Effect of Ultrasonication and wall materials on the stability, rheology, and encapsulation efficiency of vitamins in a lipid-based double emulsion template

The study includes structuring lipid-based systems by double emulsion methodology using ultrasonication for 1-5 min without involving sterols, followed by freeze-drying. It contained multi-vitamins (A, D, B-9, B-12) in a two-stage emulsion process in the ratio (20:80- emulsion1: emulsion2). A total of 15 formulations (R1 to R15) were prepared and were further studied for properties viz. size, PDI, zeta potential, encapsulation efficiency, and rheological parameters. The size of particles varied from 143 to 396 nm, polydispersity index from 0.314 to 0.866, and zeta potential from -20 to -33.5 mV. Vitamin A, D, and B-12 had excellent entrapment efficiency (>96%) but, vitamin B-9 showed comparatively poor entrapment. The encapsulation efficiency of vitamins slightly depended on the compositions but were nearly independent of ultrasonication time. The trehalose and lecithin displayed a significant impact on the size and zeta potential respectively. A weak negative correlation of ultrasonication time with size was observed. In comparison to trehalose, lecithin and MPI concentration have more impact on the viscosity. The formulations exhibited pseudoplastic flow behavior and good mechanical strength (angular frequency 2.45-13 Hz). Herschel-Bulkley and Power model showed the best fit for R1 to R10, and R11 to R15 respectively. Low-fat biscuits fortified with developed liposomes provided maximum retention of vitamins than the un-encapsulated vitamins. Practical Applications Vitamins are susceptible to degradation when exposed to adverse environmental conditions, hence it is often enclosed within a membrane to prevent deterioration and ensure maximum uptake. Simultaneous co-encapsulation of hydrophilic and hydrophobic vitamins can be a promising strategy to enhance the delivery of labile micronutrients. The developed lipid-based emulsions/powder have a wide applicability, can be used for the development of functional foods such as confectionery and bakery items. The presence of an extra protective membrane facilitates reduction in degradation of nutrients, thereby favoring better uptake during ingestion.