# The Inactivation of Microscopic Fungi in Bakery Products Using Hurdle Technology--A Case Study
## 4 Discussion
The vacuum created during packaging is unable to completely remove the gases from the product. However, the lack of increase in oxygen concentration in the package during storage may be due to the fact that during fermentation, carbon dioxide, which is one of the products of fermentation, dominates in the pores of the bread. In order to protect the bakery samples from the growth of microscopic fungi, ethanol was administered to the packages during MAP packaging. The addition of ethanol is one of the methods of preserving bread. [PERSON] and [PERSON] (2011) [PERSON] and [PERSON] (2011) [PERSON] and [PERSON] (2011) indicate that the presence of this compound in the concentration range of 0.2-20% extends the shelf life of baked goods. However, ethanol is very often ineffective against yeast [PERSON] and [PERSON] (2012); [PERSON] (2012). This is confirmed by the results obtained in this study, where microbial infections occurred in some samples with 1.5% ethanol, but in all cases, it was yeast. [PERSON] and [PERSON] (1991) [PERSON] and [PERSON] (1991) [PERSON] and [PERSON] (1991) found that ethanol can significantly extend the shelf life of bakery products without mold contamination when ethanol is added to their surfaces or packaging in an amount of up to 2% by weight of the product. The compound also has a moderate effect in preventing the darkening of baked goods. However, the use of ethanol in food packaging has some limitations. The disadvantage is the strong, undesirable odor of alcohol [PERSON] (2012), which was also found in the presented work. For bread and other bakery products, active ethanol-emitting systems can be used to extend shelf life, and vanilla and other compounds can be used to mask the ethanol odor. The last of the modifications tested for the potential to reduce the development of microscopic fungi in baked goods were starter cultures. The use of lactic acid bacteria in the form of sourdough effectively protected MAP-packed products from microscopic fungal growth. Bread produced with starters also had other advantages: better taste and aroma and delayed darkening process. The antifungal properties of LAB strains of the former genus _Lactobacillus_ (_L. plantarum_, _L. brevis_, or _L. reuteri_) in bakery products have been reported, among others, by [PERSON] et al. (2009) [PERSON] et al. (2009), [PERSON] et al. (2009) [PERSON] et al. (2013), and [PERSON] et al. (2013) [PERSON] et al. (2013). They tested more than a dozen strains of lactic acid bacteria, which showed a strong inhibitory effect on the growth of molds such as _Aspergillus niger_, _Penicillium roqueforti_, and _Endomyces fibuliger_, comparable to the effect of the commonly used preservative calcium propionate. Some lactic acid bacteria also have the ability to react with secondary metabolites of fungi that contaminate food, causing decontamination of mycotoxins [PERSON] et al. (2013); [PERSON] et al. (2014). [PERSON] et al. (2024) [PERSON] et al. (2024) also emphasize that microorganisms contained in sourdough can be used as part of a natural food preservation strategy through the development of antimicrobial metabolites such as short-chain carboxylic acids, ethanol, and bacteriocins. The antifungal activity of _Lactiplantibacillus plantarum_ described by [PERSON] et al. (2022) [42] is caused, among others, by (a) cationic peptides--their antifungal activity results from interactions with negatively charged molecules of the fungal cell membrane, which leads to cell death [43] or (b) unsaturated fatty acids with hydroxyl groups (HUFA)--the antifungal activity is related to their structure [44]. Lactic acid bacteria and their metabolites are a valuable source of antifungal compounds, making them increasingly used in bakery products as natural preservatives