Antifungal Activity in Faba Bean and Pearl Millet Fermentation

The literature review illustrated the negative impacts of mold spoilage in baked goods and the significance of lactic acid fermentation used to prevent mold growth, with a special emphasis on the mechanism of antifungal metabolites produced by lactic acid bacteria. A brief introduction of the raw materials (faba bean and pearl millet) was also involved. The aim of this study is to explore the potential of different strains of lactic acid bacteria producing antifungal compounds during faba bean and pearl millet fermentation, to facilitate their application in baked foods with extended shelf-life. Different species of lactic acid bacteria isolated from faba bean and pearl millet in previous studies were used singly as a starter for sourdough fermentation. Antifungal assays were carried out on target molds and selected sourdoughs showing antifungal activity were analyzed to assess the nature of antifungal compounds (e.g. organic acids and proteinaceous compounds). All of the water-soluble extracts from sourdoughs were able to inhibit the growth of the indicator molds P. paneum and P. albocoremium, but not A. niger. This was in agreement with previous findings, showing that sensibility towards different antifungal compounds is not identical across different molds. The concentration of organic acids and the potential proteinaceous nature of the most active extracts was also established. It was hypothesized that the organic acids produced during fermentation can act in synergy with proteinaceous compounds and could contribute to the antifungal activity of faba bean sourdough fermented with L. sakei F1410 and L. mesenteroides I21 and of pearl millet sourdoughs fermented with P. pentosaceus A133 and A1231. Furthermore, small molecular peptides generated possibly through proteolysis of proteins in faba bean sourdough fermented with P. pentosaceus I02 and in pearl millet sourdough fermented with L. palantarum A103 could be responsible for the antifungal effect