Evaluation of techno-functional and biochemical characteristics of selected lactic acid bacteria (Lactococcus lactis subsp. lactis and Leuconostoc mesenteroides subsp. mesenteroides) used for the production of Moroccan fermented milk: Lben

The Moroccan traditional fermented milk “Lben” was manufactured using autochthonous and aroma-producing starters by inoculation with four isolated strains including Lactococcus lactis subsp. lactis (coded L. lactis A, E and F) and one Leuconostoc mesenteroides subsp. mesenteroides (coded Leuc. mesenteroides C). The acidifying capacity, volatile compounds, rheological and sensory properties of the products were evaluated. In single culture samples, lactococci showed stronger acidifying capacity and proteolytic activity in comparison with leuconostocs. A significant difference in viscosity was observed between the strains. The L. lactis A and Leuc. mesenteroides C strains caused the most texturising changes in Lben. Rheological analysis indicated that all single culture samples had similar rheological behaviour, and were creamy and viscoelastic, which was relatively more pronounced in experimental Lben produced using the mixed culture. Furthermore, the volatile and sensory characteristics of experimental Lben were very satisfactory since they were much better than those of industrial Lben.