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The objective of this study was to evaluate a water‐soluble extract from sourdoughs fermented with the lactic acid bacteria (LAB) for antifungal reflect on loaf bread. The extracts produced by Lactobacillus plantarum CECT 749 and L. bulgaricus CECT 4005 were effective against strains of Fusarium spp., Penicillium spp., and Aspergillus spp., with minimum inhibitory concentration ranging from 1.6 to 200 mg/ml and minimum fungicidal concentration from 1.6 to 400 mg/ml. LC‐ESI‐MS‐TOF was used to analyze the antimicrobial compounds. Several antimicrobial phenolic acids were found. Fermented sourdoughs used for the production of loaf bread produced a reduction of fungal growth in relation on the sourdough control and improved to the shelf life of 1 to 2 days compared to control bread with 0.2% calcium propionate. Therefore, LAB are an alternative to synthetic compounds for decreasing fungal contaminants and prolonging the shelf life of food. Practical applications This study presents the importance of sourdough fermented by Lactobacillus plantarum spp. and the production during the fermentation of bioactive metabolites with antifungal activity. When applied in the preparation of bread, it is able to increase the useful life of the bread and its efficiency can be compared to that of calcium propionate. It is thus an alternative to synthetic compounds for decreasing fungal contaminants and prolonging the shelf life of food.

Fungal spoilage is one of the main reasons of economic losses in the food industry, especially in the wine sector. Consequently, the search for safer and new preservation techniques has gained importance in recent years. The objective of this study was to investigate the antifungal and anti-mycotoxigenic activity from 28 microorganisms (MO) isolated from red grape. The antifungal activity of a cell free supernatant of fermented medium by the isolated MO (CFS) was tested with the agar diffusion method and the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) assay. Additionally, different antifungal compounds from the CFS were identified and quantified (organic acids, phenolic compounds, and volatile organic compounds). Finally, the most active CFS were tested as red grape bio-preservative agents. Results evidenced that CFS fermented by the strain UTA 6 had the highest antifungal activity, above all isolates, and produced a wide pool of antifungal compounds. The use of UTA 6 CFS as bio-preservative agent showed a reduction of 0.4 and 0.6 log10 spores per gram of fruit in grapes contaminated by A. flavus and B. cinerea, respectively. Moreover, UTA 6 CFS treatment reduced the occurrence of aflatoxin B1 and fumonisin (B2, B3, and B4) production in grapes contaminated by 28–100%.

BACKGROUND: Filamentous fungi are the main contamination agent in the viticultural sector. Use of synthetic fungicides is the regular answer to these contaminations. Nevertheless, because of several problems associated with the use of synthetic compounds, the industry demands new and safer methods. In the present work, the biopreservation potential of four lactic acid bacteria (LAB) strains was studied against the principal grape contaminant fungi.RESULTS: Agar diffusion test evidenced that all four culture-free supernatant (CFS) had antifungal properties against all tested fungi. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) test values evidenced that media fermented by the Lactobacillus plantarum E3 and Lactobacillus plantarum E4 strains showed the highest antifungal activity, resulting in an MFC from 6.3 to 100 g L −1 . Analysis of CFS evidenced the presence of different antifungal compounds, such as lactic acid, phenyllactic acid and pyrazines. In tests on red grapes, an average reduction of 1.32 log 10 of the spores per gram of fruit was achieved by all CFS in grapes inoculated with Aspergillus ochraceus and by 0.94 log 10 for L. plantarum E3 CFS against Botrytis cinerea. CONCLUSION:The antifungal activity of the fermented CFS by L. plantarum E3 reduced the growth of B. cinerea and A. ochraceus in grapes, which are the main contaminant and main producer of ochratoxin A in these crops, respectively. Therefore, based on the results obtained in this work, use of the strain L. plantarum E3 could be an interesting option for the biopreservation of grapes.

Fungal deterioration by Penicillium species in refrigerated storage conditions is one of the main risk factors for health issues and food waste in the dairy industry. The purpose of this study was to evaluate the antifungal properties of a plastic film carrying whey fermented by lactic acid bacteria (LAB). The results evidenced that a film containing whey fermented using lactic acid bacteria inhibited the growth of Penicillium commune, Penicillium verrucosum and Penicillium solitum for 23, 20 and 17 days, respectively.

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Traditional sourdough is obtained using a mixture of flour and water stored at room temperature until acidification. Therefore, adding lactic acid bacteria (LAB) can improve the quality and safety of sourdough bread. Faced with this problem, four drying techniques—freeze-drying, spray-drying, low-temperature drying, and drying at low humidity—have been applied. Our goals were to isolate LAB strains with antifungal potential against Aspergillus and Penicillium fungi. The antifungal capacity was evaluated with agar diffusion, co-culture in overlay agar, and a microdilution susceptibility assay. In addition, the antifungal compounds generated in sourdough were analyzed. As a result, dried sourdoughs were prepared with Lactiplantibacillus plantarum TN10, Lactiplantibacillus plantarum TF2, Pediococcus pentosaceus TF8, Pediococcus acidilactici TE4, and Pediococcus pentosaceus TI6. The minimum fungicidal concentrations ranged from 25 g/L versus P. verrucosum and 100 g/L against A. flavus. A total of 27 volatile organic compounds were produced. Moreover, the lactic acid content reached 26 g/kg of dry product, and the phenyllactic concentration was significantly higher than the control. The P. pentosaceus TI6 exhibited a higher antifungal capacity in vitro and demonstrated a higher production of antifungal compounds compared to the other strains; therefore, further studies will evaluate the impact of this sourdough in bread manufacture.