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…

Current climate change in the Oplenac wine-growing district (Serbia)

Serbian autochthonous vine varieties Smederevka (for white wines) and Prokupac (for rosé and red wines) are the primary representatives of typical characteristics of wines and terroir of numerous wine-growing areas in Serbia. In the past, these varieties were the leading vine varieties, however, as the result of globalization of winemaking and the trend of consumption of wines from widely prevalent vine varieties, they were replaced by introduced international varieties. Smederevka and Prokupac vine varieties are characterized by later time of grape ripening, and relative sensitivity to low temperatures. Climate conditions can be a restrictive factor for production of high-quality grapes and wine and for the spatial spreading of these varieties in hilly continental wine-growing areas.
This paper focuses on the spatial analysis of changes of main climate parameters, in particular, analysis of viticultural bioclimatic indices that were determined for the purposes of viticulture zoning of wine-growing areas in the period 1961-2010, and those same parameters determined for the current, that is, referential climate period (1988-2017). Results of the research, that is, analysis of climate changes indicate that the majority of examined climate parameters in the Oplenac wine-growing district improved from the perspective of Smederevka and Prokupac vine varieties. These studies of climate conditions indicate that changes of analyzed climate parameters, that is, bioclimatic indices will be favorable for cultivation of varieties with later grape ripening times and those more sensitive to low temperatures, such as the autochthonous vine varieties Smederevka and Prokupac, therefore, it is recommended to producers to more actively plant vineyards with these varieties in the territory of the Oplenac wine-growing district.

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

Impact of changes in pruning practices on vine growth and yield

A gradual decline in vineyards has been observed over the past twenty years worldwide. This might be explained by the climate change, practices change or the increase of dieback diseases. To increase the longevity of vines, we studied the impact of different pruning strategies in four adult and four young vineyards located in France and Spain. In France, vineyards were planted with Cabernet franc on 3309C while Spanish trials were planted with Tempranillo grafted on 110R. Vegetative expression, yield, quality of berries and wood vessels conductivity were measured. The distribution of vegetative expression, yield and berry composition between primary and secondary vegetation were quantified. Finally, tomography was used to evaluate the implication of the treatments on sap flows.
First results show that i) the respectful pruning leads to an increase of 30 to 50% more secondary shoots than the aggressive pruning in France and between 15 and 20% in Spain, ii) there is no major effect on the yield over the first two years following the implementation of the new pruning practices, although the proportion of clusters from suckers is higher on the respectful pruning method. On young vines, the development of the trunk according to a respectful pruning leads to a loss of harvest 2 years after planting. This is due to the removal, on the future trunk, of the green suckers which carrying bunches. This operation carried out in spring rather than during winter pruning, would promote a better leaf / fruit balance when the plant comes into production, and could lead to better hydraulic conduction in the vessels of the trunk. Maintaining these trials for several years will provide more robust data to assess the impact of these practices on the vines over the long term.

Effects of organic mulches on the soil environment and yield of grapevine

Farming management practices aiming at conserving soil moisture have been developed in arid and semiarid-areas facing water scarcity problems. Organic mulching is an effective method to manipulate the crop-growing microclimate increasing crop yield by controlling soil temperature, and retaining soil moisture by reducing soil evaporation. In this sense, the effectiveness of different organic mulching materials (straw mulch and grapevine pruning debris) applied within the row of a vineyard was evaluated on the soil and on the vine in a Tempranillo vineyard located in La Rioja (Spain). Organic mulches were compared with a traditional bare soil management technique (based on the use of herbicides to avoid weed incidence). Mulching coverages favourably influenced the soil water retention throughout all the grapevine vegetative cycle. However, the soil-moisture variation was not the same under different mulching materials, being the straw mulch (SM) the one that retained more water in comparison with grapevine pruning debris (GPD) based-cover. The changes of soil moisture in the upper surface layer (0–10 cm) were highly dynamic, probably due to water vapour fluxes across the soil-atmospheric interface. However, both, SM and GPD reduced these fluctuations as compared with bare soils. A similar trend occurred with soil temperature. Both organic mulches altered soil temperature in comparison with bare soil by reducing soil temperature in summer and raising it in winter. Moreover, the same buffering effect for the temperature on the covered soil also remains in the deeper layers. To conclude, we could see that organic mulching had a positive impact on soil-moisture storage and soil temperature and the extent of this effect depends on the type of mulching materials. These changes led to higher rates of photosynthesis and stomatal conductivity compared to bare soils, also favouring crop growth and grape yields.

Mapping and tracking canopy size with VitiCanopy

Understanding vineyard variability to target management strategies, apply inputs efficiently and deliver consistent grape quality to the winery is essential. However, despite inherent vineyard variability, the majority are managed as if they are uniform. VitiCanopy is a simple, grower-friendly tool for precision/digital viticulture that allows users to collect and interpret objective spatial information about vineyard performance. After four years of field and market research, an upgraded VitiCanopy has been created to achieve a more streamlined, technology-assisted vine monitoring tool that provides users with a set of superior new features, which could significantly improve the way users monitor their grapevines. These new features include:
• New user interface
• User authentication
• Batch analysis of multiple images
• Ease the learning curve through enhanced help features
• Reporting via the creation of colour maps that will allow users to assess the spatial differences in canopies within a vineyard.
Use-case examples are presented to demonstrate the quantification and mapping of vineyard variability through objective canopy measurements, ground-truthing of remotely sensed measurements, monitoring of crop conditions, implementation of disease and water management decisions as well as creating a history of each site to forecast quality. This intelligent tool allows users to manage grapevines and make informed management choices to achieve the desired production targets and remain profitable.