Double Emulsion Character with PFG-NMR- Methods: WOW and OWO Check Access

Double emulsions are of high scientific interest, especially in the field of functional foods. In a first approach, these dispersed systems are described by structural parameters, chemical composition and diffusion parameters. Progress has been made in the characterisation of double emulsions by means of diverse NMR methods with respect to droplet size distribution (DSD), disperse phase ratios (DPR) and molecular exchange (ME) of WOW- and OWO-double emulsions. However, both double emulsion types exhibit different NMR-properties, such that the PFG-NMR methods have to be adapted for the special needs of these systems. Different NMR sequences and data processing steps are compared for OWO and WOW double emulsions. Methods to determine DSD, DPR and ME – relevant for description und understanding of release – are presented and compared with findings from alternative measuring techniques. In this work, diverse NMR methods were summarised to characterise both double emulsion types, WOW and OWO. PFG-NMR is a powerful tool to investigate the structural parameters of double emulsions. The inner DSD and DPR can be determined after the production. NMR relaxometry, using paramagnetic relaxation agents, delivers information about diffusion mechanisms on the molecular scale, which reveals deep insights into molecular diffusion phenomena.