applied sciences  
The Antibacterialential Effect of the Films Coated with the Layers Based on _Uncaria tomentosa_ and _Formitopsis betulina_ Extracts and ZnO Nanoparticles and Their Influence on the Secondary Shelf-Life of Sliced Cooked Ham  
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sliced cooked ham [2; 3]. In order to inhibit the growth of microorganisms responsible for food spoilage in ready-to-eat sliced ham, bioactive compounds can be incorporated into product formulation, coated on its surface, or incorporated into the packaging material [1]. Cooked ham packaged in a modified atmosphere is a very popular product, subjected to abundant microbial contamination throughout its shelf life that can lead to deterioration of both textural properties and microbial purity [3; 4]. Consumers are happy to purchase sliced ham packed in a vacuum or in MAP. However, many of them decide to buy cooked ham that is sliced in shops, and there can be situations where it is contaminated by the staff while being cut [3]. The assessment of appropriate secondary shelf life, defined as the time after package opening or after buying a meat product sliced in a butcher shop by a shop assistant during which the food product retains a required level of quality, is pivotal for reducing domestic food waste [4]. The need to produce safe and healthy meat-based products not based on chemical additives has resulted in the control of both spoilage and pathogenic microorganisms. This requirement has been led by consumer demand for safe food products while, in addition, leading to a huge decrease in processing, cutting out many preservatives, and an extension in shelf-life [5]. Active food packaging plays an important role in the preservation of the quality of food products and ensuring their safety [6]. Packaging materials covered with active coatings are designed to release active substances into the product and, by doing so, can extend the shelf life of the food while maintaining its safety and quality [6; 7]. The fabrication of active films, which are based on a surface covering method, contains a number of biobased carriers and antibacterial substances, including those based on plant extracts to create active layers, that can result in an increase in both the primary or secondary shelf-life of foodstuffs [3; 4; 5]. _Uncaria tomentosa_, known as a cat's claw, is a medicinal plant used as complementary medicine to treat many diseases. Extensive research carried out over many years has demonstrated its antibacterial, antiviral, anti-inflammatory, antioxidant, anticonceptive, and immunositulant effects, as well as not being toxic [8; 9]. _Fomitopsis betulina_ is a plant known as a birch polypore. It is a medicinal and edible mushroom (when young). The effectiveness of _F. betulina_ originates mostly from the triterpen, especially lanostane derivatives present in the fungus [9; 10]. The results of the previous work [9] have shown that _Fomitopsis betulina_ extract was unable to inhibit _S. aureus_ growth. A lower than 1-log reduction in the number of bacterial cells was noted for 5% and 10% plant extracts. A greater than 2-log reduction in the number of this strain was only observed in the case of a 50% extract of _F. betulina_. It should be underlined that _U. tomentosa_ extract had a much lower influence on the _S. aureus_ cells than the _F. betulina_ extract. When analyzing the effect of _F. betulina_ and _U. tomentosa_ extracts on _B. subtilis_ cells, it was demonstrated that all of the extracts showed lower than a 2-log reduction but higher than a 1-log reduction in the number of bacterial cells. The results of the previous study have also confirmed that _F. betulina_ and _U. tomentosa_ extracts had no activity against _E.