 IVES 9 IVES Conference Series 9 Biosurfactant from corn-milling industry improves the release of phenolic compounds during red winemaking

Biosurfactant from corn-milling industry improves the release of phenolic compounds during red winemaking

Abstract

AIM: Biosurfactants can be used as emulsifier agents to improve the taste, flavour, and quality of food-products with minimal health hazards [1]. They are surface-active compounds with antioxidant and solubilizing properties [2]. In this study, a biosurfactant has been evaluated during red winemaking for its effect on fermentation dynamics, phenolic compounds extraction, and colour stabilization.

METHODS: The biosurfactant used was obtained from a fermented residual stream of corn-milling industry, named corn steep liquor (CSL). The harvested mass from Merlot winegrapes was distributed in 12 fermentation flaks with the same proportion of grape juice and solid parts. Six of them were added with CSL biosurfactant (1 g/L) whereas the other six were not added (control). Two fermentation protocols were assessed (spontaneous and Saccharomyces cerevisiae inoculated). Fermentation dynamics and kinetics, standard chemical parameters, colour characteristics, and phenolic composition were determined during maceration and at the end of malolactic fermentation.

RESULTS: During inoculated maceration, the biosurfactant-added samples showed significantly higher values of total polyphenols and colour intensity when compared to control, and lower ones of the three colour CIEL*a*b* coordinates (lightness, red/green, and yellow/blue). At the end of alcoholic fermentation, a higher percentage of more stable polymerized pigments was also observed. The final wine resulted to be richer in total polyphenols and anthocyanins, as well as in high molecular weight flavanols for the biosurfactant-added samples.

CONCLUSIONS

The biosurfactant addition did not affect negatively on inoculated fermentation dynamics and influenced positively the colour stability after malolactic fermentation resulting in darker and bluish wines. No significant changes on colour properties and related compounds were observed when spontaneous fermentation was performed.

ACKNOWLEDGMENTS

This study was supported by the Spanish Ministry of Economy and Competitiveness (MINECO project RTI2018-093610-B-100)

DOI:

Publication date: September 7, 2021

Issue: Macrowine 2021

Type: Article

Authors

Susana Río Segade

University of Torino, Italy,Susana RÍO SEGADE, University of Torino, Italy Vasileios ENGLEZOS, University of Torino, Italy Alejandro LÓPEZ-PRIETO, University of Vigo, Spain Maria Alessandra PAISSONI, University of Torino, Italy Simone GIACOSA, University of Torino, Italy Kalliopi RANTSIOU, University of Torino, Italy Luca ROLLE, University of Torino, Italy Benita PÉREZ CID, University of Vigo, Spain Ana Belén MOLDES, University of Vigo, Spain Jose Manuel CRUZ, University of Vigo, Spain

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Keywords

red grapes; winemaking; biosurfactant; fermentation dynamics; colour characteristics; phenolic compounds; polymeric pigments

Citation

Local adaptation tools to ensure the viticultural sustainability in a changing climate

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Geospatial trends of bioclimatic indexes in the topographically complex region of Barolo DOCG

Barolo DOCG is an economically important wine producing region in Northwest Italy. It is a small region of approximately 70 km2 gross area. The topography is very complex with steep sloped hills ranging in elevation from below 200 m to 550 m. Barolo DOCG wine is made exclusively from the Nebbiolo grape. Bioclimatic indexes are often used in viticulture to gain a better understanding of broader climate trends which can be compared temporally and geographically. These indexes are also used for identifying potential phenological timing, growing region suitability, and potential risks associated with expected climatic changes. Understanding how topography influences bioclimatic indexes can help with understanding of mesoscale climate behaviour leading to improved decision making and risk management strategies. The average monthly maximum and minimum temperatures, the Cool Night Index, the Huglin Index, and the monthly diurnal range (from July to October) were calculated using data from 45 weather stations within a 40 km radius of the Barolo DOCG growing area between the years 1996 and 2019. Linear and multiple regression models were developed using independent variables (elevation, aspect, slope) extracted from a digital elevation model to identify significant relationships. Bioclimatic indexes were then kriged with external drift using independent variables that showed significant relationships with the bioclimatic index using a 100 m resolution grid. The maximum monthly temperatures and the Huglin Index showed consistent significant negative relationships with elevation in all years. The minimum monthly temperatures showed no relationship with elevation but in some months a small but significant relationship was observed with aspect. Due to the lack of a relationship between minimum monthly temperatures and elevation compared to the significant relationship between maximum monthly temperatures and elevation, monthly diurnal range had a negative relationship with elevation.

Assessing the climate change vulnerability of European winegrowing regions by combining exposure, sensitivity and adaptive capacity indicators

Winegrowing regions recognized as protected designations of origin (PDOs) are closely tied to well defined geographic locations with a specific set of pedoclimatic attributes and strictly regulated by legal specifications. However, climate change is increasingly threatening these regions by changing local conditions and altering winegrowing processes. The vulnerability to these changes is largely heterogenous across different winegrowing regions because it is determined by individual characteristics of each region, including the capacity to adapt to new climatic conditions and the sensitivity to climate change, which depend not only on natural, but also socioeconomic and legal factors. Accurate vulnerability assessments therefore need to combine information about adaptive capacity and climate change sensitivity with projected exposure to new climatic conditions. However, most existing studies focus on specific impacts neglecting important interactions between the different factors that determine climate change vulnerability. Here, we present the first comprehensive vulnerability assessment of European wine PDOs that spatially combines multiple indicators of adaptive capacity and climate change sensitivity with high-resolution climate projections. We found that the climate change vulnerability of PDO areas largely depends on the complex interactions between physical and socioeconomic factors. Homogenous topographic conditions and a narrow varietal spectrum increase climate change vulnerability, while the skills and education of farmers, together with a good economic situation, decrease their vulnerability. Assessments of climate change consequences therefore need to consider multiple variables as well as their interrelations to provide a comprehensive understanding of the expected impacts of climate change on European PDOs. Our results provide the first vulnerability assessment for European winegrowing regions at high spatiotemporal resolution that includes multiple factors related to climate exposure, sensitivity, and adaptive capacity on the level of single winegrowing regions. They will therefore help to identify hot spots of climate change vulnerability among European PDOs and efficiently direct adaptation strategies.

A predictive model of spatial Eca variability in the vineyard to support the monitoring of plant status

Spatial determination of areas in the Western Balkans region favorable for organic production

In problematic conditions for production of grapes and wine caused by the COVID-19 pandemic and the resulting occurrence of wine surpluses, producers are increasingly turning to the innovative viticulture and winemaking of products that are more appealing to the market and the consumers. On the other hand, consumption of the food safety or organic products, and therefore of organic grapes and wine, is increasingly common in the world, in particular in Europe. The Regional Rural Development Standing Working Group (SWG RRD), as a regional intergovernmental organization gathers actors in the viticulture and winemaking sector from states and territories of the Western Balkans (South-East Europe) in the Expert Working Group for Wine, with the aim of improving viticulture and winemaking in this region through joint activities. In accordance with the aforementioned, the SWG RRD is working on advancing organic production of grapes and wine, and on recognition of specificities of the terroir of wine-growing areas in Western Balkans. In addition, as part of the project “Facilitation of Exchange and Advice on Wine Regulations in Western Balkan Countries” helmed by the German Federal Ministry of Food and Agriculture, in addition to harmonization of relevant legislation with EU regulations, efforts are being invested towards recognition of organic wines. Within activities and project implemented by this organization, expert analyses and scientific research of the terroir of Western Balkans were carried out, and some of the results are presented in this paper.