Interaction of camellianin A and lysozyme: Binding mechanism and its application in nanoemulsions

The interaction of camellianin A (CA) and lysozyme (LYS) was analyzed by spectrofluorimetry and molecular docking methods. The nanoemulsions stabilized by CA and LYS were ultrasound-assisted constructed, and characterized. The fluorescence result indicated that CA and LYS could spontaneously form supramolecular complexes driven by van der Waals forces and hydrogen bonds, which coincided with molecular docking analysis. CA and LYS could synergistically reduce the O/W interfacial tension, and stabilize nanoemulsions. The CA-LYS nanoemulsion with the average droplet size of 212.91 ± 1.21 nm could be obtained at the following ultrasonic homogenization conditions: CA/LYS ratio, 1:2; CA-LYS concentration, 0.426 %; ultrasonic time, 5 min; ultrasonic power, 660 W. The obtained nanoemulsion could effectively protect lutein against UV, and inhibit lipid oxidation. It demonstrated strong stability in acidic, neutral, and high-temperature environments; however, its stability was compromised under alkaline and high ionic strength conditions. Our results can prompt the development of new food-graded nanoemulsions.