## 5 Natural Methods
### Essentials Oils
A study showed that _Clamaemelum_ and _Lavandula_ essential oils altered the sensory characteristics of yogurt in an unacceptable way. In contrast, the use of nanoencapsulated essential oils, such as _Thymus capitatus_, had a reduced impact on the sensory properties. Essential oils, such as those obtained from _Thymus zygis_, can replace synthetic preservatives, having significant antibacterial properties and potentiating the effect of other antimicrobial agents. Thus, essential oils can play an essential role in food preservation, providing a natural solution to reduce contamination and increase shelf life [137]. Essential oil nanoemulsions have been studied and applied in various food products. For example, a cumin oil nanoemulsion demonstrated antimicrobial activity against pathogens such as \(S\). _aureus_ and _E. coli_. This method of encapsulating essential oils in nanoemulsions and other nanostructured systems offers a promising solution for controlling microbial contamination in the food industry, including dairy products. However, scaling up these applications to a large scale still represents an economic challenge [8; 154]. In recent years, research has shown that essential oils do not develop microbial resistance, which makes them particularly attractive to synthetic antimicrobials. Although essential oils have been extensively studied for their antimicrobial activity, there is little information on the comparison between the use of whole essential oils and their active components in combating microorganisms. Also, the effect of essential oils on biofilms and spores, more resistant forms of microorganisms, requires further investigation. In addition to their antimicrobial properties, essential oils are also used to improve the flavor of food products, such as chocolate milk or cheeses. Added to these products, they play a crucial role in determining the intensity of the flavor, taste, and smell of the final product. However, the application of essential oils in dairy products is limited because the proteins and fats in these products can interact with them, reducing their antimicrobial effectiveness. For this reason, higher concentrations of essential oils are required to achieve the desired effects, which can negatively affect the sensory properties of the product. A growing area of interest is the use of combinations of essential oils and biocontrol agents, such as bacteriocin-producing LAB, to improve food safety. These combinations have been shown to be effective in extending the shelf life of foods and controlling pathogenic microorganisms without affecting the sensory quality of the products [144]. For example, the combination of chitosan and caraway essential oil has been shown to be effective in improving the sensory properties of foods, while cinnamon essential oil has been successfully used in dairy products to enhance flavor and prevent oxidation. Recent studies have also shown that microcapsules of essential oils added to cheese can extend shelf life and inhibit bacterial growth [149]. Determining the optimal concentrations of essential oils that provide antimicrobial effects without negatively affecting sensory properties is essential for their practical application. Further research is needed to evaluate their effectiveness in combination with other preservation techniques and to explore the impact of essential oils on microorganisms in different states, including spores and biofilms [155]. Although there are many successful examples of the use of essential oils in food, challenges remain in finding the optimal balance between antimicrobial efficacy and maintaining sensory quality. The development of innovative solutions, such as nanoemulsions and the incorporation of essential oils into active packaging, could revolutionize the food industry and provide a natural and safe alternative to synthetic chemical preservatives.