Microbial ecology of muffins baked from cassava and other nonwheat flours

Cassava flour was evaluated as a partial substitute for wheat flour in gluten-free muffins. Four replicate test bakes were carried out to evaluate the microbial ecology of two muffin mixes, made with different combinations of cassava, soya, sorghum, sago, and potato flour. The muffins were baked at 180 degrees C for 25 min, stored at 30 degrees C and analysed microbiologically for up to 10 days post-baking. Raw materials were similarly analysed microbiologically on the day of baking. Characterization of predominant bacterial and mould isolates from the raw materials and the muffins was carried out. The rope-free and minimum mould-free shelf life of both muffin types were approximately 1 day and approximately 3 days, respectively. The predominant bacterial isolates from the raw materials and muffins were Bacillus species (83 and 99%, respectively). The moulds predominating in the raw materials were Gloeosporium (42%), Penicillium (13%) and Mucorales (13%), and from muffins Penicillium (37%) and Aspergillus (37%).