# The Effect of Ethanol Propolis Extracts on Inhibition of Growth of _Fusarium solani_ on Hen Eggs
## 1 Introduction  
Hen eggs are widely available food products and valuable in terms of their nutritional and health properties [1]. As a rule, most of the eggshell immediately after laying are microbiologically uncontaminated or contain few microorganisms [2, 3]. In the place of laying eggs, they are subject to secondary pollution, which is most affected by lack of hygiene [4, 5, 6, 7]. Bacteria and fungi contaminate hen eggs. The total number of viable microorganisms is important because it determines the safety of eggs and their shelf life. Bacteria of the genera _Staphylococcus_[8], _Bacillus, Stentrorophomonas_ and _Pseudomonas_[9], _Enterococcus_ and the species _Escherichia coli_[10, 11] are very often isolated from eggshells. Fungi are also present on the surface of the shells, which are mainly responsible for the spoilage of eggs. Fungal spores can penetrate through the pores of the eggshell into the interior of the egg, and after the development of mycelium; they can cause an unpleasant odor and taste of the egg [1]. [PERSON] et al. [4] isolated _Aspergillus, Penicillin, Fusarium, Mucor, Rhizopus_ and _Alternaria_. [PERSON] et al. [1] identified _CIndosporium macrocarpum_ and _Botrytis cinerea_ inside the eggs. [PERSON] et al. [12] reported the presence of toxigenic strains (_Fusarium culmorum_ and _F. equiseti_) in eggs. The natural protection of hen eggs against microorganisms is the shell covered with the cuticle and subvalvular membranes [13]. Nevertheless, eggs spoil and their quality deteriorates [14]. In order to avoid and reduce economic losses and reduce the risk to public health, modern techniques are being developed to protect table eggs against the development of microorganisms, e.g., eggshell coating, as well as disinfection using various substances and physical agents [7, 15]. Good microbiological protection is provided by coating eggs with bioactive coatings containing plant essential oils and other natural substances [16, 17]. Propolis is a complex plant substance whose components are derived from secretions of a resinous nature from the buds, flowers and leaves of trees, e.g., poplar, willow, elm, alder and conifers [18; 19; 20; 21]. Propolis exhibits antimicrobial activity due to its rich chemical composition of bioactive ingredients, i.e., flavonoids, phenols, terpenoids, aliphatic acids and their esters, carboxylic acids and their esters, alcohols, polyphenols, aldehydes, and ketones [22]. Propolis owes its anti-mold properties to flavonoids [23; 24]. Ethanol extract of propolis in concentrations of 1-10% is effective against food-contaminating fungi: _Aspergillus versicolor_, _Penicillium aurantiogriseum_[23], _Alternaria alternata_, _Fusarium_ sp., _Ullo-cladium_ sp., _Botrytis cinerea_, _P. expansum_, _Colletotrichum musae_[25; 26], and _A. niger_, _A. flavus_, _P. chrysogenum_, _Rhizopus stolonifer_[27]. Due to its high antioxidant activity and antimicrobial properties, propolis is considered as a natural preservative [22]. Propolis extracts are added directly to food, or the surfaces of products are coated with polymer coatings containing propolis extract in their composition [22; 28]. Ethanol or water extracts of propolis inhibit fungal growth in apple juice [29] and delay microbial spoilage of strawberries [30; 31]. So far, propolis has been used to a small extent to reduce the microflora on the shells of hen eggs [16; 32]. Nevertheless, the coating of hen eggshells with propolis reduces the total number of bacteria and aerobic mesophilic bacteria [7; 33; 34], and inhibits the growth of _Salmonella_ and coliforms [35; 36]. The overall quality of table eggs was improved by a coating with rice protein coatings containing propolis extract [37] and a propolis coating [38]. In our previous studies, we documented the antibacterial and antifungal activity of ethanolic propolis extract [39; 40] and characterized the physical and anti-mold properties of a pullulan coating containing ethanolic propolisik extract [41].