Can broad bean (Vicia faba) and white lupin (Lupinus albus) flours serve as carbon sources to support probiotic growth?

There is growing interest in identifying substrates that support the growth of probiotics in foods. Pulses are an excellent source of nutrients and bioactive compounds, including non-digestible oligosaccharides from the α-galactoside group, which are probiotic growth factors. This study aimed to evaluate the potential of white lupin and broad bean flours to support the growth of seven probiotic strains of Lactobacilli and Bifidobacterium . Different Man-Rogosa-Sharpe broth media were prepared using whole or dehulled flour as carbon sources at different concentrations (20, 30, 40, and 60 g/L) and inoculated with 2% (w/v) of each probiotic strain. Viable cell numbers and medium acidification were monitored throughout fermentation and compared to negative (MRS without a carbon source) and positive (MRS with 20 g/L glucose) controls. White lupin at 60 g/L concentration proved to be a suitable carbon source for both Lactobacillus acidophilus Ki and Lactobacillus casei ssp. paraca sei L26, while concentrations of 40 g/L and 60 g/L supported Bifidobacterium animalis Bb12 growth. Flour concentration had a greater impact on probiotic growth than composition (hull vs. dehulled). These results suggested that white lupin is a promising ingredient for the development of functional foods.