Lactic fermentation of cereals aqueous mixture of oat and rice flours with and without glucose addition

Abstract

Studies of the ability of probiotics to ferment cereal flours are necessary to obtain products with enhanced nutritional value. In this study, Lactobacillus paracasei CBA-L74 was used to ferment cereal aqueous mixtures containing both oat (7.5% w/v) and rice flours (7.5% w/v), with and without glucose, to understand whether glucose addition could have any effect on growth and metabolism. Viability, pH, metabolites production during fermentation (24 h, 37 °C) and substrates reduction were analysed. The strain showed good growth in the cereal aqueous mixture both with and without glucose addition, but suspensions prepared with glucose showed the best results. A bacterial concentration of 7 log CFU mL^-1, a pH value of 4.70 and lactic acid production of 1250 mg L^-1 were achieved when fermentation was performed without glucose addition, while in the presence of glucose, a t₂₄ bacterial growth of 8 log CFU mL^-1 was reached, with a pH value of 3.11 and lactic acid production of 6050 mg L^-1.

Keywords: Fermented food; Food science; Food technology; Glucose; Lactobacillus paracasei CBA L74; Nutrition; Oat flour; Probiotics; Rice flour.