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The influence of different phospholipid types (pure phospholipids 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine, POPC, 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine, DPPC, and one commercial phospholipid mixture, Lipoid H100), sterol types (cholesterol vs. β‐sitosterol), and various sterol concentrations (5–50 mol%) on liposomal membrane fluidity, thermotropic properties, liposome size, zeta potential, and lipid oxidation kinetics using fluorescent lipid probe BODIPY 581/591 C11 (4,4‐difluoro‐5‐[4‐phenyl‐1,3‐butadienyl]‐4‐bora‐3a,4a‐diaza‐s‐indacene‐3‐undecanoic acid) are investigated. DPPC bilayer is more rigid than POPC and phospholipids mixture membranes. Pure DPPC gives the smallest liposomes, while liposomes of Lipoid H100 have the largest diameter. Both sterols reduce membrane fluidity of all liposomes, increase absolute zeta potential, cause significant changes in particle size, and decrease phase transition temperature (Tm) and enthalpy of DPPC. POPC/β‐sitosterol liposomes exhibit the most significant lipid oxidation of the lipophilic probe. Along with beneficial effects of phytosterols on human health, better membrane fluidity, more favorable and stabilizing interactions with phospholipids, smaller vesicle size, and enhanced physical stability in comparison to cholesterol are some of the encouraging results for the use of β‐sitosterol in liposome formulations for potential application in foods, pharmaceutics, and cosmetics. Practical Applications: Adjusting the composition of liposomal membrane (lipid type, sterol type, and concentration) can be used as a tool to control membrane fluidity, permeability, and thermotropic properties, and thus predict release properties, physical, thermal, and oxidative stability. A commercial phospholipid mixture of different natural phospholipids with impurities creates less uniform liposomal membrane that is characterized by higher fluidity in comparison to DPPC. The type of phospholipid has huge influence on MLVs size. β‐sitosterol, which is a phytosterol with beneficial effects on human health can be used as a replacement for cholesterol in liposomal formulations, but with the following in mind: β‐sitosterol reduces fluidity of the phospholipid bilayer to a lesser extent than cholesterol, β‐sitosterol gives smaller MLVs than cholesterol, DPPC/β‐sitosterol SUVs are bigger than 100 nm in diameter (relevant for intravenous administration), MLVs with ≥30 mol% of β‐sitosterol can be considered as physically stable (unlike those with cholesterol), irrespective to the phospholipid type. The influence of different phospholipid types, sterol types, and various sterol concentrations on liposomal membrane fluidity, thermo tropic properties, liposomesize, zeta potential, and lipid oxidation kinetics are investigated.

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Carqueja (Pterospartum tridentatum) is an endemic species and various bioactive compounds have been identified in its aqueous extract. The aim of this study was to protect the natural antioxidants from the aqueous extract of carqueja by encapsulation in Ca-alginate microbeads and Ca-alginate microbeads containing 10% and 20% (w/v) of inulin. The microbeads produced by electrostatic extrusion technique had an average diameter from 625 μm to 830 μm depending on the portion of inulin. The sphericity factor of the hydrogel microbeads had values between 0.014 and 0.026, while freeze dried microbeads had irregular shape, especially those with no excipient. The reduction in microbeads size after freeze drying process (expressed as shrinkage factor) ranged from 0.338 (alginate microbeads with 20% (w/v) of inulin) to 0.523 (plain alginate microbeads). The expressed radical scavenging activity against ABTS and DPPH radicals was found to be between 30% and 40% for encapsulated extract, while the fresh extract showed around 47% and 57% of radical scavenging activity for ABTS and DPPH radicals, respectively. The correlation between antioxidant activity and the total phenolic content were found to be positive (in both assay methods, DPPH and ABTS), which indicate that the addition of inulin didn't have influence on antioxidant activity. The presence of inulin reduced stiffness of the hydrogel, and protected bead structure from collapse upon freeze-drying. Alginate-inulin beads are envisaged to be used for delivery of aqueous P. tridentatum extract in functional food products.

The influence of resveratrol encapsulated into liposomes (prepared with a commercial lipid mixture of phospholipids, phospolipon 90NG, using the thin film and proliposome methods) on the structural properties of the liposome membrane was investigated by electron paramagnetic resonance (EPR) spectroscopy, fluorescence spectroscopy, and differential scanning calorimetry. Two fluorophores and two spin probes were used to monitor the characteristics of membranes made from a commercial mixture of phosphatidylcholine. Resveratrol was positioned rather in the inner part of the liposome membranes causing reduction in membrane fluidity. Moreover, resveratrol induced a concentration-dependent decrease in the gel-to-liquid crystalline phase transition temperature (from 41.3 to 38.3°C, for a saturated 1,2-dipalmitoyl-sn-glycero-3-phospatidylcholine bilayer). The antioxidant activity of resveratrol was confirmed by its 95% inhibition of lipid peroxidation, compared to liposomes without resveratrol exposed to the same conditions. Similarly, EPR spectroscopy spin trapping showed an 87% reduction in the spectra intensity of the hydroxyethyl radical, which indicates the efficiency of resveratrol for inhibition of OH radical production.Practical applications: Resveratrol is in the limelight all over the world as a health-beneficial compound widely investigated as natural antioxidant suitable for prevention of human cardiovascular diseases and inhibition of low-density lipoproteins oxidation. Public interest in prevention of diseases through enriched staple foods grows each day. Nonetheless, addition of antioxidants to aqueous-based food can be limited due to their troublesome characteristics. Liposomes are nanocarriers that may be used to overcome the disadvantages and they can be used for food applications. Liposomes could be prepared using only natural components and therefore the new formulations could be quickly implemented. Still, the application of liposomes in food systems is not widespread due to time consuming manufacturing processes and high costs. The presented results provide marks and suggestions to food manufacturers and scientists on how to make broader use of resveratrol-loaded liposomes which add value and improve the quality of existing food products.