terclim by ICS banner
IVES 9 IVES Conference Series 9 International Congress on Grapevine and Wine Sciences 9 2ICGWS-2023 9 Effect of ultraviolet B radiation on pathogenic molds of grapes

Effect of ultraviolet B radiation on pathogenic molds of grapes

Abstract

The fungicidal effect of UV-C radiation (100-280 nm wavelength) is well known, but its applicability for the control of pathogenic molds of grapes is conditioned by its effect on the host and by the risks inherent in its handling[1]

As an alternative, the effect in vitro of UV-B radiation (280-315 nm) on the main pathogenic molds of grapes has been studied: Botrytis cinerea, Aspergillus niger, Penicillium expansum and Rhizopus stolonifer.

The molds studied were seeded on Czapek agar plates (in triplicate) that were irradiated with UV-B radiation lamps located at a height of 25 cm, obtaining an irradiance of 16 Wm-2. Different exposure times (0, 1, 3, 6, 12 and 24 hours) were applied on two series of plates. One of the series was protected from radiation by UV radiation filters and acted as a control. After exposure, the plates were incubated at 20ºC in the darkness, assessing the degree of mold development over two weeks.

UV-B radiation caused a clear inhibitory effect on the development of the molds studied that was proportional to the irradiation dose received. The observed effect was different for each mold, being Rhizopus stolonipher and Botrytis cinerea the most sensitive to UV-B radiation. The resistance of molds to UV-B radiation has been related by different authors with mold pigmentation[2].

These results allow us to contemplate the use of UV-B radiation in the control of pathogenic molds of grapes.

References:

1)  Usall J. et al. (2016) Physical treatments to control postharvest diseases of fresh fruits and vegetables. Post. Biol. Tech., 122: 30-40, DOI 10.1016/j.postharvbio.2016.05.002

2)  García-Cela, M.E. et al. (2016) Conidia survival of Aspergillus section Nigri, Flavi and Circumdati under UV-A and UV-B radiation with cycling temperature/light regime. J. Sci. Food Agric., 96:2249-2256, DOI 10.1002/jsfa.734

DOI:

Publication date: October 6, 2023

Issue: ICGWS 2023

Type: Poster

Authors

Hidalgo-Sanz R., Del-Castillo-Alonso M.A., Sanz S., Olarte C., Martínez-Abaigar J., Núñez-Olivera E.

Faculty of Science and Technology, University of La Rioja. 26006 Logroño (La Rioja), Spain

Contact the author*

Keywords

UVR-B, pathogens molds, grapes

Tags

2ICGWS | ICGWS | ICGWS 2023 | IVES Conference Series

Citation

Related articles…

A sensometabolomic approach to understand wine mouthfeel percepts

Targeted analytical methods can overlook compounds that are a priori unknown to play a role in the mouthfeel sensations. This limitation can be overcome with the information provided by untargeted metabolomic analysis using UPLC‐QTOF-MS. To this end, an untargeted metabolomic approach applied to 42 red wines has allowed development of a model with predictive capacity by cross-validation for the “dry”, “oily” and “unctuous” sensations perceived by a sensory panel. The optimal PLS model for “dry” retained compounds with positive regression coefficients (≥ 0.17) including a trimer procyanidin, a peptide, and four anthocyanins.

Barrels ad-hoc: Spanish oak wood classification by NIRs 

The wooden barrel is a key factor in enology, since wine chemical composition and sensory properties changes significantly in contact with the barrel[1]. Today’s highly competitive market constantly demands new differentiated products and wineries search innovations continuously.
Wood selection is crucial: barrels stability to keep constant their contribution and the result on products, and additional and differentiated wood contributions to impact their new products. Oak wood selection has traditionally been carried out using parameters such as specie, location and grain, however, it goes one step further nowadays. Large cooperage work with non-destructive techniques that allow classifying oak wood quickly and easily according to their organoleptic contribution[2].

Preliminary results of water status and metabolite content of three new crossbreed winegrape genotypes

This study presents the preliminary results obtained in 2022, of the evaluation of three new crossbreed winegrape genotypes and their parental varieties, grown under controlled irrigation (60% ETc) and rainfed conditions in a wine-growing area with scarcity of water and high temperatures (Murcia, southeast Spain). The genotypes MC16 and MC80 were obtained from crosses between the varieties ‘Monastrell’ and ‘Cabernet Sauvignon’, and MS104 from crosses between ‘Monastrell’ and ‘Syrah’ [1]. The objective of this study was to analyse the physiological response and vegetative development of the 6 genotypes under the two irrigation conditions, and to study their effect on the content of soluble sugars and chlorophyll in the leaf.

Yeast mannoprotein characterization and their effect on Oenococcus oeni and malolactic fermentation

Mannoproteins are released at the end of alcoholic fermentation due to yeast autolysis [1]. It has been described a positive effect of these molecules on lactic acid bacteria growth [2]. The main objective of this work was the characterization of different mannoproteins extracted from active dry yeast (ADY) and the assessment of their effect on Oenococcus oeni and malolactic fermentation (MLF).

Wine racking in the winery and the use of inerting gases

The O2 uptake in the different winemaking processes is generally considered to be negative for the sensory characteristics of white and rosé wines. Wine racking is a critical point of O2 uptake, as the large surface area of the wine exposed during this operation and the inability to maintain an effective inert gas blanket over it.
The objective was to study O2 uptake during the racking of a model wine without using inert gases and to compare it with the purging of the destination tank with different inert gases.