Purpose: The aim of this study was to quantify fungi throughout a bakery factory located in the state of Sao Paulo, Brazil.
Methods: Raw materials (n = 120) from different lots, while sampling of equipment (n = 31), plastic film (n = 10) and handlers (n = 10) was performed by swab technique. Air samples (total n = 137) were collected in four different sampling days between December, 2014 and January, 2015 using Sartorius MD8 air sampler. Different points of processing were sampled (raw material and ingredients weighing, mixer, oven output, cooling, slicer and package). Quantification of fungi was performed on Dichloran Glycerol agar (DG-18) for all samples, while Dichloran rose bengal chloramphenicol (DRBC) was also used for enumeration of fungi in spoiled bread (n = 25). Fungi identification was performed according to appropriate identification keys. The statistical analyses were performed using ASSISTAT software.
Results: A total of 345 samples were analyzed and 12 different genera were isolated. Penicillium and Aspergillus were the most frequently isolated genera. Average fungi counts were: 3.09 log CFU/g (± 0.5) for whole wheat flour; 3.8 log CFU/g (± 1.8) for grains; 4.9 log CFU/g (± 2.9) for spoiled bread. The counts on environmental surfaces varied from 2.5 to 10 CFU/cm2 (± 3.75), while in the air of processing environment levels were from 1.8 to 2.56 log CFU/m3(± 0.38).
Significance: The knowledge of contamination sources and main species involved in bread spoiled samples comprise very useful data for adoption of measures and development of predictive models aiming to increase shelf life of breads.