Application of electro-spraying technique and mathematical modelling for nanoencapsulation of curcumin

Electro-spraying Process (ESP) was used to coat extracted curcumin (CUR) with milk protein isolate (MPI) at equal concentration. The variables were applied voltage (AV), pumps flow rate ratio (PFRR) for coating (CUR with MPI), travelling distance (TD for coating and dehydration), ESE and MPI concentrations. They changed respectively from 7.5 to 27.5 kV, 2–10 times, and 5–25 cm, and 1.5–3.5% (w/w). When the MPI concentration, TD, PFRR, and AV of ESE reached respectively to 2.56 %, 16.64 cm, 6.77 times, and 19.06 kV; the resulting nanoparticle diameter and encapsulation efficiency of CUR coated (with MPI) became 232 nm (minimum) and 80.7% (maximum) values. The scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) analysis confirmed that the produced nanoparticles were bead-free, homogeneous, smooth surfaces, and >50% uniformity. While the nanoparticles of CUR had >70% heat resistance (up to 10 min at 120 °C against degradation), it had more than 100% antioxidant capacity in aqueous solution than its free form (because of its appropriate and intact coating). In-vitro studies showed that the nano encapsulated particles released >80% of CUR into the intestinal tract without significant release in simulated gastric fluid.