 IVES 9 IVES Conference Series 9 Ochratoxin a degradation by Botrytis cinerea laccase: effect of oenological factors and redox mediators

Ochratoxin a degradation by Botrytis cinerea laccase: effect of oenological factors and redox mediators

Abstract

AIM: This study evaluates the effect of different oenological factors and natural mediators on the degradation of Ochratoxin A (OTA) using Botrytis cinerea laccase. Because of its risk to human health, different detoxification techniques have been developed in various kinds of foodstuffs. The use of fungal or bacterial laccases is a biological method to decrease the OTA concentration [1, 2]. Laccases can oxidize a wide range of substrates, some of which cannot be oxidized directly by these enzymes and require the use of redox mediators [3]. Due to this, several natural mediators present in wine and different SO₂ and ethanol concentrations were tested in the current work.

METHODS: The ability of laccase to degrade OTA was studied by incubation of the enzyme in acetate buffer pH 4.0 and model wine, with OTA and mediators at 28 ºC during 24 h. To determine the impact of SO₂ and ethanol on the OTA degradation caused by laccase, different concentrations of SO₂ (10, 20 and 30 mg/L) and ethanol (5, 10 and 15% v/v) were used. The quantification of this mycotoxin was carried out in a HPLC-QTOF-MS system.

RESULTS: Under these conditions, OTA cannot be oxidized directly by laccase from Botrytis cinerea and the use of redox mediators is required. Among natural mediators tested, (-)-epicatechin and (+)-catechin were the phenolic compounds with higher impact on the biodegradation of this mycotoxin, achieving a decrease of OTA concentration over 50%. The degradation of OTA was completely inhibed by 30 mg of SO₂/L, while 20 mg of SO₂/L reduced lacasse activity by a half and 10 mg of SO₂/L hardly caused any effect on the biodegradation of this mycotoxin. A concentration of 15% of ethanol led to a 50% reduction in the activity of laccase over OTA.

CONCLUSIONS

These preliminary results may be a first step in finding biological alternative strategies to eliminate undesirable substances such as mycotoxins (OTA) present in wine.

DOI:

Publication date: September 14, 2021

Issue: Macrowine 2021

Type: Article

Authors

osé Pérez-Navarro

Regional Institute for Applied Scientific Research (IRICA), University of Castilla-La Mancha, Av. Camilo José Cela 10, 13071 Ciudad Real, Spain. Higher Technical School of Agronomic Engineering, University of Castilla-La Mancha, Ronda de Calatrava 7, 13071 Ciudad Real, Spain.,Tania, PANIAGUA MARTÍNEZ, Faculty of Chemical Sciences and Technologies, University of Castilla-La Mancha, Av. Camilo José Cela, 10, 13071 Ciudad Real, Spain. Pol, GIMÉNEZ, Faculty of Oenology, University of Rovira I Virgili, C/Marcel.li Domingo s/n, 43007 Tarragona, Spain. Joan Miquel, CANALS, Faculty of Oenology, University of Rovira I Virgili, C/Marcel.li Domingo s/n, 43007 Tarragona, Spain. Fernando, ZAMORA, Faculty of Oenology, University of Rovira I Virgili, C/Marcel.li Domingo s/n, 43007 Tarragona, Spain. Sergio, GÓMEZ-ALONSO, Regional Institute for Applied Scientific Research (IRICA), University of Castilla-La Mancha, Av. Camilo José Cela 10, 13071 Ciudad Real, Spain. Faculty of Chemical Sciences and Technologies, University of Castilla-La Mancha, Av. Camilo José Cela, 10, 13071 Ciudad Real, Spain.

Contact the author

Keywords

mycotoxin, enzyme, biodetoxification, fungi, SO₂, ethanol

Citation

Multidisciplinary assessment of selective harvesting in the Colli Piacentini wine district

Within-field variability can be managed through Precision Viticulture (PV) protocols aiming at identifying homogeneous zones and addressing site-specific operations including selective harvesting (SH). Several authors demonstrated SH profitability in extensive viticulture while few information is available within the Italian context.

To a better understanding of the impact of vine nitrogen status on volatile thiols from plot to transcriptome level

Volatile thiols contribute largely to the organoleptic characteristics and typicity of Sauvignon blanc wines. Among this family of odorous compounds, 3-sulfanylhexan-1-ol (3SH) and 4-methyl-4-sulfanylpentan-2-one (4MSP) have a major impact on wine flavor. These thiols are formed during alcoholic fermentation by the yeast from odorless and non-volatile precursors found in the berry and the must. The effect of vine nitrogen status on 3SH and 4MSP in Sauvignon blanc wine and on the glutathionylated and cysteinylated precursors of 3SH (Glut-3SH and Cys-3SH) was investigated in this study.

Intravarietal diversity: an opportunity for climate change adaptation

Merlot grapevine is the second wine cultivar most planted in the world and especially in the Bordeaux wine region. This cultivar has many advantages in producing high quality wine; however, in the last decade, climate change has increased the sugar concentration in berries at harvest and shortened the maturation cycle. If this has been up to now a great opportunity to improve wine quality profile, we are touching the tipping point. High sugar concentration at harvest induces high alcool content in wine which can negatively impact wine quality. There are many viticultural and oenological practices possible to limit this effect. In this study we focus on plant material through intra-varietal diversity of Merlot cultivar.

Cytochrome P450 CYP71BE5 from grapevine (Vitis vinifera) catalyzes the formation of the spicy aroma compound, (-)-rotundone

(-)-Rotundone, an oxygenated sesquiterpene, is a potent odorant molecule with a characteristic spicy aroma existing in various plants including grapes1. It is considered as a significant compound notably in wines and grapes because of its low sensory threshold (16 ng L-1 in red wine, 8 ng L-1 in water) and aroma properties. (-)-Rotundone was first identified in red wine made from the grape cultivar Syrah (regionally called Shiraz) in Australia1, and then it was found in several grape varieties such as Duras, Grüner Veltliner, Schioppettino and Vespolina from Europe2, 3. Several environmental factors affecting the accumulation of (-)-Rotundone during the grape maturation, were reported such as ambient temperature4, soil properties and topography5, soil moisture from irrigation and light exposure in the bunch zone by leaf removal2.

Detection of spider mite using artificial intelligence in digital viticulture

Aim: Pests have a high impact on yield and grape quality in viticulture. An objective and rapid detection of pests under field conditions is needed. New sensing technologies and artificial intelligence could be used for pests detection in digital viticulture. The aim of this work was to apply computer vision and deep learning techniques for automatic detection of spider mite symptoms in grapevine under field conditions.