointly with the training of the machine learning algorithms. Processed data will allow to determine the sensitivity of the multispectral images and select bands of interest in maturation.

Adaptation to soil and climate through the choice of plant material

Choosing the rootstock, the scion variety and the training system best suited to the local soil and climate are the key elements for an economically sustainable production of wine. The choice of the rootstock/scion variety best adapted to the characteristics of the soil is essential but, by changing climatic conditions, ongoing climate change disrupts the fine-tuned local equilibrium. Higher temperatures induce shifts in developmental stages, with on the one hand increasing fears of spring frost damages and, on the other hand, ripening during the warmest periods in summer. Expected higher water demand and longer and more frequent drought events are also major concerns. The genetic control of the phenotypes, by genomic information but also by the epigenetic control of gene expression, offers a lot of opportunities for adapting the plant material to the future. For complex traits, genomic selection is also a promising method for predicting phenotypes. However, ecophysiological modelling is necessary to better anticipate the phenotypes in unexplored climatic conditions Genetic approaches applied on parameters of ecophysiological models rather than raw observed data are more than ever the basis for finding, or building, the ideal varieties of the future.