terclim by ICS banner
IVES 9 IVES Conference Series 9 EFFECT OF DIFFERENT TEMPERATURE AND WATER-LOSS DEHYDRATION CONDITIONS ON THE PATTERN OF FREE AND GLYCOSYLATED VOLATILE METABOLITES OF ITALIAN RED GRAPES

EFFECT OF DIFFERENT TEMPERATURE AND WATER-LOSS DEHYDRATION CONDITIONS ON THE PATTERN OF FREE AND GLYCOSYLATED VOLATILE METABOLITES OF ITALIAN RED GRAPES

Abstract

Post-harvest grape berries dehydration/withering are worldwide applied to produce high-quality sweet and dry wines (e.i., Vin Santo, Tokaji, Amarone della Valpolicella). Temperature and water loss impact grape metabolism [1] and are key variables in modulating the production of grape compounds of oenological interest, such as Volatile Organic Compounds (VOCs), secondary metabolites responsible for the aroma of the final wine.

The aim of this research was to assess the impact of post-harvest dehydration on free and glycosylated VOCs of two Italian red wine grapes, namely Nebbiolo and Aleatico, dehydrated in tunnel under controlled condition (varied temperature and weight-loss, at constant humidity and air flow). From these grapes Sforzato di Valtellina Passito DOCG and Elba Aleatico Passito DOCG, respectively.

The experimental plan followed a “Temperature (10°C, 15°C, 20°C, 25°C) x Weight loss (0%, 10%, 20%, 30%)” factorial design. Skin and juice free and glycosylated VOCs of grape berries were separately analysed by Solid Phase Extraction/Gas Chromatography–Mass Spectrometry (SPE/GC-MS) [2].

Results showed that skin and juice samples are well discriminated in both varieties, with skins exhibiting a greater aromatic richness, especially in terms of bound VOCs. In Nebbiolo grapes, weight loss showed a greater influence than temperature on free volatiles. This trend was not observed on free VOCs of Aleatico grapes, that were treated with more stressful dehydration conditions of temperature (15°C, 25°C) and weight loss (20%, 30%) compared to Nebbiolo grapes (10°C, 20°C; 10%, 20%).

Temperature seems to play an important role on bound VOCs of both grapes, albeit in a different form. In Nebbiolo grapes, low temperatures (10°C) showed positive correlations with the accumulation of aroma glycosidic precursors. In the case of Aleatico, which is a semi-aromatic variety, dehydration temperatures, appear to modulate terpenes pattern regardless of weight loss. Specifically, samples dehydrated at 15°C correlated with betalinalool, epoxylinalool, cis- and trans-linalool oxide, and geranic acid, while 25°C ones with cis- and trans-geraniol, cis- and trans-citral, α-terpineol, and citronellol.

These results are of interest for optimizing the grape dehydration process not only in an optic of management of product characteristics and varietal oenology, but also in a prospective of management of energy resources needed under controlled dehydration conditions.

 

1. Costantini et al., 2006. DOI: 10.1021/jf053117l
2. Piombino et al., 2022. DOI: 10.1111/ajgw.12521

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Article

Authors

Paola Piombino1, Elisabetta Pittari1, Alessandro Genovese2, Andrea Bellincontro3, Fabio Mencarelli4, Luigi Moio1

1. Department of Agricultural Sciences, Division of Vine and Wine Sciences, University of Naples Federico II, Avellino 83100, Italy
2. Department of Agricultural Sciences, Division of Food Science and Technology, University of Naples Federico II, Portici (NA), 80055, Italy
3. DIBAF, University of Tuscia, Via De Lellis, 01100 Viterbo, Italy
4. Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, Pisa 56124, Italy

Contact the author*

Keywords

grapes dehydration, secondary metabolites, aromas, SPE/GC-MS

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

Overhead spray water treatment as a mitigation strategy for reducing vine stress and preserving grape quality during heatwaves

Changes in climate have been influencing the quality of wine grapes worldwide. The impact of extreme climate events over short periods is increasingly recognized as a serious risk to grape quality and yield quantity. In this study the mitigation effects of a pulsed water spray on vine canopy during heatwave events has been evaluated for maintaining vine condition during the growing season and grape quality. Vines of three varieties (Malbec, Bonarda, and Syrah) under drip irrigation in the UNCuyo experimental vineyard were treated with an overhead pulsed water spray.

INVESTIGATION OF FILM COATINGS AS A PROTECTIVE LAYER IN REDUCING THE ABSORPTION OF SMOKE PHENOLS INTO PINOT NOIR GRAPES

Wine grapes exposed to wildfire smoke have resulted in wines with burnt and ashy sensory characteristics¹, that are undesirable qualities in wine. In extreme wildfire events, this can lead to total loss of grape crop. Currently there are no effective solutions in the market to prevent the uptake of smoke compounds into grapes. In this study, previously developed innovative film coatings were tested to analyze their effectiveness in reducing smoke phenol absorption². Four different cellulose nanofiber-based film types were investigated.

MONITOR SOME KEY PARAMETERS THROUGH THE IMPLEMENTATION OFCONTINUOUS CONTROL SYSTEMS OF THE MUST-WINE DURING MACERATION-FERMENTATION IN RED WINEMAKING TO MANAGE OPERATIONS IN “AUTOMATION”

This study is aimed to develop a complete tool for the winemaker with, complete and targeted “winemaking recipes” that can be adapted to criteria set by the winemaker, such as: grape variety, grape health status, degree of ripening, desired wine, redox status throughout the alcoholic fermentation.
To get such aim, specific sets of experiments using red grape juices from different varieties (Nebbiolo, Barbera, Pinot noir, etc.) collected at different technological and phenolic maturity points, will be held with “automatized 4.0 tanks” equipped with sensors for measuring: redox potential, dissolved oxygen, relative density, temperature, and color in order to collect a sufficient amount of data preparatory to the creation of operating models in the most widely winemaking situations in which the automatized 4.0 tanks “will be able to independently respond” with the right corrective actions (opening/closing aeration valve, execution/block pumping overs , etc.) if the key parameters exceed the limits of the recommended ranges set in the selected recipe.

EFFECT OF FERMENTATION TEMPERATURE GRADIENT AND SKIN CONTACT ON ESTER AND THIOL PRODUCTION AND TROPICAL FRUIT PERCEPTION IN CHARDONNAY WINES

Wines with tropical fruit aromas have become increasingly more available1,2. With increased availability of different wine styles, it has become important to understand the compounds that cause the fruity aromas in wine. Previous work using micro fermentations showed that fermentation temperature gradients and time on skins resulted in an increase in thiol and ester compounds post fermentation and these compounds are known to cause tropical fruit aroma in wines³. This work aimed to scale up these fermentations/operations to determine if the desired aromas could still be achieved and if there is a perceivable difference in tropical fruit aromas, liking, and emotional response in the wines at the consumer level.

Influence of agrophotovoltaic on vine and must in a cool climate

The current energy crisis means that interest in agrophotovoltaics has increased significantly. The reason behind this is that the system aims to combine agricultural production with energy production. During the three-year period from 2020 to 2022, the effects of photovoltaic panels on the vine, the yield and the quality of the must were studied in Walenstadt in northern Switzerland, an area with a cool, humid climate. 65 Pinot noir vines were planted in the 160m2 study area. Because of the large edge effects, only 3 repetitions with 4 vines each could be created. A significantly lower leaf infestation by Plasmopara viticola was observed among the panels in each of the three years.