Macrowine 2021
IVES 9 IVES Conference Series 9 Microwave-assisted maceration and stems addition in Bonarda grapes: effects on wine chemical composition and sensory properties over two vintages

Microwave-assisted maceration and stems addition in Bonarda grapes: effects on wine chemical composition and sensory properties over two vintages

Abstract

AIM: Bonarda, the second red grape variety in Argentina, produces high yields per hectare generating, in several cases, wines with low levels of quality compounds. Microwave-assisted extraction (MW) is a novel extraction technique for winemaking, widely applied in other foods. Stems addition (S) during vinification can be a sustainable technology for phenolic and aroma contribution without additional cost. Therefore, this study aimed to evaluate the combined effect of MW application with stem additions in different conditions, before fermentation, on the chemical composition and sensory properties of Bonarda wines.

METHODS: During two consecutive vintages (2018-2019), 450 kg of grapes were harvested (≈24°Brix) from a commercial vineyard (Mendoza, Argentina), and made into wine in 25 L following a standard protocol. The experimental design consisted of ten treatments (two factors) by triplicate. Two maceration strategies were applied [control (C), and microwaved-assisted extraction after grape crushing (MW; 2450 MHz, 7600 W, 45-50°C)], combined with five stem-contact conditions [control without stems (WS), 50% stems addition (S50), 50% stems addition + MW of the stems (S50MW; 2450 MHz, 7600 W, 60°C), 100% stems addition (S100), 100% stems addition + MW (S100MW)]. Wines were analyzed for basic chemistry (1), phenolic composition and color parameters (2-5), polysaccharides (6), and aroma profiles (7). Additionally, a descriptive sensory analysis (QDA) was performed with 19 panelists in 8 sessions, and 22 attributes were established.

RESULTS: In both seasons, the application of microwaves significantly reduced microbial flora in musts (fungi, yeasts, and acetic acid bacteria), in addition to inhibiting enzymatic activity (cellulase and pectinase). Due to the significant difference of the vintage and its interaction with some of the studied factors, the chemical and sensory characterization of wines were evaluated separately for each season. The 2018 wines showed higher pH with stem additions and MW application in both matrices. Stem additions increased tannin content by 63% (S100) and by >35% for the other treatments; while MW consistently improved phenolic extraction (mainly, anthocyanins and derivatives), and polymeric pigments formation. Likewise, combined strategies increased polysaccharides extraction (FI, 165 kDa; FII, 45 kDa; FIII, 12 kDa), enhanced wine color (greater saturation), and intensified violet hue. Finally, the PCA including sensory variables described the MWS50 wines with higher color intensity and chocolate aroma, and 100% stems addition treatments with more astringency and violet hue. The behavior observed in 2019 was similar, with a more marked effect of MW on wine color (C*ab and polymeric pigments).

CONCLUSIONS:

The reported results are promising and are considered the first advance in the knowledge of the impact of the proposed technological strategies on the chemical and sensory quality of red wines.

DOI:

Publication date: September 7, 2021

Issue: Macrowine 2021

Type: Article

Authors

Martín Fanzone 

Estación Experimental Mendoza, Instituto Nacional de Tecnología Agropecuaria, San Martín 3853, M5528AHB, Luján de Cuyo, Mendoza, Argentina. Universidad Juan Agustín Maza, Av. Acceso Este Lateral Sur 2245, CP5519, Guaymallén, Mendoza, Argentina.,Ignacio Coronado. Estación Experimental Mendoza, Instituto Nacional de Tecnología Agropecuaria, San Martín 3853, M5528AHB, Luján de Cuyo, Mendoza, Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina. Santiago Sari. Estación Experimental Mendoza, Instituto Nacional de Tecnología Agropecuaria, San Martín 3853, M5528AHB, Luján de Cuyo, Mendoza, Argentina. Anibal Catania. Estación Experimental Mendoza, Instituto Nacional de Tecnología Agropecuaria, San Martín 3853, M5528AHB, Luján de Cuyo, Mendoza, Argentina. Mariona Gil i Cortiella. Instituto de Ciencias Químicas Aplicadas, Universidad Autónoma de Chile, Santiago 8910060, Chile. Cristina Ubeda. Departamento de Nutrición y Bromatología, Toxicología y Medicina Legal, Facultad de Farmacia, Universidad de Sevilla, C/Profesor García González 2, 41012 Sevilla, Spain. Instituto de Ciencias Biomédicas, Facultad de Ciencias, Universidad Autónoma de Chile, Santiago 8910060, Chile. Mariela Assof. Estación Experimental Mendoza, Instituto Nacional de Tecnología Agropecuaria, San Martín 3853, M5528AHB, Luján de Cuyo, Mendoza, Argentina. Universidad Juan Agustín Maza, Av. Acceso Este Lateral Sur 2245, CP5519, Guaymallén, Mendoza, Argentina. Viviana Jofré. Estación Experimental Mendoza, Instituto Nacional de Tecnología Agropecuaria, San Martín 3853, M5528AHB, Luján de Cuyo, Mendoza, Argentina. Universidad Juan Agustín Maza, Av. Acceso Este Lateral Sur 2245, CP5519, Guaymallén, Mendoza, Argentina. Vilma Morata de Ambrosini. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina. Facultad de Ciencias Aplicadas a la Industria, Universidad Nacional de Cuyo, Bernardo de Irigoyen 375, 5600, Mendoza, Argentina. Alvaro Peña Neira. Facultad de Ciencias Agronómicas, Universidad de Chile, Avenida Santa Rosa 11315, Santiago 8820808, Chile.

Contact the author

Keywords

microwave-assisted extraction, stems, bonarda, phenolics, polysaccharides, aromas, sensory analysis

Citation

Related articles…

Impact of geographical location on the phenolic profile of minority varieties grown in Spain. II: red grapevines

Because terroir and cultivar are drivers of wine quality, is essential to investigate theirs effects on polyphenolic profile before promoting the implantation of a red minority variety in a specific area. This work, included in MINORVIN project, focuses in the polyphenolic profile of 7 red grapevines minority varieties of Vitis vinifera L. (Morate, Sanguina, Santafe, Terriza Tinta Jeromo Tortozona Tinta) and Tempranillo) from six typical viticulture Spanish areas: Aragón (A1), Cataluña (A2), Castilla la Mancha (A3), Castilla –León (A4), Madrid (A5) and Navarra (A6) of 2020 season. Polyphenolic substances were extracted from grapes. 35 compounds were identified and quantified (mg subtance/kg fresh berry) by HPLC and grouped in anthocyanins (ANT) flavanols (FLAVA), flavonols (FLAVO), hydroxycinnamic (AH), benzoic (BA) acids and stilbenes (ST). Antioxidant activity (AA, mmol TE /g fresh berry) was determined by DPPH method. The results were submitted to a two-way ANOVA to investigate the influence of variety, area and their interaction for each polyphenolic family and cluster analysis was used to construct hierarchical dendrograms, searching the natural groupings among the samples. Sanguina (A3) had the most of total polyphenols while Tempranillo (A5) those of ANT. Sanguina (A2) and (A3) reached the highest values of FLAVO, FLAVA and AA. These two last samples had also the maximum of AA. The effect cultivar and area were significant for all polyphenolic families analyzed. A high variability due to variety (>50%) was observed in FLAVA and the maximum value of variability due to growing area was detected in AA (86.41%), ANT and FLAVO (51%); the interaction variety*zone was significant only for ANT, FLAVO, EST and AA. Finally, dendrograms presented five cluster: i) Sanguina (A2); ii) Sanguina (A3); iii) Tempranillo (A5); iv) Tempranillo (A3); Terriza (A3,A5), Morate (A5,A6); v) Santafé (A1,A6); Tortozona tinta (A1,A3,A6); Tinta Jeromo (A3,A4).

Modeling island and coastal vineyards potential in the context of climate change

Climate change impacts regional and local climates, which in turn affects the world’s wine regions. In the short term, these modifications rises issues about maintaining quality and style of wine, and in a longer term about the suitability of grape varieties and the sustainability of traditional wine regions. Thus, adaptation to climate change represents a major challenge for viticulture. In this context, island and coastal vineyards could become coveted areas due to their specific climatic conditions. In regions subject to warming, the proximity of the sea can moderate extremes temperatures, which could be an advantage for wine. However, coastal and island areas are particular prized spaces and subject to multiple pressures that make the establishment or extension of viticulture complex.
In this perspective, it seems relevant to assess the potentialities of coastal and island areas for viticulture. This contribution will present a spatial optimization model that tends to characterize most suitable agroclimatic patterns in historical or emerging vineyards according to different scenarios. Thanks to an in-depth bibliography a global inventory of coastal and insular vineyards on a worldwide scale has been realized. Relevant criteria have been identified to describe the specificities of these vineyards. They are used as input data in the optimization process, which will optimize some objectives and spatial aspects. According to a predefined scenario, the objectives are set in three main categories associated with climatic characteristics, vineyards characteristics and management strategies. At the end of this optimization process, a series of maps presents the different spatial configurations that maximize the scenario objectives.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares

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.

The impact of sustainable management regimes on amino acid profiles in grape juice, grape skin flavonoids, and hydroxycinnamic acids

One of the biggest challenges of agriculture today is maintaining food safety and food quality while providing ecosystem services such as biodiversity conservation, pest and disease control, ensuring water quality and supply, and climate regulation. Organic farming was shown to promote biodiversity and carbon sequestration, and is therefore seen as one possibility of environmentally friendly production. Consumers expect organically grown crops to be free from chemical pesticides and mineral fertilizers and often presume that the quality of organically grown crops is different or higher compared to conventionally grown crops. Integrated, organic, and biodynamic viticulture were compared in a replicated field trial in Geisenheim, Germany (Vitis vinifera L. cv. Riesling). Amino acid profiles in juice, grape skin flavonoids, and hydroxycinnamic acids were monitored over three consecutive seasons beginning 7 years after conversion to organic and biodynamic viticulture, respectively. In addition, parameters such as soil nutrient status, yield, vigor, canopy temperature, and water stress were monitored to draw conclusions on reasons for the observed changes. Results revealed that the different sustainable management regimes highly differed in their amino acid profiles in juice and also in their skin flavonol content, whereas differences in the flavanol and hydroxycinnamic acid content were less pronounced. It is very likely that differences in nutrient status and yield determined amino acid profiles in juice, although all three systems showed similar amounts of mineralized nitrogen in the soil. Canopy structure and temperature in the bunch zone did not differ among treatments and therefore cannot account for the observed differences in favonols. A different light exposure of the bunches in the respective systems due to differences in vigor together with differences in berry size and a different water status of the vines might rather be responsible for the increase in flavonol content under organic and biodynamic viticulture.