Search results for "Penicillium expansum"
showing 10 items of 23 documents
Caractères moisi-terreux des vins : origine et prévention
2005
Note de synthèse du groupe national de travail ONIVINS - juillet 2005; National audience
Biopreservation of tomatoes using fermented media by lactic acid bacteria
2020
Abstract Post-harvest spoilage fungi in tomatoes represent an economic loss for industry and consumers. There is currently an increasing demand for novel applications of bio-preservatives as replacers of chemical additives and pesticides in food. In this study, nine lactic acid bacteria strains isolated from tomato and sourdough were screened for antifungal activity in vitro against 33 fungal strains and used as bio-preservatives of tomato inoculated with Penicillium expansum and Aspergillus flavus. The identification of the compounds potentially responsible for the antifungal activity, such as organic acids, phenolic acids and volatile organic compounds (VOCs), were identified and quantifi…
Influence of temperature, copper and CO2on spore counts and geosmin production byPenicillium expansum
2012
Background and Aim: Musts and wines produced from rotten grapes often have an earthy/musty odour, with geosmin the responsible compound. Penicillium expansum is considered a potential source of geosmin in rotten grapes from vineyards treated with copper-based fungicides. Methods and Results: The laboratory study assessed the influence of temperature (10‐30°C), copper concentration (0‐76.50 mg/L) and CO 2 in the headspace (0.03‐3%) on the spore count and the production of geosmin by P. expansum according to a Doehlert design. The spore count and the production of geosmin (ng/mg biomass) were significantly correlated (r = 0.78). Copper had no significant effect on the spore count but was the …
Apple (Malus domestica) and Tomato (Lycopersicum esculentum) Fruits Cell-Wall Hemicelluloses and Xyloglucan Degradation during Penicillium expansum I…
2004
We characterized the changes in cell-wall hemicellulosic polysaccharides and the hemicellulose-degrading enzymes associated with apple and tomato fruits infected by Penicillium expansum. Our results showed a reduction in the molecular mass of hemicelluloses, with this reduction being particularly notable in the xyloglucan associated with P. expansum infection. The activation of fungal beta-glucanases was also highlighted. Fruit xyloglucan endotransglucosylase/hydrolase (XTH)-specific activity decreased drastically during the infection process in both apple and tomato fruits. We suggest that XTH reduction during the infection might be related with the fungus attack mechanism. We also suggest…
Le goût moisi-terreux du vin : contribution à la caractérisation cinétique et métabolique des moisissures associées à ce défaut organoleptique
2011
Some microorganisms that co-exist on the grapevine may have beneficial effects on the quality of wine whereas others may be at the origin of organoleptic deviations. In the last decade, several mouldy or earthy odors have been highlighted in various wine regions from France. (-)-geosmin was found to be the major compound responsible for this deviation, along with Botrytis cinerea and fungi belonging to the genus Penicillium, since they were frequently isolated from “earthy-musty” odor grapes. The extent of damage on the quality of wines, motivated our study on the caracterisation of grape rot fungi. First of all, the microflora of grapes from Burgundy vineyards was identified (morphological…
Lag time for germination of Penicillium chrysogenum conidia is induced by temperature shifts.
2013
In the environment, fungal conidia are subject to transient conditions. In particular, temperature is varying according to day/night periods. All predictive models for germination assume that fungal spores can adapt instantaneously to changes of temperature. The only study that supports this assumption (Gougouli and Koutsoumanis, 2012, Modelling germination of fungal spores at constant and fluctuating temperature conditions. International Journal of Food Microbiology, 152: 153-161) was carried out on Penicillium expansum and Aspergillus niger conidia that, in most cases, already produced germ tubes. In contrast, the present study focuses on temperature shifts applied during the first stages…
In vitro antifungal activity of allyl isothiocyanate (AITC) against Aspergillus parasiticus and Penicillium expansum and evaluation of the AITC estim…
2015
Abstract Isothiocyanates (ITCs) are natural compounds derived from cruciferous vegetables produced by enzymatic conversion of metabolites called glucosinolates. They are potentially useful antimicrobial compounds for food applications have been shown to be promising agents against cancer in human cell culture, animal models, and in epidemiological studies. In this study, the antifungal activity of the allyl isothiocyanate (AITC) was evaluated on two mycotoxigenic fungi as Aspergillus parasiticus and Penicillium expnsum , aflatoxins (AFs) and patulin (PAT) producers, employing an assay on solid medium. Also an approximation of the risk evaluation associated to the intake of food treated with…
Validation of a predictive model for the growth of Botrytis cinerea and Penicillium expansum on grape berries.
2010
The objective of this study was to develop and to validate a model for predicting the combined effect of temperature and a(w) on the radial growth rate, mu, of Botrytis cinerea and Penicillium expansum on grape berries. The proposed strategy was based on the gamma-concept developed previously [Zwietering, M.H., Wijtzes, T., de Wit, J.C., van't Riet, K. 1992. A decision support system for prediction of the microbial spoilage in foods. Journal of Food Protection. 12, 973-979]: mu=mu(opt).gamma(T).gamma(a(w)), where the gamma functions were cardinal models with inflection (CMI), mu(opt) the radial growth rate on grape berries. Firstly, the cardinal temperatures and a(w)'s were estimated indepe…
Antimicrobial packaging based on ɛ-polylysine bioactive film for the control of mycotoxigenic fungi in vitro and in bread
2017
Abstract ɛ‐Poly‐l‐lysine (ɛ‐PL) is a cationic peptide with a broad‐spectrum antimicrobial activity. This study investigates the use of ɛ‐PL as natural antimicrobial to inhibit fungal growth and to reduce aflatoxins (AFs) production. Antifungal activity of starch biofilms with different concentrations of ɛ‐Poly‐l‐lysine (ɛ‐PL) was determined in solid medium against Aspergillus parasiticus (AFs producer) and Penicillium expansum. Then, biofilms were tested as antimicrobial devices for the preservation of bread loaf inoculated with A. parasiticus CECT 2681 and P. expansum CECT 2278. Shelf life and AFs content were examined. Biofilms with concentrations of ɛ‐PL less than 1.6 mg/cm2 showed no fu…
Changes in cell wall pectin and pectinase activity in apple and tomato fruits duringPenicillium expansum infection
2006
Cell wall pectin degradation in apple and tomato fruit during infection by Penicillium expansum was investigated. In infected apple fruit, a significant decrease in the average molecular mass was observed in pectins extracted with CDTA and also in pectins extracted with Na2CO3. In tomato fruits, depolymerisation was also observed in both pectic fractions during infection, the major change being in the pectins extracted with Na2CO3. This pectin depolymerisation associated with P. expansum infection can be attributed to the action of pectinases; in apple fruit, a significant increase in polygalacturonase and pectin methylesterase was observed in infected fruits, although in tomato fruit the o…