Selection of Algerian lactic acid bacteria for use as antifungal bioprotective cultures and application in dairy and bakery products

In the context of a demand for “preservative-free” food products, biopreservation appears as a promising alternativeto either replace or reduce the use of chemical preservatives. The purpose of this study was to evaluatethe antifungal activity of a collection of lactic acid bacteria (n=194), and then to evaluate the applicability andefficacy of selected ones used as bioprotective cultures against mold spoilers in dairy and bakery products. First,lactic acid bacteria were isolated from various Algerian raw milk samples and Amoredj, a traditional fermentedproduct. Secondly, in vitro screening tests against Mucor racemosus UBOCC-A-109155, Penicillium communeUBOCC-A-116003, Yarrowia lipolytica UBOCC-A-216006, Aspergillus tubingensis AN, Aspergillus flavus T5 andPaecilomyces formosus AT allowed for the selection of 3 active strains, namely Lactobacillus plantarum CH1,Lactobacillus paracasei B20 and Leuconostoc mesenteroides L1. In situ tests were then performed to validate theiractivity in actual products (sour cream and sourdough bread) challenged with fungal spoilers. These testsshowed that antifungal LAB could slow the fungal target growth and could be candidates of interest for industrialapplications. Finally, organic acids and various antifungal compounds produced in sour cream and sourdoughbread by the selected LAB, and thus potentially supporting the observed antifungal activity, were identified andquantified by HPLC and LC-QTOF