Improvement of the texture and dough stability of milk bread using bioemulsifiers/biosurfactants produced by lactobacilli isolated from an indigenous fermented milk (pendidam)

This study aimed at valorizing the emulsifying properties of bioemulsifiers/biosurfactants (BE/BS) derived from lactobacilli in baking. Lactobacilli strains isolated from six samples of pendidam were screened for BE/BS production using the oil spreading test. The BE/BS produced by the six positive strains grown on MRS broth free of tween 80 were extracted by ethanol precipitation with yields ranging from 5.80 ± 1.23 to 61.80 ± 4.74 g/L. Four BE/BS displayed the highest emulsification index (60.03 ± 3.33 to 67.60 ± 3.38%). The emulsifying and surface activities of these BE/BS were stable after heat treatment (121 °C/15 min). BE/BS at 0.5 g/100 g was used as substitute of soya lecithin in the formulation of milk bread and its rheological properties on dough and bread texture were assessed. BE/BS significantly decreased dough viscosity compared to the commercial emulsifier. The hardness of the crumb of milk bread containing BE/BS was reduced and its homogeneity improved. The in-situ properties of BE/BS produced by the isolate PM2B in milk bread preparation were more pronounced than that of the commercial emulsifier. This study demonstrated the potential use of BE/BS derived from lactobacilli in bakery products as substitute of chemical emulsifiers and suggests pendidam as a good source of lactobacilli with highest BE/BS production yields.