Search results for "Food spoilage"
showing 10 items of 90 documents
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…
Starter cultures as biocontrol strategy to prevent Brettanomyces bruxellensis proliferation in wine
2017
Brettanomyces bruxellensis is a common and significant wine spoilage microorganism. B. bruxellensis strains generally detain the molecular basis to produce compounds that are detrimental for the organoleptic quality of the wine, including some classes of volatile phenols that derive from the sequential bioconversion of specific hydroxycinnamic acids such as ferulate and p-coumarate. Although B. bruxellensis can be detected at any stage of the winemaking process, it is typically isolated at the end of the alcoholic fermentation (AF), before the staring of the spontaneous malolactic fermentation (MLF) or during barrel aging. For this reason, the endemic diffusion of B. bruxellensis leads to c…
A concept of mould spoilage prevention and acrylamide reduction in wheat bread: application of lactobacilli in combination with a cranberry coating
2018
In this study, a concept for wheat bread moulding prevention and acrylamide reduction has been developed. It includes various lactic acid bacteria (LAB), selected according to their technological, antifungal and acrylamide-lowering properties, in combination with an antifungal cranberry coating for wheat bread surface treatment. All the tested strains (Pediococcus pentosaceus LUHS183, Pediococcus acidilactici LUHS29, Lactobacillus paracasei LUHS244, Lactobacillus brevis LUHS173, Lactobacillus plantarum LUHS135 and Leuconostoc mesenteroides LUHS242) showed antifungal activities against Aspergillus nidulans, Penicillium funiculosum and Fusarium poae. However, L. brevis LUHS173 and Leu. mesent…
Native Vineyard Non-Saccharomyces Yeasts Used for Biological Control of Botrytis cinerea in Stored Table Grape
2021
Postharvest spoilage fungi, such as Botrytis cinerea, are considered the main cause of losses of fresh fruit quality and vegetables during storage, distribution, and consumption. The current control strategy is the use of SO2 generator pads whose application is now largely under observation. A high quantity of SO2 can be deleterious for fresh fruits and vegetables and it is not allowed in organic agriculture. For this reason, great attention has been recently focused on identifying Biological Control Agents (BCA) to implement biological approaches devoid of chemicals. In this direction, we carried out our study in isolating five different non-Saccharomyces yeast strains from local vineyards…
Design and Performance Testing of a DNA Extraction Assay for Sensitive and Reliable Quantification of Acetic Acid Bacteria Directly in Red Wine Using…
2016
International audience; Although strategies exist to prevent AAB contamination, the increased interest for wines with low sulfite addition leads to greater AAB spoilage. Hence, there is a real need for a rapid, specific, sensitive, and reliable method for detecting these spoilage bacteria. All these requirements are met by real time Polymerase Chain Reaction (or quantitative PCR; qPCR). Here, we compare existing methods of isolating DNA and their adaptation to a red wine matrix. Two different protocols for isolating DNA and three PCR mix compositions were tested to select the best method. The addition of insoluble polyvinylpolypyrrolidone (PVPP) at 1% (v/v) during DNA extraction using a pro…
Use of autochthonous yeasts and bacteria in order to control Brettanomyces bruxellensis in wine
2017
Biocontrol strategies for the limitation of undesired microbial developments in foods and beverages represent a keystone toward the goal of more sustainable food systems. Brettanomyces bruxellensis is a wine spoilage microorganism that produces several compounds that are detrimental for the organoleptic quality of the wine, including some classes of volatile phenols. To control the proliferation of this yeast, sulfur dioxide is commonly employed, but the efficiency of this compound depends on the B. bruxellensis strain; and it is subject to wine composition and may induce the entrance in a viable, but nonculturable state of yeasts. Moreover, it can also elicit allergic reactions in humans. …
Devices containing allyl isothiocyanate against the growth of spoilage and mycotoxigenic fungi in mozzarella cheese
2018
Filter paper and stickers containing allyl isothiocyanate (AIT), as well as pouches containing mustard meal and water for intrinsic production of AIT, were tested against aflatoxigenic strains of Penicillium digitatum CECT 2954 and Aspergillus parasiticus CECT 2681 in sliced mozzarella. Slices were inoculated with either fungus, packaged in plastic bags or plastic trays with one antimicrobial device (2–16 µL/L of AIT). Control groups presented visual growth of P. digitatum after 19.0 ± 1.5 d in bags and 26.1 ± 2.1 d in trays. A. parasiticus was visually detectable after 41.4 ± 1.7 d and 28.4 ± 1.5 d in trays and bags, respectively. AIT‐treated samples did not present visual fungal growth fo…
Modelling the effect of temperature, pH, water activity, and organic acids on the germination time of Penicillium camemberti and Penicillium roquefor…
2017
International audience; In this study, the influence of environmental factors on the germination time of Penicillium camemberti and Penicillium roqueforti conidia was evaluated. To do so, the effects of i/temperature, pH, water activity, and ii/organic acids were determined using models based on i/cardinal values, and ii/minimum inhibitory concentration (MIC) respectively. Cardinal values for germination of conidia were not observed to be species dependent. Minimum temperatures were estimated to be below the freezing point, with an optimum of 26.9 degrees C, and a maximum of 33.5 degrees C. For both species, minimal and optimal a(w) values were found to be 0.83 and 0.99, respectively, while…
Effects of innovative and conventional sanitizing treatments on the reduction of Saccharomycopsis fibuligera defects on industrial durum wheat bread
2016
Wickerhamomyces anomalus, Hyphopichia burtonii and Saccharomycopsis fibuligera are spoilage yeasts causing chalk mold defects on sliced bread packaged under modified atmosphere. The first objective of this study, carried out in a bread-making company for two consecutive years, was to genetically identify yeasts isolated from spoiled sliced bread in Modified Atmosphere Packaging (MAP) and to determine the dominant species among identified strains. The second objective was to evaluate the effects of hydrogen peroxide and silver solution 12% (HPS) treatment in the leavening cells and cooling chambers, in comparison with the conventional Ortho-Phenylphenol (OPP) fumigating treatment, on the inc…
Improved detection and enumeration of yeasts in wine by Cells-qPCR
2018
Abstract Quantitative PCR by directly sampling (Cells-qPCR) has been adapted to detect and quantify total yeasts, and B. bruxellensis, S. cerevisiae and Z. bailii species, in grape musts and wines. To increase assay sensitivity, the effects of a previous cell wall lysis, by both enzymatic and mechanical methods, were evaluated. Cell wall disruption by mechanical methods showed the best results to enhance assay sensitivity. Numerous standard curves were constructed by mechanically lysed cells in culture medium, and in white and red grape musts and wines. Good regression values (>0.99) and efficiencies (>0.99) were obtained, and it was possible to detect one single cell per reaction in all th…