 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

Brown Marmorated Stink Bug taint in grape must and wine: time evolution of trans-2-decenal

The brown marmorated stink bug (BMSB, Halyomorpha halys Stal) is an invasive pentatomid native to eastern Asia that is spreading rapidly worldwide, notably through human-mediated activities. Globally, it was reported in the USA, Canada, Italy, Hungary, and other European countries. BMSB has a broad host range that includes over 170 plants, many of agricultural importance, including various fruit, vegetables, row crops, and ornamentals. When present in the vineyard, the pest can affect yield and quality by directly feeding on berries resulting in fruit collapse and necrosis. Additional damage occurs when BMSB are carried into the winery within the grape clusters. The presence of BMSB during wine processing can affect juice and wine quality through the release of volatile compounds produced as a stress response. The major secretes compounds are tridecane and trans-2-decenal. Tridecane is an odorless compound and its effect on wine quality is currently unknown. Trans-2-decenal is an unsaturated aldehyde considered to be the main component of BMSB taint with strong green, coriander, and musty-like aromas. Its threshold value in wine was estimated at about 5 µg/L.

Identification of QTLS for sunburn resilience in grapevine berries

Context and purpose of the study – Grape sunburn is an abiotic stress response triggered by high temperatures.

Effect of mannoproteins extracted from Torulaspora delbrueckii on wine flavanol composition and on flavanol-salivary protein interactions

Global climate change is exerting an influence on vine phenology, leading to a decoupling of technological and phenolic maturity of grapes. This results in the modification of berry chemical composition, which can translate into wines with excessive astringency. The addition of mannoproteins (MP) to wine has been proposed as a way of mitigating this problem, since some studies have shown that MPs can modulate wine astringency. However, the mechanism underlying the astringency modulation effect of MPs is not well known and it seems to be dependent on the compositional and structural characteristics of the MP.

Algae protein: fining agent for white wine, sustainable, non-allergenic and animal-free

The development of non-animal and non-allergenic alternatives to traditional protein fining agents used in winemaking is of critical importance in order to ensure consumer safety and production sustainability. This study evaluates the effect of protein extracted from three types of algae (spirulina, chlorella vulgaris and tetraselmis chuii) as fining agents on the polymeric proanthocyanidin content responsible for astringency, as well as their effect on the colour, phenolic composition and volatile aroma of two white wines (a and b).

LARGE SURVEY OF THE CHEMICAL COMPOSITION OF WINES RESULTING OF THE PRESSING OF RED WINE MARC. FIRST RESULTS

In the Bordeaux vineyards, press red wine represents about 15% of the volume of wines. Valuing this large volume of press wine is necessary from an economic point of view, of course, but also because of their organoleptic contribution to the blend. Nevertheless, there is a lack of recent knowledge on the composition of press wines. This work aims to establish an initial assessment of their composition (aromatic and polyphenolic) and to set up hypothesis on to the links with their sensorial identity.