Application of pure and mixed probiotic lactic acid bacteria and yeast cultures for oat fermentation

Fermentation of a prebiotic containing oat substrate with probiotic lactic acid bacteria and yeast strains is an intriguing approach for the development of new synbiotic functional products. This approach was applied in the present work by using pure and mixed microbial cultures to ferment a heat-treated oat mash. Results show that the strains studied were appropriate for oat fermentation and the process could be completed for 6-10 h depending on the strain. The viable cell counts achieved within this time were above the required levels of 10(6)-10(7) cfu ml(-1) for probiotic products. Both single lactic acid bacteria strains and mixed cultures of the same strains with yeast were found suitable for oat fermentation. However, the pure LAB cultures attributed better flavour and shelf life of the oat drinks. The content of the prebiotic oat component beta-glucan remained within 0.30-0.36% during fermentation and storage of the drinks obtained with each of the strains used. Thus, these products would contribute diet with the valuable functional properties of beta-glucan. Also, the viability of pure and mixed cultures in the oat products was good: levels of cell counts remained above the required numbers for probiotic products throughout the estimated shelf-life period. (c) 2005 Society of Chemical Industry.