Attività antifungina dell'acido fenillattico prodotto da un ceppo di Lactobacillus plantarum isolato da impasto acido

The ability of sourdough LAB strains to prolong the shelf-life of bakery products is known from a long time. A sourdough Lactobacillus plantarum strain, selected for its antifungal properties, resulted to produce phenyllactic acid (PLA). When sourdough bread was started with the yeast Saccharomyces cerevisiae alone or in combination with the selected L. plantarum strain and contaminated after baking with fungal spores, a delay of fungal growth of 5 days was observed in bread started with the LAB strain with respect to that started with the yeast alone. The antifungal activity of PLA was evaluated against 23 fungal strains including Aspergillus flavus, A. ochraceus, A. niger and Penicillium roqueforti. The minimal inhibitory (MIC90) and fungicidal (MFC) PLA concentrations were determined together with the ability to "delay" mould growth. These results offer promising perspectives for the application of L. plantarum strain or PLA in order to extend the shelf-life of bread and bakery products.