Improving antioxidant effect of phenolic extract of Mentha piperita using nanoencapsulation process

Abstract

In the present investigation, effect of chitosan, Alyssum homolocarpum gum (AHG) and complex (1:1) of chitosan and AHG (CCA) on the properties of nanoencapsulated Mentha piperita phenolic extract (polydispersity index (PDI), particle size, ζ-potential, encapsulation efficiency, release of phenolic compounds and evaluating effect of nanoencapsulation process on the antioxidant activity of phenolic extract of M. piperita in the soybean oil) was studied. The use of a high-pressure homogenizer, at pressure of 11,000 psi, reduced the particle size of W/O/W nanoemulsions coated with chitosan, CCA, and AHG, with a diameter of 108.66, 65.18, and 70.81 nm, respectively. Moreover, the PDI of nanoemulsions in AHG and CCA in all conditions was lower than 0.5, indicating the uniform size distribution and thus the success of the nanoparticle production process. The Intensity curve also showed that the emulsion generated by CCA had better emulsion droplets than the others due to its lower curve width and therefore greater uniformity. Also, the amount of ζ-potential of droplets of emulsions coated with chitosan, CCA and AHG were 28.69, 20.16 and − 37.4 mV, respectively. The results of the peroxide and p-anisidine test revealed that CCA extract caused the best oxidative stability in soybean oil, followed by AHG and chitosan, respectively, which were consistent with the results of the phenolic release test. Gradual and more release of phenolic compounds over time in the CCA-coated sample was superior to other samples.