Formulation development and process parameter optimization of lipid nanoemulsions using an alginate-protein stabilizer.

Lipids, especially unstable ones with health beneficiary effects, need to be converted into stable ingredients through nanoencapsulation in a liquid form by development of a nanoemulsion. The primary necessity for synthesis of such nanoemulsions is the development of a formulation for stabilizing the emulsion. Thus parameters to obtain such a stable nanoemulsions were optimized. Hence parameters like temperature, pH and electrolyte concentrations were optimized with respect to different oil:emulsifier ratios (10:1, 15:1, 20:1, 25:1 and 30:1) using sodium alginate, a polysaccharide, as encapsulant and calcium caseinate, a protein, as the emulsifier. Optimization of these process parameters were done based on different physico-chemical techniques like particle-size, zeta-potential, viscosity, lipid content and retention of fatty acid composition by the emulsified oil. Those emulsions which showed maximum resistance to stress and retained minimum particle-size, maximum stability and highest core material retention under stressed conditions were 15:1 and 10:1 emulsion systems. Of the two, 15:1 emulsion system was preferred due to its lower emulsifier requirement. Hence finally the optimized parameters which contributed to the development of the stable emulsions were alkaline pH, temperature of up to 50 ºC and electrolyte concentrations of up to 100 mM.