Stability of oregano essential oil encapsulated in double (w/o/w) emulsions prepared with mechanical or high-pressure homogenization and its effect in Aspergillus niger inhibition

摘要

High-pressure homogenization and mechanical homogenization were used for theproduction of water-in-oil primary emulsions (PE) containing oregano essential oil.Different PE concentrations and homogenization parameters were tested during theproduction of water-in-oil-in-water (W/O/W) double emulsions to assess their effecton emulsion stability during 25 days of storage by determining emulsion dropletsize and creaming; the antifungal activity of W/O/W emulsions against Aspergillusniger was evaluated. The smallest droplet sizes of W/O/W emulsions were obtainedwith a mechanical homogenization velocity of 5,800 rpm, formulated with a PE concentrationof 20%. The creaming behavior of emulsions during storage followed asecond-order kinetic starting on day 1, presenting maximum values from 15% to 35%and creaming rates from 3.16%/day to 7.3%/day. The antifungal activity of W/O/Wemulsions against A. niger was demonstrated. Binary logistic regression was used topredict A. niger inhibition, resulting in being dependent on the creaming behavior ofthe emulsions.