Formulation, development and evaluation of bifunctionalized nanoliposomes containing Trifolium resupinatum sprout methanolic extract: as effective natural antioxidants on the oxidative stability of soybean oil

Abstract Background The various extracts of Trifolium resupinatum (Persian clover) sprout was obtained by using different solvents and microwave assisted extraction in the present study. Then, the bifunctionalized nanoliposomes were prepared and added to soybean oil for evaluating their effect on deferring the oxidation process. Methods The total phenol and antioxidant activity of the extracts was determined by using the free radical scavenging assay. Then, various nanoliposomal structures of the methanolic extract of Persian clover sprout (PCSE) were prepared by using six several formulations containing different ratios of soybean oil, lecithin and the extract. Afterward, the most stable nanoliposome was bifunctionalized by using WPC and pectin (PCSEN-W and PCSEN-WP, respectively). The size and zeta potential of nanoparticles were measured. Furthermore, in order to evaluate the effects of PCSE, PCSEN, PCSEN-W and PCSEN-WP at 100–300 ppm concentrations in deferring the oxidation process of soybean oil, the heat treatment tests were applied (PV and TBA) at 63 °C within a 20-day period. Results The methanolic extract had the highest level of total phenol and antioxidant activity. The results of creaming index and microencapsulation efficiency were exhibited that formulation containing 30% oil, 5% lecithin and 2% the extract was led to the production of the most stable nanoliposomal structure (PCSEN). The size of nanoparticles was in the range of 282.5–491.2 nm. Zeta potential of the samples was obtained in the range between − 56.9 and − 36.3 mV. Polydispersity index of them was ranged from 0.424 to 0.541. The results were confirmed the existence of stable nanoliposomal systems. The results of the PV and TBA values of the extracts in free and nanoliposomal forms were shown that the nanoliposomal forms had very good antioxidant activity against the oxidation process in soybean oil.