investigation of physicochemical, antioxidant, and antimicrobial properties of thymol and resveratrol encapsulated with zein-caseinate nanoparticle

Thymol and resveratrol are organic, phenolic compounds with wide-ranging potential applications in the food industry, mainly use as an anti-oxidation and antibacterial additives. however, their weak stability, low water solubility, and bioavailability have severely limited their industrial applications. herein, zein-casein nanoparticles loaded with thymol and resveratrol have been successfully prepared using the liquid-liquid dispersion method to empower their stability, solubility, antioxidant, and antimicrobial properties. as a result, formulation of 75% thymol with 25% resveratrol mixing ratio 1:20 (75t25r20) was the most stable nanoparticle with zeta potential of -19.54 compared to only thymol or resveratrol nanocapsules (100t0r20 and 0t100r20) with zeta potential of -1.22 and -4.12 respectively.  in addition, scavenging of 2,2-diphenyl-1-picrylhydrazyl (dpph) radical activity increased to 58.77% in 75t25r10 nanocapsule compared to the antioxidant activity of nanocapsule of only thymol or resveratrol with dpph of 20.33% and 13.67% respectively. the synergic effect of the thymol and resveratrol also improved the antimicrobial activity. for example, minimum inhibitory concentration (mic) against e.coli bacteria in culture medium, drops from 300-350 for sole thymol/resveratrol nanocampule (100t0r10, 0t100r10) to 100 for 75t25r10. finally, scanning electron microscopy (sem), and fourier transforms infrared (ft-ir) spectroscopy have been used for the physical characterization of the resultant nanoparticles (nps). it is worth mentioning that formed zein-casein nanoparticles loaded with thymol and resveratrol have good redispersibility and physical stability stored at -20 0c. therefore, this investigation introduces an excellent organic candidate for delivering hydrophobic active compounds, which is of significance in the cosmetics and especially food industries.