Effect of Bacterial and Fungal Isolates on the whole Grain Millet Sourdough Breads

Abstract

The sourdough fermentation technique has the potential to improve the nutritional profile and safety of cereal fermented foods which forms the bulk of the diet of rural dwellers in sub-Saharan Africa. This study enumerates the bacterial and fungal isolates responsible for the fermentation of millet sourdoughs, evaluates the antimicrobial safety of the sourdough starters and the quality of bread produced thereafter. The individual flours were spontaneously fermented in the ratio 1:1 (w/v) for 48 h. At the end of the fermentation, the microbial consortium of the sourdough meals obtained were determined and also screened for antagonistic activity against selected pathogens. Chemical analysis analyses were carried out on the breads following well established procedures. Semi trained panellists were employed to access the organoleptic attributes of the product. All the sourdough starters revealed strong clearance zones against the selected food borne pathogens. The proximate compositions of the breads were improved by the sourdough fermentation process compared with the raw flour. The moisture content of flour determined ranged from 7.48 to 11.20% while the protein, fat, ash, crude fibre and carbohydrate were 9.53 to 12.4%; 2.13 to 2.78%; 0.82 to 2.87%; 2.10 to 4.67% and 71.83 to 76.33% respectively. The carbohydrate content of the breads reduced with fermentation and ranged from 63.10% to 73.33%% while the protein, ash, crude fibre and fat content ranged from 11.57 to 15.31%; 2.39 to 3.08%; 1.76 to 3.62% and 7.15 to 12.32% respectively. The highest value for calcium 48.86 mg/100 g was exhibited by pearl millet bread. Sensory evaluation showed significant difference in the bread samples. The findings have suggested that indigenous wholegrain cereals could be employed for bread production, thus reduce importation and over dependence of wheat flour and white pan bread consumption