Polyols, High Pressure, and Refractive Indices Equalization for Improved Stability of W/O Emulsions for Food Applications

• Published in: Journal of dispersion science and technology Vol. 22; no. 2-3; pp. 269 - 280
• Main Authors: Benichou, Axel, Aserin, Abraham, Garti, Nissim
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 31.03.2001; Taylor & Francis
• Subjects: Biological and medical sciences; Chemistry; Colloidal state and disperse state; Droplet disruption; Emulsions. Microemulsions. Foams; Exact sciences and technology; Food additives; Food industries; Fundamental and applied biological sciences. Psychology; General and physical chemistry; General aspects; High pressure; Polyols; Stability; Submicronal emulsions; Transparent emulsions; W/O Emulsions; 1,8-p-Menthadiene; Particle size; Water oil emulsion; Stability; Refraction index; Lipids; Experimental study; Triglyceride; Synergism; Ethylene oxide polymer; Terpene; Pressure effect; Triacylglycerol; Optical properties; Preparation; Surface properties; Polyol; Aqueous solution
• ISSN: 0193-2691; 1532-2351
• DOI: 10.1081/DIS-100105214

Mixtures of polyols (glycerol, propylene glycol, glucose) and water were emulsified in oil (isopropyl myristate (IPM), medium chain triglycerides (MCT), long chain triglycerides (LCT), and d-limonene) under elevated pressures and homogenization, in the presence of polyglycerol polyricinoleate (PGPR), glycerol monooleate (GMO), and their mixture as emulsifiers to form water-in-oil emulsions. High pressures was applied to: a) the emulsion, b) the aqueous phase and c) the oil phase in the presence of the emulsifiers (PGPR and GMO). Under optimal pressure (2000 atms) applied to the ready-made emulsion or to the aqueous phase prior to its emulsification, and with optimal composition (30wt% polyol in the aqueous phase and MCT as the oil phase), the aqueous droplets were stable for months and submicron in size (0.1 μm). Moreover, due to equalization of the oil and the aqueous phases refractive indices, the emulsions were almost transparent. Pressure and polyols have synergistic effects on the emulsions stability. During preparation, surface tensions and interfacial tensions were dramatically reduced until an optimal water/polyols ratio was achieved, which allows rupturing of the droplets to submicronal size (0.1 μm) without recoalescence and fast diffusion to the interface. These unique W/O emulsions are suitable for preparing W/O/W double emulsions for sustained release of active materials for food applications.