Proceedings of International Congress on Bioactive Compounds and International Workshop on Bioactive Compounds
Proceedings of 2nd International Congress on Bioactive Compounds

Passion fruit seed is a valuable by-product from the food industry, a source of oil with many well-studied properties. Vegetable oils, like passion fruit seed oil (PFSO), present a wide range of bioactive compounds that may act as antimicrobial agents in food products. Nevertheless, these raw materials may undergo oxidation if not protected from environmental factors like light and heat. An alternative to protect these substances, control their release, and improve their solubility and bioavailability is dispersion in an emulsion. Nanoemulsions represent a potential carrier for bioactive substances application in food. Formulation stabilized by biopolymers, such as chitosan hydrochloride, a water-soluble chitosan derivative, has been gaining attention in the production of the colloidal systems. Therefore, this study aimed to develop passion fruit seed oil nanoemulsions stabilized by chitosan hydrochloride and evaluate their antimicrobial activity. Nanoemulsions production followed the phase inversion technique, applying different chitosan hydrochloride concentrations (0.5% and 1.0%) (PFSO-NE0.5% and PFSO-NE1%), fixed PFSO concentration (6%), and Tween 80 (6%) as cosurfactant. The nanoemulsion particles' characterization involved Dynamic Light Scattering (DLS) and Zeta Potential. in vitro antibacterial and antifungal activities of the nanoemulsions followed the minimum inhibitory concentrations (MIC) by the microdilution technique against the bacteria Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, Bacillus cereus, Enterobacter faecium, and Listeria monocytogenes, and the fungi Aspergillus niger and Colletotrichum siamense, respectively. PFSO-NE0.5% displayed a small particle size (137.73±1.78 nm), positive zeta potential (+22.60±0.26 mV), polydispersity index of 0.52±0.01, and homogeneous visual appearance. PFSO-NE1.0% displayed a smaller particle size (103.72±4.05 nm), positive zeta potential (+15.67±0.99 mV), low polydispersity index (0.47±0.01), and also with homogeneous visual appearance. PFSO-NE0.5% inhibited the growth of all tested bacteria (6 mg mL-1), except B. cereus. PFSO-NE1.0% prevented all bacterial growth. Despite PFSO-NE1.0% managing to avoid B. cereus proliferation, PFSO-NE0.5% required smaller concentrations to constrain S. typhimurium and S. aureus. Both nanoemulsions presented antifungal activity against A. niger and C. siamense (6 mg mL-1). Passion fruit seed oil nanoemulsion represents an alternative as a natural antimicrobial agent with potential application in multiple food products. This oil's utilization reinforces sustainability in the food chain, adds value to fruit production, and contributes to developing safer and more natural food products.