Robust stability and antimicrobial activity of D-limonene nanoemulsion by sodium caseinate and high pressure homogenization

Sodium caseinate (SC) derived from milk casein has excellent stability and emulsification properties. In this study, SC-stabilized D-limonene nanoemulsions were prepared for the first time by high pressure homogenization technique. Based on optimal conditions, the D-limonene nanoemulsions had the smallest particle size (d = 130 nm) and the highest negative surface potential. After placed at 4 degrees C for 60 days and heated at 90 degrees C for 1 h, the prepared nanoemulsions maintained their original particle sizes, indicating a high storage and thermal stability. In addition, the antibacterial activity of D-limonene against S. aureus was significantly increased by 5-fold after SC encapsulation. These results indicated that SC could be an outstanding natural component for stabilizing nanoemulsions to improve hydrophobic actives in food applications.

Automated summary

In this study, SC-stabilized D-limonene nanoemulsions were prepared for the first time using high pressure homogenization technique. The nanoemulsions exhibited the smallest particle size and the highest negative surface potential, and showed high storage and thermal stability. Furthermore, SC encapsulation significantly enhanced the antibacterial activity of D-limonene.