The garlic (A. sativum L.) extracts food grade W1/O/W2 emulsions prepared by homogenization and stirred cell membrane emulsification

Abstract

Controlled droplet size and high encapsulation yield of bioactive components in an emulsion carrier are crucial for its successful implementation in functional food preparations. In order to provide the protection and controlled release, water and/or ethanol garlic extracts were encapsulated into the internal water phase of double water-in-oil-in-water emulsions. The oil phase was a mixture of pumpkin seed and sunflower oils, stabilizers were PGPR and Tween 20 and osmotic regulators were NaCl and glucose. For the secondary emulsification step homogenization and stirred cell membrane emulsification (ME) were employed. A sintered-glass filter-disc membrane was assessed as a possible membrane material for ME. The optimal transmembrane pressure and shear stress on the membrane surface were determined. The use of ME led to an improvement of the double emulsions droplet uniformity and better barrier properties in terms of higher encapsulation yield of internal water droplets and slower storage release estimated by measurement of a marker substance concentration in the continuous phase.