Protective effect of surfactant modified phytosterol oleogels on loaded curcumin

β-carotene and resveratrol loaded glycerol monostearate-based oleogels: Physicochemical characterization at low gelation concentrations

Oleogels are semi-solid systems that can function both as replacers of trans and saturated fats and/or as carriers of lipophilic bioactive compounds. However, bioactive compounds can affect the structure of the oleogel matrix and this effect depends on the properties of such compounds. Therefore, the aim of this study was to develop oleogels loaded with β-carotene (BC) or resveratrol (R), with low concentrations of glycerol monostearate (GMS, 2-5 wt%) and sunflower oil as organic solvent. The gels were characterized by polarized light microscopy, rheological measurements, differential scanning calorimetry, oil binding capacity and Fourier transform infrared spectroscopy. At higher GMS concentrations, stronger oleogels and higher temperatures associated with transitions (sol-gel/gel-sol and crystallization/melting) were observed. The incorporation of bioactive compounds modified the gelation behavior. BC weakened the oleogel structure during the transient molecular organization of GMS, whereas R increased the dynamic moduli. BC also caused slight oil release at lower concentrations, while R improved retention. The high hydrophobicity of BC may be disturbing the solubility balance of the system, while R has phenolic hydroxyl groups that may strengthen hydrogen bonds. However, there were no considerable changes in mechanical properties after storage. We hypothesize that the molecular organization of GMS over time may be masking the modifications that bioactive compounds cause in mechanical properties. In fact, changes in the structure were revealed, as the addition of BC or R changed the morphology of the three-dimensional network crystals. Thus, the results can contribute to the rational choice of system components using low concentrations of oleogelator, as the composition of the bioactive compound exerts influence on the modulation of lipid matrices.

Formation, characterization, and application of natural bioactive phytosterol-based oleogels: A review

Oleogels are innovative structured fat systems that can replace detrimental lipids and saturated fats. Among the various gelators used to construct oleogels, phytosterols are regarded as potential oleogelators due to ability to lower blood cholesterol levels and protect patients from cardiovascular illnesses, although little research has been conducted on phytosterols. This article examines the formation, characterization, and application of phytosterol-based oleogels in detail. The oleogelation behaviors of phytosterol-based oleogels are affected by their formulation, which includes phytosterol type, combined oleogelator, proportion, concentration and oil type. These oleogels exhibit potential applications as solid fat substitutes without affecting the texture or sensory properties of food products or as effective delivery vehicles. To encourage the research and implementation of phytosterol-based oleogels, we will ultimately not only highlight problems related to their use in food processing, but also provide a few viewpoints, with the goal of providing fresh insights for advancing trends.

Effect of different gelators on the physicochemical properties and microstructure of coconut oleogels

BACKGROUND

The inherent properties of coconut oil (CO), including its elevated saturated fatty acid content and low melting point, make it suitable for application in plastic fat processing. The present study explores the physicochemical characteristics, micromorphology and oxidative stability of oleogels produced from CO using various gelators [ethylcellulose (EC), β-sitosterol/γ-oryzanol (PS) and glyceryl monostearate (MG)] to elucidate the formation mechanisms of coconut oleogels (EC-COO, PS-COO and MG-COO).

RESULTS

Three oleogel systems exhibited a solid-like behavior, with the formation of crystalline forms dominated by β and β'. Among them, PS-COO exhibited enhanced capability with respect to immobilizing liquid oils, resulting in solidification with high oil-binding capacity, moderate hardness and good elasticity. By contrast, MG-COO demonstrated inferior stability compared to PS-COO and EC-COO. Furthermore, MG-COO and PS-COO demonstrated antioxidant properties against CO oxidation, whereas EC-COO exhibited the opposite effect. PS-COO and EC-COO exhibited superior thermodynamic behavior compared to MG-COO.

CONCLUSION

Three oleogels based on CO were successfully prepared. The mechanical strength, storage modulus and thermodynamic stability of the CO oleogel exhibited concentration dependence with increasing gelling agent addition. PS-COO demonstrated relatively robust oil-binding capacity and oxidative stability, particularly with a 15% PS addition. This information contributes to a deeper understanding of CO-based oleogels and offers theoretical insights for their application in food products. © 2024 Society of Chemical Industry.