Stability of Aqueous Emulsions of the Essential Oil of Hops

Abstract

Hop oil emulsions prepared from different varieties of hops have been found to exhibit enhanced physical stability on the addition of blends of the emulsifiers Span 20/Tween 80 or Span 60/Tween 60. Examination of the particle size and volume distributions of an emulsion by use of a Coulter Counter was found to be an excellent method of monitoring its stability. An indication as to the relative efficiency of emulsifiers can be obtained from Coulter Counter measurements on hop oil emulsions after storage for 4 days. The use of an ultracentrifuge provies a rapid means of testing emulsion stability and hence the effectiveness of emulsion stabilizers.

In vitro assessment of antimicrobial activity of carvacrol, thymol and cinnamaldehyde towards Salmonella serotype Typhimurium DT104: effects of pig diets and emulsification in hydrocolloids

“…Their application in aqueous systems usually requires formulation to form a homogenous aqueous system in order to deliver their functions. Surfactants such as Tween 20, Tween 80, ethanol and dimethyl sulfoxide have been used to emulsify EOs and their component solutions (Chilton and Laws 1980;Mann and Markham 1998). The use of polysaccharides, such as agar, carrageenan and gelatin, as stabilizers has also been reported (Skandamis et al 2000;Gill et al 2002;Burt and Reinders 2003;Burt et al 2005).…”

Food Emulsifiers and Their Applications

“…This type of emulsions is difficult to prevent creaming because of the density difference between the dispersed and continuous phase. Viscosity of continuous phase and droplet size distribution also have influence on creaming (Chilton and Laws, 1980).…”