# The Inactivation of Microscopic Fungi in Bakery Products Using Hurdle Technology--A Case Study
## 3 Results
### Characterization of Microscopic Fungi in the Production Environment and in the Product  
The predominant strains of mold and yeast were isolated from the production environment as well as from the surface of the contaminated product and identified. Macroscopic and microscopic observations of characteristic structures and arrangements (for mold and yeast) and API 20C AUX tests (for yeast) made it possible to identify the tested isolates. Among the molds, two genera, _Aspergillus_ spp. and _Penicillium_ spp., predominated, which grew as colored colonies: black _Aspergillus niger_, green _Penicillium_ spp., or yellowish \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sampling** & **Number of** & **Air** & **Production Area** \\
**Location** & **Sample** & **[cfu/m3]** & **[cfu/25 cm2]** \\ \hline \multirow{4}{*}{Drilling room} & 1 & 1.9 \(\times\) 10\({}^{2}\)\(\pm\) 1.1 \(\times\) 10\({}^{1}\) & 3.2 \(\times\) 10\({}^{4}\)\(\pm\) 6.1 \(\times\) 10\({}^{1}\) \\  & 2 & 2.0 \(\times\) 10\({}^{2}\)\(\pm\) 1.9 \(\times\) 10\({}^{1}\) & 7.4 \(\times\) 10\({}^{3}\)\(\pm\) 2.5 \(\times\) 10\({}^{1}\) \\  & 3 & 1.6 \(\times\) 10\({}^{3}\)\(\pm\) 2.5 \(\times\) 10\({}^{1}\) & 6.8 \(\times\) 10\({}^{4}\)\(\pm\) 5.5 \(\times\) 10\({}^{1}\) \\  & mean & 6.6 \(\times\) 10\({}^{2.4\text{\, A,B}}\) & 3.6 \(\times\) 10\({}^{4}\)\({}^{\text{\, c}}\) \\ \hline \multirow{4}{*}{MAP packaging plant} & 4 & 1.4 \(\times\) 10\({}^{2}\)\(\pm\) 1.3 \(\times\) 10\({}^{1}\) & 3.1 \(\times\) 10\({}^{2}\)\(\pm\) 2.6 \(\times\) 10\({}^{1}\) \\  & 5 & 6.0 \(\times\) 10\({}^{1}\)\(\pm\) 0.0 & 5.6 \(\times\) 10\({}^{3}\)\(\pm\) 4.5 \(\times\) 10\({}^{1}\) \\  & 6 & 2.7 \(\times\) 10\({}^{1}\)\(\pm\) 1.1 \(\times\) 10\({}^{1}\) & 2.4 \(\times\) 10\({}^{3}\)\(\pm\) 2.0 \(\times\) 10\({}^{1}\) \\  & mean & 7.6 \(\times\) 10\({}^{1}\)\({}^{\text{\, b, B}}\) & 2.8 \(\times\) 10\({}^{3}\)\({}^{\text{\, d}}\) \\ \hline \hline \end{tabular}  
* Means within individual categories (air or production area in the drilling room and the MAP packaging plant) followed by different lowercase letters are significantly different. Means in the air category (air in the drilling room, the MAP packaging plant, and atmospheric air) followed by different capital letters are significantly different (Tukey’s test, \(p<0.05\)).  
\end{table} 
Table 4: The number of microscopic fungi on production surfaces and in the air. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Type of Bread**} & \multicolumn{3}{c}{**Microscopic Fungi [cfu/g]**} \\  & **After Half Backing** & \multicolumn{2}{c}{**After Packaging**} \\  & **Crust on Bread** & **Bread Crumb** \\ \hline \multirow{2}{*}{Ciabatta} & & 1.4 \(\times\) 10\({}^{2}\)\(\pm\) 1.1 \(\times\) 10\({}^{1}\) & 5.0 \(\times\) 10\({}^{1}\)\(\pm\) 1.0 \(\times\) 10\({}^{1}\) \\  & & 7.5 \(\times\) 10\({}^{2}\)\(\pm\) 3.3 \(\times\) 10\({}^{1}\) & 7.8 \(\times\) 10\({}^{1}\)\(\pm\) 1.6 \(\times\) 10\({}^{1}\) \\  & & 1.3 \(\times\) 10\({}^{3}\)\(\pm\) 4.3 \(\times\) 10\({}^{1}\) & 9.8 \(\times\) 10\({}^{1}\)\(\pm\) 1.3 \(\times\) 10\({}^{1}\) \\  & Wheat kaiser roll & 1.8 \(\times\) 10\({}^{2}\)\(\pm\) 2.3 \(\times\) 10\({}^{1}\) & 4.8 \(\times\) 10\({}^{1}\)\(\pm\) 8.4 \(\times\) 10\({}^{0}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Number of microscopic fungi in the products. brown _Aspergillus ochracous_. The microscopic images of the molds show conidiophores arrangements characteristic of these genera (Figure 1). Figure 1: Microscopic observation of microscopic fungi isolated from the environment in a bakery (**C**,**F**,**G**) and the surface of baked goods (**A**,**B**,**D**,**E**,**H**) (**A**)—_Candidia spillierromdii_; (**B**)—_Candidia peliculosa_; (**C**)—_Aspergillus niger_; (**D**)—_Aspergillus ochracous_; (**E**)—_Penicillium sp._, (**F**)—_Penicillium sp._, (**G**)—_Saccharomyces cerevisiae_; (**H**)—_Hymphichia burtonii_. Yeast isolates, on the other hand, were mainly the genera _Hymphicia_ sp. ; _Saccharomyces_ sp. ; and _Candida_ spp.