**4.3 Volatile profile by gas chromatography of nano-emulsions**

After the analysis of the previous results was carried out, it may be inferred that the aldehydes present in the Persian lemon oil may be the components that potentiate the antibacterial power. Nano-emulsions of Control Delta (Combination of Surfactants—Span 20: 1.45%, Tween 80: 4.9%, Mesquite Gum 4.9%), both unsterile and sterilized (with 10 and 40 minutes of UV light treatment) were investigated in order to perform a profile analysis of the volatiles by gas chromatography. As observed in **Figure 16**, when the nano-emulsion Control Delta was exposed to different UV sterilization times, the D-limonene signal becomes smaller in comparison with the nano-emulsion sample that was not exposed to UV, so it can be implied that the D-limonene component does not appear to be the main component that acts as an antibacterial agent in this particular sample.

Once the retention time of D-limonene passes (**Figure 17**), the region of the aldehydes begins at higher retention times, and as observed in the previous analysis

**59**

oil droplets.

*Development of Nano-Emulsions of Essential Citrus Oil Stabilized with Mesquite Gum*

of the Persian lemon essential oil, it contains a higher concentration of aldehydes than other citrus essentials oils. There are several aldehyde signals that increase when the sample is subjected to 40 minutes of UV. It was observed that the nanoemulsions contain a higher percentage of aldehydes and a better antibacterial

The oxides zone can be detected after a retention time of 30 minutes (**Figure 18**). In this area, other signals increase when the nano-emulsions are subjected to 40 minutes sterilization process. Thus, it may be inferred that these oxides may also contribute to

This chapter examines the influence of nano-emulsion composition and high pressure homogenization conditions on droplet size and stability. Nano-emulsions with a droplet size smaller than 100 nm (diameter) can be produced by precise conditions of pressure, a specific number of steps in the high pressure homogenizer, and the presence of a combination of surfactants and emulsifiers that is capable to perform ideally under those conditions without degrading. Surfactants and natural gums were used to produce nano-emulsions with small droplets of Persian lemon oil, which has antimicrobial properties, with potential applications in the areas of cosmetics, pharmaceuticals and the food industry. In this particular study mesquite gum was used for the first time to maintain the kinetic stability of the Persian lemon

With the results of the MIC characterization it was confirmed that the nanoemulsions of Persian lemon oil developed under the method described in this research have an antibacterial effect against *Staphylococcus aureus* and *Escherichia* 

*DOI: http://dx.doi.org/10.5772/intechopen.84157*

*Central area of the Control Delta Chromatogram.*

*Oxides area in the Delta Control Chromatogram.*

response after UV treatment.

the antibacterial effect.

**5. Conclusions**

**Figure 17.**

**Figure 18.**

**Figure 16.** *D-limonene signal in the Control Delta Chromatogram.*

*Development of Nano-Emulsions of Essential Citrus Oil Stabilized with Mesquite Gum DOI: http://dx.doi.org/10.5772/intechopen.84157*

**Figure 17.** *Central area of the Control Delta Chromatogram.*

*Nanoemulsions - Properties, Fabrications and Applications*

*Size distribution graph by volume of control delta 10 steps with UV treatment.*

sible for this effect, as compared to the terpene components.

acts as an antibacterial agent in this particular sample.

*D-limonene signal in the Control Delta Chromatogram.*

**4.3 Volatile profile by gas chromatography of nano-emulsions**

that rearrangement of the carbohydrate chains is taking place, thereby reducing the

On the other hand, although the literature indicates that it is not that clear which of the components of the citrus essential oils is the cause of the antibacterial effect, the nano-emulsion with industrial D-limonene results in a higher MIC than Control Delta which is prepared with Persian lemon oil; thus, it may be inferred that the aldehydes of the Persian lemon oil could be the components that are mainly respon-

After the analysis of the previous results was carried out, it may be inferred that the aldehydes present in the Persian lemon oil may be the components that potentiate the antibacterial power. Nano-emulsions of Control Delta (Combination of Surfactants—Span 20: 1.45%, Tween 80: 4.9%, Mesquite Gum 4.9%), both unsterile and sterilized (with 10 and 40 minutes of UV light treatment) were investigated in order to perform a profile analysis of the volatiles by gas chromatography. As observed in **Figure 16**, when the nano-emulsion Control Delta was exposed to different UV sterilization times, the D-limonene signal becomes smaller in comparison with the nano-emulsion sample that was not exposed to UV, so it can be implied that the D-limonene component does not appear to be the main component that

Once the retention time of D-limonene passes (**Figure 17**), the region of the aldehydes begins at higher retention times, and as observed in the previous analysis

**Figure 15.**

hydrodynamic droplet size.

**58**

**Figure 16.**

**Figure 18.** *Oxides area in the Delta Control Chromatogram.*

of the Persian lemon essential oil, it contains a higher concentration of aldehydes than other citrus essentials oils. There are several aldehyde signals that increase when the sample is subjected to 40 minutes of UV. It was observed that the nanoemulsions contain a higher percentage of aldehydes and a better antibacterial response after UV treatment.

The oxides zone can be detected after a retention time of 30 minutes (**Figure 18**). In this area, other signals increase when the nano-emulsions are subjected to 40 minutes sterilization process. Thus, it may be inferred that these oxides may also contribute to the antibacterial effect.
