Combined pulsed electric field-ultrasound assisted extraction of yarrow phenolic-rich ingredients and their nanoliposomal encapsulation for improving the oxidative stability of sesame oil

Abstract

In this research, yarrow phenolic-rich extract was produced using pulsed electric field (PEF)-ultrasound assisted technology. The highest extraction efficiency (5.99 %) was obtained at 6.25 kV/cm of PEF and the sonication time of 60 min. As the PEF intensity and sonication time rose, the total phenolic content (TPC) and ferric-reducing power (RP) of the extracts increased. The PEF intensity of 2.70 kV/cm and sonication time of 45.83 min were the optimum extraction conditions resulting in the highest extraction efficiency, TPC, and RP. Then, this optimum extract was loaded into nanoliposomes. At higher extract levels, the encapsulation efficiency lowered, while the particle size, polydispersity index (PDI), and zeta potential of the nanoliposomal samples elevated. The results of Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) confirmed the successful encapsulation of yarrow extract into nanoliposomal carriers; the sample containing the extract had the highest enthalpy (3600 J/g) and nanoliposomes loaded with yarrow antioxidant extract (0.11 mL/mg) was the optimum sample. Finally, the sesame oil containing 500 ppm free and nanoliposome extract, as well as the sample with 200 ppm BHT were evaluated for oxidative stability. The highest oxidation stability (14.21 h) belonged to the oil containing nanoliposomal yarrow phenolic extract.

Keywords

• Natural antioxidants
• Pulsed electric field
• Sonication
• Nanocarriers
• Oxidation