Assessment of Microbial and Sensory Properties of Bread Fortified with Mushrooms (Pleurotus ostreatus and Calocybe indica)

Abstract

Microbial and sensory properties of bread fortified with mushrooms Pleurotus ostreatus and Calocybe indica were investigated. The bread was prepared with baking formula of 56% wheat flour, 36% water, 3.4% sugar1.6% shortening, 1% skim milk powder, 1% salt, and 1% yeast. Mushroom Powder (MP) was used to substitute wheat flour in bread formulation at 0%, 5%, 10%, 15% and 20%. The 0% inclusion served as positive control, while conventional bread obtained in the market served as the negative control. Microbial and sensory properties of the bread were determined using standard methods. The study revealed that the microbial load of both conventional and mushroom fortified bread was low with bacterial count ranging from 1.7 x 103 cfu/g to 3.3 x 103 cfu/g and fungal counts ranging from 0.3 x 104sfu/g to 7.0 x 104 sfu/g in the mushroom fortified bread. Bacteria isolated were Lactobacillus fermentum, Bacillus cereus, Staphylococcus aureus and Micrococcus luteus, while fungi isolated were Aspergillus niger, Rhizopus stolonifer, Saccharomyces cerevisiae, Penicillum notatum, and Aspergillus flavus. Sensory evaluation indicated no significant difference of overall acceptability between positive control and 5% MP bread (8.7 and 8.2. respectively), however, the acceptability of the positive control was higher and significantly different (P<0.05) when compared to the 10%MP inclusion (7.30). Acceptability further reduced to 4.30 as more MP (20%) was added. The result from this study revealed that microbial load of bread with mushroom was not significantly different (P<0.05) from conventional bread. Moreover, sensory evaluation also revealed that 5%MP inclusion is acceptable while the acceptability of bread fortified with mushroom decreased as MP inclusion increased.