Effect of the Amount of Polysorbate 80 and Oregano Essential Oil on the Emulsion Stability and Characterization Properties of Sodium Alginate Microcapsules.

Cetin Tas,Juste Baranauskaite,Liudas Ivanauskas,Burcu Uner,Mehmet Ali Ockun

doi:10.3390/molecules26206304

Abstract

Essential oils have a high volatility that leads to evaporation and loss of their pharmacological effect when exposed to the environment. The objectives of the present work were to prepare microcapsules with oregano essential oil by extrusion using sodium alginate as a shell material and non-ionic surfactant polysorbate 80 as an emulsifier to stabilize the emulsion. The present study was aimed to evaluate the physical parameters of microcapsules and to compare the influence of the amount of emulsifier and the essential oil-to-emulsifier ratio on the capsules’ physical parameters and encapsulation efficiency; to our knowledge, the existing research had not yet revealed whether unstable emulsion affects the encapsulation efficiency of oregano essential oil. This study showed that increasing the emulsifier amount in the formulation significantly influenced encapsulation efficiency and particle size. Moreover, increasing the emulsion stability positively influenced the encapsulation efficiency. The emulsion creaming index depended on the emulsifier amount in the formulation: the highest creaming index (%) was obtained with the highest amount of polysorbate 80. However, the essential oil-to-polysorbate 80 ratio and essential oil amount did not affect the hardness of the microcapsules (p > 0.05). In conclusion, the obtained results could be promising information for production of microcapsules. Despite the fact that microencapsulation of essential oils is a promising and extremely attractive application area for the pharmaceutical industry, further basic research needs to be carried out.

Highlights

Origanum L., which belongs to the Lamiaceae family, is an annual, perennial, or shrubby plant [1]
The volatility of essential oils limits their application as food supplements, as they are unstable and have solubility problems and require encapsulation
It is important to protect the active ingredients of essential oils in order to not lose their biological efficiency

Summary

Introduction

Origanum L., which belongs to the Lamiaceae family, is an annual, perennial, or shrubby plant [1]. The main components in the structure of oregano oil are thymol and carvacrol. Depending on the species and growing conditions, one or both of these compounds can be present in high amounts in oregano species [3,4,5,6]. For this reason, the chemical content of the oil is important for its effectiveness [7]. Oregano essential oil has powerful health benefits. The antispasmodic, analgesic, diaphoretic, carminative, antioxidant, antibacterial, and antifungal activities of oregano essential oils have been extensively studied. It is important to protect the active ingredients of essential oils in order to not lose their biological efficiency

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Conclusion