Effect of Storage Conditions on the Microbial and Proximate Composition of Bread Made From Wheat Flour and White Flour

Abstract

Bread is one of the most consumed staple foods in the world. It is a good source of nutrients, such as carbohydrates, protein, and fat and micronutrients (minerals and vitamins) which are essential for human health. The aim of the research is to determine the effect of storage conditions on the microbial and physico-chemical composition of bread from wheat flour and white flour. The fresh samples (white and wheat bought from the super market) were cultured according to the standard microbiological procedures. The Total Heterotrophic Bacterial Count (THBC) of the fresh white flour bread sample (FB) obtained was 1.3×104CFU/g (4.11logCFU/g) while that of Wheat bread (WB) sample was 1.2×104CFU/g (4.00 logCFU/g). The total Staphylococcal Count (TSC) of the samples was recorded as 4.9×103 CFU/g (3.69logCFU/g) which was higher in comparison to that of wheat bread with the count of 1.4×103CFU/g (3.14logCFU/g). Decrease in THBC of wheat bread and white bread sample stored at refrigeration temperature as compared to the bread samples stored at ambient temperature in relation to the days of storage was observed. Refrigeration had little effect on the growth of fungi as observed in this study as the Total Heterotrophic Fungal count (THFC) of refrigerated white bread sample increased from 2.0×103CFU/g (3.30logCFU/g) on the day 6 to 8.9×103CFU/g (3.94logCFU/g) on the day 8. The microorganisms isolated were Micrococcus sp, Staphylococcus sp, Bacillus p, Aspergillus niger, A. flavus, Rhizopus sp, Mucor sp, Penicillium sp, Candida sp, and Saccharomyces of which Bacillus and Aspergillus where most occurring among bacteria and fungi respectively. The moisture content, crude lipid, crude protein of the white bread sample were higher than those of wheat bread while the ash content, crude fiber and carbohydrate were higher in the wheat bread sample as compared to those of White bread sample. From the result obtained in the study, it was observed that refrigeration temperature was effective in the increase in shelf life of bread by the reduction in bacteria growth in bread thus, it can be recommended for the storage of bread.