Building blocks of β-sitosterol-γ-oryzanol gels revealed by small-angle neutron scattering and real space modelling

Effect of different oleogelators on physicochemical properties, oxidative stability and astaxanthin delivery of macadamia oil-based oleogels

Oleogels can be formed using different types of oleogelator, which lead to different end properties. In this study, four kinds of oleogelators, rice bran wax (RBW), monoglyceride stearate (MG), beeswax (BW), and a mixture of β-sitosterol and γ-oryzanol (SO) were used to prepare astaxanthin-loaded macadamia oil-based oleogels. Fourier transform infrared spectroscopy, polarized light microscopy, X-ray diffraction, differential scanning calorimetry, and dynamic shear rheometry were then used to evaluate the effects of the different oleogelators and astaxanthin on the physicochemical properties of the oleogels. The results showed that van der Waals forces played a key role in the formation of all the oleogels, while hydrogen bonding was also important for the SO- and MG-based oleogels. Moreover, astaxanthin addition did not change the crystal morphology and intramolecular interaction forces of the oleogels, but it did increase their oxidative stability and decrease their thermal stability, hardness, and oil-binding properties. In addition, the digestive behavior of the oleogels was evaluated using a three-stage in vitro gastrointestinal model. All the oleogelators significantly affected the lipolysis of the macadamia oil and the bioaccessibility of the astaxanthin, with the degree of lipolysis being positively correlated to the bioaccessibility. MG-based oleogels were the most effective at increasing the bioaccessibility of the astaxanthin.

Effect of γ-oryzanol/β-sitosterol-based oleogels on the physicochemical and gel properties of Nemipterus virgatus myofibrillar protein

BACKGROUND

The effect of oleogels prepared with peanut oil and different concentrations of γ-oryzanol and β-sitosterol mixture (γ/β; 20, 40, 60, 80 and 100 g kg-1) on the physicochemical and gel properties of myofibrillar protein (MP) was investigated.

RESULTS

The solubility and average particle size of MP first decreased and then increased with increasing γ/β concentration. Peanut oil or oleogels could induce the exposure of hydrophobic amino acids and the unfolding of MP, thus significantly increasing the surface hydrophobicity, sulfhydryl content and absolute value of zeta potential, which reached maximum values when the γ/β concentration was 60 g kg-1 (P < 0.05). The addition of peanut oil decreased the gel strength and water holding capacity of MP gel. However, oleogels prepared with 60 g kg-1 γ/β could significantly increase the hydrophobic interactions and disulfide bond content of MP gel (P < 0.05), which promoted the crosslinking and aggregation of MP, enhancing the gel properties. Peanut oil had no significant influence on the secondary structure of MP, while oleogels promoted the transition of MP conformation from α-helix to β-sheet structure. The results of light microscopy and confocal laser scanning microscopy indicated that oleogels prepared with 60 g kg-1 γ/β filled in the pores of MP gel network to form denser and more uniform structure.

CONCLUSION

Oleogels prepared with 60 g kg-1 γ/β could effectively improve the quality of MP gel and have promising application prospects in surimi products. © 2024 Society of Chemical Industry.

Natural Products from Herbal Medicine Self-Assemble into Advanced Bioactive Materials

Novel biomaterials are becoming more crucial in treating human diseases. However, many materials require complex artificial modifications and synthesis, leading to potential difficulties in preparation, side effects, and clinical translation. Recently, significant progress has been achieved in terms of direct self-assembly of natural products from herbal medicine (NPHM), an important source for novel medications, resulting in a wide range of bioactive supramolecular materials including gels, and nanoparticles. The NPHM-based supramolecular bioactive materials are produced from renewable resources, are simple to prepare, and have demonstrated multi-functionality including slow-release, smart-responsive release, and especially possess powerful biological effects to treat various diseases. In this review, NPHM-based supramolecular bioactive materials have been revealed as an emerging, revolutionary, and promising strategy. The development, advantages, and limitations of NPHM, as well as the advantageous position of NPHM-based materials, are first reviewed. Subsequently, a systematic and comprehensive analysis of the self-assembly strategies specific to seven major classes of NPHM is highlighted. Insights into the influence of NPHM structural features on the formation of supramolecular materials are also provided. Finally, the drivers and preparations are summarized, emphasizing the biomedical applications, future scientific challenges, and opportunities, with the hope of igniting inspiration for future research and applications.

Comparison of diosgenin-vegetable oils oleogels with various unsaturated fatty acids: Physicochemical properties, in-vitro digestion, and potential mechanism

This study aimed to evaluate the influence of gelation and unsaturated fatty acids on the reduced extent of lipolysis between diosgenin (DSG)-based oleogels and oils with various unsaturated fatty acids. Overall, the lipolysis of oleogels was significantly lower than oils. The highest reduced extent of lipolysis (46.23 %) was obtained in linseed oleogels (LOG) while sesame oleogels possessed the lowest (21.17 %). It was suggested LOG discovered the strong van der Waals force to induce the robust gel strength and tight cross-linked network and then increase the contact difficulty between lipase and oils. Correlation analysis revealed that C18:3n-3 was positively correlated with hardness and G' while C18:2n-6 was negative. Thus, the effect on the reduced extent of lipolysis with abundant C18:3n-3 was most significant while that rich in C18:2n-6 was least. These discoveries provided a deepening insight into DSG-based oleogels with various unsaturated fatty acids to design desirable properties.

Controlled volatile release from β-sitosterol-based oleogels based on different self-assembly mechanisms

This study examined how the self-assembly mechanisms of β-sitosterol-based oleogels influenced the release of volatile compounds. Microscopy, X-ray diffraction (XRD) and small-angle X-ray scattering (SAXS) measurements showed that the three β-sitosterol-based oleogels (β-sitosterol + γ-oryzanol oleogels (SO), β-sitosterol + lecithin oleogels (SL) and β-sitosterol + monostearate oleogels (SM)) had significant differences in their microstructures, which were formed via different self-assembly mechanisms. SO exhibited the highest oil binding capacity (OBC), complex modulus (G*) and apparent viscosity. Dynamic and static headspace analyses suggested that network structure of β-sitosterol-based oleogels affected the release of volatile components. SO showed the strongest retention effect, followed by SL and SM. The release of volatile compounds mainly related to structural strength and compositions of oleogels. These results indicated that β-sitosterol-based oleogels formed with different self-assembly mechanisms have the potential to serve as effective delivery systems for controlling the release of volatile compounds.