Evaluation of the stability, color, and viscosity for whey protein-pectin nano complexes as nano carriers of orange peel oil

Orange peel oil,a widely used industrial flavoring, is volatile and chemically unstable in the presence of air, light, moisture and high temperatures. Biopolymer Nano complexes, a bunch of Nano carriers, are produced between groups of charged polysaccharides and proteins with the use of electrostatic interactions. The nanoparticles are able to carry, protect, and increase their bioavailability of food-drug materials. Hence, in this study, the Nano complexes of pectin- whey protein concentrate, as a carrier of orange peel oil, were produced and the features of prepared Nano complex solution with various concentrations of whey protein (4, 6 and 8%), pectin (0.5, 0.75 and 1%) and different values of pH (3, 6 and 9) were studied. The Viscosity, stability and color (index L *) of the treated designs, done in a response surface methodology, were examined. The results showed that whey protein 4% and pectin 1%( with a pH of 3 and 9) had the lowest and highest stability respectively. Also this treatment with a pH of 3 showed the highest viscosity as well as the highest L *. The lowest viscosity was achieved by whey protein 6% and pectin 0.75% with a pH of 3, and because of the unbalanced compound, the complex did not form and a phase separation occurred. The lowest L * was obtained by whey protein 4% and pectin 0.5% with a PH of 9. Ultimately, whey protein 4% and pectin 1% with a PH of 3 were selected as the optimum sample because of formation the strong and suitable complex. Particle size and zeta potential measurement of optimum sample, were 160 nm and -0.53 mV respectively.