Development and characterization of ethanol-free spearmint essential oil nanoemulsion for food applications using the low energy technique

A.E Edris

doi:10.3989/gya.0666201

Abstract

Different emulsifiable concentrates containing spearmint essential oil (SEO) were made and evaluated for their potential for giving ethanol-free nanoemulsion spontaneously upon dilution into water. Each one of these formulas had its specific composition regarding the type of excipients, surfactants, surfactant/SEO ratio and surfactant concentration. The results of this evaluation indicated that the chemical composition of SEO has a profound effect on the formation and physical stability of the nanoemulsion. The incorporation of excipients such as long chain triglyceride and propylene glycol into the emulsifiable concentrates at only 1.0% can lead to a stable nanoemulsion that resists Ostwald ripening. A particle size measurement showed that the diameter of SEO in the nanoemulsion was 28.2 nm and its nanostructure was maintained for 3 months. The application of a mixture of binary nonionic food-permitted surfactants enhanced the thermal stability of the nanoemulsion at up to 50 ᵒC. The developed ethanol-free SEO nanoemulsion has promising industrial applications in food and beverage flavoring.

Highlights

Essential oils (EOs) are natural volatile extracts obtained from aromatic plants
No traces of triglyceride oil were used in this formula to see if the desired nanoemulsion could be developed using spearmint essential oil (SEO) as the sole oil phase
Our results indicated that the affinity between (SEO/long chain triglyceride (LCT)) and Tween 80, which is used as a surfactant, is higher than that of (SEO/medium-chain triglyceride (MCT)) and the same surfactant

Summary

Introduction

Essential oils (EOs) are natural volatile extracts obtained from aromatic plants. They are frequently used as flavoring agents in food and beverages. Water, which is the most appreciated and economically feasible solvent, is inappropriate for the dilution or delivery of EOs due to their hydrophobic nature. The emulsification of EOs in water to form solvent-free flavor delivery systems has become a promising trend for the food and beverage industry (Given, 2009). In such emulsions, EOs exist as tiny microscopic particles dispersed homogenously in water using the appropriate surfactant. Afterwards the oil droplets will flocculate, coalesce and separate from the system

Methods

Results

Discussion

Conclusion