Macrowine 2021
IVES 9 IVES Conference Series 9 Microbial stabilization of wines using innovative coiled UV-C reactor process: impact on chemical and organoleptic proprieties

Microbial stabilization of wines using innovative coiled UV-C reactor process: impact on chemical and organoleptic proprieties


For several years, numerous studies aimed at limiting the use of SO2 in wines (thermal treatments, pulsed electric fields, microwaves …). Processes must be able to preserve the organoleptic qualities of wines with low energy consumption. In this context, ultraviolet radiations (UV-C), at 254 nm, are well known for their germicidal proprieties. In order to inactivate microorganisms in grape juice and wine without affecting the quality of the product, efficiency of UV-C treatment process should be optimized. Indeed, previous studies show a great efficiency for low absorbing liquids, but a poor one for high absorbing liquids, due to the lack of UV penetration. For this purpose, coiled tube UV-C reactor has been used in this study. The main component of this reactor is a FEP tube, helically wound around the UV lamp quartz sleeve. Dean vortices (radial flows) generated in this coiled tube reduce the UV dose (in J/L) required, ensuring a homogeneous dose distribution in absorbing liquids. UV-C dose was evaluated by actinometric measurments using iodide/iodate actinometry, allowing us to select the most suitable flow rate. The inactivation performance of this process on multiple strains (S.cerevisiae, D.bruxellensis diploid and triploid, and O.oeni) and the impact of UV-C treatment on sensorial, physicochemical proprieties and chemical compounds like thiols, were investigated on white and rosé wine. The entire continuous process has been evaluated in lab and semi-industrial scale at 2 hL/h. UV-C doses required to achieve a 6 log10 microbial reduction are low (less than 600J/L) in white and rosé wine. Sensorial and physicochemical analyses, after treatment and after three months, didn’t show differences between treated and untreated wines. Chemicals compounds quantification and sensorial analyses on red wine are currently in progress.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster


Rémy Junqua*, Cécile Thibon, Emmanuel Vinsonneau, Marta Avramova, Martine Mietton-Peuchot, Pons Alexandre, Remy Ghidossi


Contact the author


IVES Conference Series | Macrowine | Macrowine 2016


Related articles…

New molecular evidence of wine yeast-bacteria interaction unraveled by untargeted metabolomic profiling

Bacterial malolactic fermentation (MLF) has a considerable impact on wine quality. The yeast strain used for primary fermentation can consistently stimulate (MLF+ phenotype) or inhibit (MLF- phenotype) malolactic bacteria and the MLF process as a function of numerous winemaking practices, but the molecular evidence behind still remains a mystery. In this study, such evidence was elucidated by the direct comparison of extracellular metabolic profiles of MLF+ and MLF- yeast phenotypes. Untargeted metabolomics combining ultrahigh-resolution FT-ICR-MS analysis, powerful machine learning methods and a comprehensive wine metabolite database, discovered around 800 putative biomarkers and 2500 unknown masses involved in phenotypic distinction.

The challenge of quality in sulphur dioxide free wines: natural polyphenol alternatives

Sulphur dioxide (SO2) seems indispensable in winemaking because of its properties. However, a current increasing concern about its allergies effects in food product has addressed the international research efforts on its replacement. This supposes a sufficient knowledge of its properties and conditions of use. Several studies compared SO2 properties against new alternatives that are supposed to overcome SO2 disadvantages. Firstly, the state of art on SO2 wine replacements is revised, and secondly, the last promising results using natural enriched polyphenol extracts are shown.

Oxygen consumption by diferent oenological tanins in a model wine solution

INTRODUCTION: Oenological tannins are widely used in winemaking to improve some characteristics of wines [1] being the antioxidant properties probably one of the main reasons [2]. However, commercial tannins have different botanical sources and chemical composition [3] which probably determines different antioxidant potential. There are some few references about the antioxidant properties of commercial tannins [4] but none of them have really measured the direct oxygen consumption by them. The aim of this work was to measure the kinetics of oxygen consumption by different commercial tannins in order to determine their real capacities to protect wine against oxygen. MATERIAL AND METHODS: 4 different commercial tannins were used: T1: condensed tannin from grape seeds, T2: gallotannin from chinese gallnuts, T3: ellagitannin from oak and T4: tannin from quebracho containing condensed tannins and ellagitannins.

Effect of ageing with Specific Inactivated Dry Yeasts on the volatile composition of Sauvignon Blanc and Carménère wines

Úbeda-Aguilera, C a, b, Peña-Neira, A.b Del Barrio-Galán, R.b, c a Biomedical Sciences Institute, Science Faculty, Universidad Autónoma de Chile, Chile. b Department of Agro-Industry and Enology, Faculty of Agronomical Sciences, University of Chile, Post Office Box 1004, Santa Rosa 11315, La Pintana, Santiago, Chile c Lallemand Inc. Chile y Compañía Limitada, Rosario Norte 407, piso 6, Las Condes, Santiago, Chile The wine is a complex matrix made up of several compounds which can interact among themselves throughout the wine ageing process, thereby modifying their sensorial characteristics. It is well known that during ageing of wines on lees, polysaccharides (mainly mannoproteins) can be released and can interact with the aromatic fraction modifying its volatility.

Oenological features of Sangiovese wine from vinification of whole grape berries

The present study was performed in a traditional winery located in the viticultural area of Brunello di Montalcino, Siena, Italy, in the vintage 2015. Actually, in this winery Sangiovese grape musts are fermented in large oak barrels by a single strain of Saccharomyces cerevisiae previously isolated in the same winery. Pumping over operations are carried out once or twice a day until the end of alcoholic fermentations. The aim of this work was to investigate on the oenological properties of Sangiovese wine produced with the traditional winemaking process adopted by the winery under study obtained from the fermentation of whole berries compared to that from crushed grape must. In particular, two lots of 65q of Sangiovese grapes from the same 3ha vineyard were vinified in 150hL oak barrels.