ANTIMICROBIAL ACTIVITY, CITOTOXICITY, AND IRRITATION POTENTIAL OF PASSION FRUIT SEED OIL PICKERING EMULSIONS

Brazil is one of the world's largest producers of yellow passion fruit (Passiflora edulis f flavicarpa), but its seed's potential is not yet fully achieved in the production chain. This research evaluated the antimicrobial activity, cytotoxicity, and irritation potential of passion fruit seed oil Pickering emulsions. The colloidal stabilizers were Fungal Chitosan and Chitosan Hydrochloride particles produced by deprotonation. The systems were prepared by homogenizing passion fruit seed oil (5-10%) in a suspension of fungal chitosan (1%) and chitosan hydrochloride (1%) particles. The characterization of the samples applied particle size and Zeta Potential by DLS, antibacterial activity by microdilution, cytotoxicity by MTT, and irritation potential by HET-CAM. This study emulsions showed micrometer scale particles (1.3-1.84 µm) and positive Zeta potential (31.27-35.77 mV). Only the emulsion with chitosan particles and 10% passion fruit seed oil inhibited all pathogenic microorganisms tested. The same sample presented an inhibition percentage of 20.08% and 38.83% for L929 and Hacat cell cultures, respectively, in the MTT essay. These results classify this sample as non-cytotoxic and discretely cytotoxic, respectively. The remaining emulsions were non-cytotoxic since their inhibition percentages were inferior to 25%. All emulsions evaluated presented no irritation potential, as no hemorrhage, coagulation, or vessel lysis events occurred. Therefore, they may be considered biocompatible. Chitosan particles and chitosan hydrochloride were viable alternatives as stabilizers to produce passion fruit seed oil Pickering emulsions with bacterial activity. All formulations presented smaller dimensions than those reported in the literature, with high Zeta potential, indicating satisfactory stability for food application. As for antimicrobial action, the interaction of the oil with the fungal chitosan particles was more effective against the pathogenic microorganisms tested. Therefore, the emulsion with 10% OSM and stabilized with fungal chitosan particles presents better general characteristics for application in food.