Zinc incorporation capacity of whey protein nanoparticles prepared with desolvation with ethanol

Whey protein isolate (WPI) nanoparticles were prepared using ethanol desolvation, and their capacity to incorporate ZnCl2 was analysed. Desolvation was carried out at pH 9 and the volume of added ethanol was 0–3 times the volume of protein solution. The desolvated solutions were dispersed in acidified water (pH 3) immediately after desolvation. The size of the WPI nanoparticles increased with the volume ratio of ethanol:water used, as well as with the amount of ZnCl2. The nanoparticles showed high incorporation efficiencies, and remained stable after 30 days of storage at 22 °C. The amount of zinc incorporated in the WPI particle suspensions was within the range of daily zinc requirements for healthy adults.

► Whey protein nanoparticles were prepared using an ethanolic desolvation method. ► The nanoparticles were utilised in the encapsulation of zinc ions. ► The extent of encapsulation was investigated using ion chromatography. ► The nanoparticle systems were stable during extended storage (30 days) at acidic pH. ► This methodology can be carried out under food grade conditions.