Evaluation of the effect of homogenization energy input on the enclosed water volume of concentrated W/O/W emulsions by low-resolution T2-relaxometry

The usefulness of low-resolution NMR for W/O/W double emulsion characterization was evaluated. Whereas pfg-NMR diffusion experiments enabled the detection of phase inversion and water droplet diameter distribution in the primary W/O emulsion, T2 relaxation measurements allowed discriminating internal and external water when a paramagnetic agent, such as manganese dichloride was added to the W/O/W emulsion. The study aimed to entrap a maximal amount of water in the W/O emulsion in order to obtain a concentrated W/O/W emulsion. In addition, the impact of homogenization duration and intensity on the enclosed water volume of the double emulsion was investigated. The results indicated that high-intensity process conditions drastically decreased the yield of the W/O/W emulsion. [Display omitted] ► Phase inversion of the primary W/O emulsion was detected by LR pfg-NMR diffusometry. ► A non-destructive method for the yield determination of W/O/W emulsions is proposed. ► The method consists of LR NMR T2-relaxometry and requires the addition of MnCl2. ► Impact of homogenization energy on the yield of the W/O/W emulsion is investigated. ► Food grade double emulsions with 18% (v/w) internal water could be obtained.