## 3 Edible Coatings
### Active Edible Packaging
#### 3.4.4 Nanoparticles and Nanomaterials as Active Compounds
The greatest development of nanotechnology occurs in China, Japan, the European Union, and the United States, where the National Nanotechnology Initiative allocates USD 3.7 billion for a 4-year investment plan for research in the field of nanotechnology [151]. Due to the difficult specificity and complex structure of nanomaterials, the REFINE project of the Horizon 2020 program was created, which included information on regulatory challenges and the development of appropriate tools. The surveys and interviews showed that the current regulatory guidelines are difficult to access and not always understandable [156]. Recently, nanotechnology has offered the food industry many new approaches to improve food quality, durability, and safety. Unfortunately, there are concerns from consumers, regulatory agencies, and the food industry regarding the potential for side effects from using modified nanoparticles in food, e.g., through leakage from packaging material. There are reports that many of the nanoparticles used do not hurt human health, but there are also reports of their harmful effects, causing damage to cells or organs, as well as damage to microbial cells that inhabit the human digestive tract [157]. However, according to [PERSON] et al. [158], the large specific surface of the nanoemulsion causes rapid digestion by enzymes from the gastrointestinal tract, limiting the occurrence of a possible toxic effect that may occur due to the accumulation in organ cells. Several papers report that zinc oxide (ZnO) is not toxic to human cells and thus could be used as an antibacterial agent in food packaging. Nanomaterials are characterised by a high ratio of the specific surface area of nanoparticles to their volume, attributed to their different antibacterial mechanisms [159]. In addition to the huge benefits, nanotechnology also carries some risks that must be considered in everyday use. According to [PERSON] et al. [114], this ratio may have an adverse effect and cause a potential threat to human health due to the emerging dissimilarity of nanoparticle forms from the original forms. Differences in the toxicity of nanoparticles may vary depending on their type, concentration, exposure time, and sensitivity to given conditions. A migration test should be performed to determine the risk of ingredients from any new food packaging material, which means \"determining the release of substances from a material or article either into food or into food simulant\". In addition, it is a promising film-forming material approved by the US Food and Drug Administration (FDA). Coatings used on the surface of fruit and vegetables containing silver nanoparticles have an antimicrobial effect, the permissible level of which is 0.06 mg/L, conditioned by EU regulations. Unfortunately, consumers react reluctantly to emerging innovations, treating them as a threat to their health and the environment. The main reason for this is assumed to be legislative barriers and emerging uncertainty regarding the effectiveness of applying such systems, taking into account economic and environmental aspects. At present, the legislation is still in its early stages, and only five Member States of the European Commission (EU) have adopted legislation on nanomaterials or goods containing nanomaterials, i.e., Belgium, Denmark, France, Switzerland, and Sweden [160]. Although nanotechnology has been developed primarily for food packaging, it has not yet found widespread use. This was mainly due to too few reports on the uncertainty of the impact on human health and the environment. In addition, detecting nanomaterials in food products when they are released or react with food content is very complicated [46].