terclim by ICS banner
IVES 9 IVES Conference Series 9 FREE TERPENE RESPONSE OF ‘MOSCATO BIANCO’ VARIETY TO GRAPE COLD STORAGE

FREE TERPENE RESPONSE OF ‘MOSCATO BIANCO’ VARIETY TO GRAPE COLD STORAGE

Abstract

Temperature control is crucial in wine production, starting from grape harvest to the bottled wine storage. Climate change and global warming affect the timing of grape ripening, and harvesting is often done during hot summer days, influencing berry integrity, secondary metabolites potential, enzyme and oxidation phenomena, and even fermentation kinetics. To curb this phenomenon, pre-fermentative cold storage can help preserve the grapes and possibly increase the concentration of key secondary metabolites.

In this study, the effect of grape pre-fermentative cold storage was assessed on the ‘Moscato bianco’ white grape cultivar, known for its varietal terpenes (65% of free terpenes represented by linalool and its derivatives) and widely used in Piedmont (Italy) to produce Asti DOCG wines. The study involved two experiments: a 12 h short-term storage under fresh (15 °C) and sunny outdoor (peak of 43 °C) conditions, and a medium-term storage under five different temperatures (5, 7, 12, 17, 19 °C) and durations (12, 24, 54, 84, 96 h), according to a Central Composite Design then evaluated using response-surface methodology (RSM). Berry skin break force mechanical property and juice physiochemical parameters were analyzed, as well as juice free terpene compounds using GC-MS.

In the short-term trial, after 4 and 8 h of storage the cooled sample showed a higher concentration of linalool, but at the end of the storage (12 h, when external temperature dropped to 25-20 °C after sunset), an opposite situation was found, possibly indicating a higher terpene solubilization in their thermotolerance defense role.

The medium-storage experiment indicated that the sum of the 13 detected terpenes in grape juice significantly decreased progressively after 75 h of storage, particularly in samples stored at the highest temperature tested (19 °C). However, the RSM model indicates that storage times shorter than 50 h contributed to higher terpenes, as well as the increase in storage temperature. The berry skin break force was not affected significantly by the treatments.

In conclusion, grape cold storage may offer several advantages in winemaking, but further studies are needed on this variety for assessing the best storage temperature and length conditions, as well as for the comparison between free and glycosidically-bound terpenes in juice and in the resulting wine. Acknowledgments. We thank Marco Rossetto and DENSO Thermal Systems (Poirino, Italy) for their support to this study.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Simone Giacosa¹, Stefania Savoi¹, Annachiara Lenti¹, Susana Río Segade¹, Maria Alessandra Paissoni¹, Andrea Bellincontro², Fabio Mencarelli³, Luca Rolle¹

1. University of Torino, Department of Agricultural, Forest and Food Sciences. Corso Enotria 2/C, 12051 Alba (CN), Italy
2. University of Tuscia, Department for Innovation in Biological, Agro-food and Forest systems. Via San Camillo de Lellis snc, Viterbo, Italy
3. University of Pisa, Department of Agriculture, Food and Environment. Via del Borghetto 80, Pisa, Italy

Contact the author*

Keywords

grape cold storage, aroma, terpenes, Muscat varieties

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

HOW OXYGEN CONSUMPTION INFLUENCES RED WINES VOLTAMMETRIC PROFILE

Phenolic compounds play a central role in sensory characteristics of wine, such as colour, mouthfeel, flavour and determine its shelf life. Furthermore, the major non-enzymatic wine oxidation process is due to the catalytic oxidation of phenols in quinones. Due their importance, during the years have been developed different analytical methods to monitor the concentration of phenols in wine, such as Folin-Ciocalteu method, spectrophotometric techniques and HPLC. These methods can also be used to follow some oxidation-related chemical transformations.

THE FLAVANOL PROFILE OF SKIN, SEED, WINES, AND POMACE ARE CHARACTERISTIC OF EACH TYPOLOGY AND CONTRIBUTES TO UNDERSTAND THE FLAVAN- 3-OLS EXTRACTION DURING RED WINEMAKING

Wine flavanols are extracted from grape skin and seeds along red winemaking. Potentially, eight flavan-3-ol subunits may be present as monomers or as tannins constituents, being these catechin, epicathechin, gallocatechin, epigallocatechin end the gallates of the mentioned units. In this work the flavanol profiles of grape skins and seeds before (grapes) and after (pomace) red winemaking were studied together with the one in the corresponding wines. The trials were made over two vintages in Vitis vinifera cv. Tannat, Syrah and Marselan from Uruguay.

THE IMPACT OF NON-SACCHAROMYCES YEASTS ON THE WHITE WINE QUALITY

Selected strains of non-Saccharomyces yeasts showed a positive effect on sensory characteristics and aromatic complexity of wine. A sequential microbial culture of non-Saccharomyces and S. cerevisiae species is usually inoculated due to poorer fermentability of non-Saccharomyces species. The aim of the study was to investigate the role of non-Saccharomyces yeasts in the production of white wines. We evaluated how individual combinations of sequential inoculations of non-Saccharomyces and S. cerevisiae species affect the aromatic compounds (volatile thiols and esters) and sensory characteristics of the wines.

IMPACT OF MUST NITROGEN DEFICIENCY ON WHITE WINE COMPOSITION DEPENDING ON GRAPE VARIETY

Nitrogen (N) nutrition of the vineyard strongly influences the must and the wine compositions. Several chemical markers present in wine (i.e., proline, succinic acid, higher alcohols and phenolic compounds) have been proposed for the cultivar Chasselas, as indicators of N deficiency in the grape must at harvest [1]. Grape genetics potentially influences the impact of N deficiency on grape composition, as well as on the concentration of potential indicators in the wine. The goal of this study was to evaluate if the che- mical markers found in Chasselas wine can be extended for other white wines to indicate N deficiency in the grape must.

CONTRIBUTION OF VOLATILE THIOLS TO THE AROMA OF RIESLING WINES FROM THREE REGIONS IN GERMANY AND FRANCE (RHEINGAU, MOSEL, AND ALSACE)

Riesling wines are appreciated for their diverse aromas, ranging from the fruity fresh characters in young vintages to the fragrant empyreumatic notes developed with aging. Wine tasters often refer to Riesling wines as prime examples showcasing terroir, with their typical aroma profiles reflecting the geographical provenance of the wine. However, the molecular basis of the distinctive aromas of these varietal wines from major Riesling producing regions in Europe have not been fully elucidated. In this study, new lights were shed on the chemical characterization and the sensory contribution of volatile thiols to Riesling wines from Rheingau, Mosel, and Alsace. First, Riesling wines (n = 46) from the three regions were collected and assessed for their aroma typicality by an expert panel.