Fabrication of enhanced aerogel template oleogels with enzyme-hydrolyzed soy protein isolate and covalent cross-linking.

In recent years, the utilization of aerogel templates in oleogels to replace animal fats has garnered considerable attention due to health concerns. This study employed a "fiber-particle core-shell nanostructure model" to combine sodium carboxymethylcellulose (CMCNa) and soy protein isolate (SPI) or SPI hydrolysate (SPIH), and freeze-dried to form aerogel template, which was then dipped into oil to induce oleogels. The results showed that adding SPIH significantly improved the physicochemical properties of oleogels. The results of ζ-potential, FTIR, and rheology demonstrated a stronger binding of SPIH to CMC-Na compared to SPI. The CMC-Na-SPIH aerogels exhibited a coarser surface and denser network structure in contrast to CMC-Na-SPI aerogels, with an oil holding capacity (OHC) of up to 84.6 % and oil absorption capacity (OAC) of 47.4 g/g. The mechanical strength of oleogels was further enhanced through chemical crosslinking. Both CMC-Na-SPI and CMC-Na-SPIH oleogels displayed excellent elasticity and reversible compressibility, with CMC-Na-SPIH oleogels demonstrating superior mechanical strength. Additionally, CMC-Na-SPIH oleogels exhibited enhanced slow release of antimicrobial substances and antioxidant properties. Increasing the content of SPI/SPIH significantly improved the mechanical strength, antioxidant capacity, and OHC of the oleogels. This research presents a straightforward and promising approach to enhance the performance of aerogel template oleogels.

Effects of drying method and oil type on edible polyunsaturated oleogels co-structured by hydroxylpropyl methyl cellulose and xanthan gum.

The subtle balance between the interactions of polysaccharide molecules and the interactions of polysaccharide molecules with oil molecules is significantly important for developing polysaccharide-based polyunsaturated oleogels. Here, hydroxylpropyl methyl cellulose and xanthan gum were used to structure edible oleogels via emulsion-template methodology, while the effects of drying methods (hot-air drying (AD) and vacuum-freeze drying (FD)) and oil types (walnut, flaxseed and Moringa seed oil) on the structure, oil binding capacity (OBC), rheological properties, thermal behaviors and stability of oleogels were specially investigated. Compared with AD oleogels, FD oleogels exhibited significantly better OBC, enhanced gelation strength (G' value) and better capacity to holding oil after high temperature processing, which was attributed to the possibly increased oil-polysaccharide interactions. However, the weakened polysaccharide-polysaccharide interactions in FD oleogels failed in providing stronger physical interface or enough rigidity to restrict the migration of oil molecules. Polyunsaturated triacylglycerols in vegetable oils deeply participated in the construction of the network of AD oleogels through weak intermolecular non-covalent interactions, which in turn greatly changed the crystallization and melting behaviors of vegetables oils. In brief, this research may provide useful information for the development of polysaccharide-based polyunsaturated oil oleogels.

Foam-templated oleogels constructed by whey protein isolate and xanthan gum: Multiple-effect delivery vehicle for Antarctic krill oil.

To address the limitations of Antarctic krill oil (AKO) such as easy oxidation, unacceptable fishy flavor and low bioaccessibility of astaxanthin in it, a multiple-effect delivery vehicle for AKO is needed. In this study, whey protein isolate (WPI) and xanthan gum (XG) were utilized to construct AKO into oleogels by generating foam-templates. The effects of the concentration of XG on the properties of foam, cryogel and the corresponding oleogels were investigated, and the formation mechanism of oleogel was discussed from the perspective of the correlation between foam-cryogel-oleogel. The results demonstrated that with the increase of the concentration of XG, the foam stability was improved, the cryogel after freeze drying had a more uniform network structure and superior oil absorption ability, and the corresponding oleogel had excellent oil holding ability after oil absorption. The AKO oleogels showed superior oxidative stability compared with AKO. The in vitro digestion experiments demonstrated that the bioaccessibility of the astaxanthin in this oleogel was also considerably higher than that in AKO. In addition, this oleogel had masking effect on the odor-presenting substances in AKO, while retaining other flavors of AKO. The foam-templated oleogel can be considered as a multiple-effect vehicle for AKO to facilitate its application in food products. This study provides theoretical basis and data support for the development and utilization of novel vehicle for AKO, broadening the application of AKO in the field of food science.

Recent advances on food-grade oleogels: Fabrication, application and research trends.

In order to improve the nutritional and quality characteristics of food, solid fats are widely used in food formulations. With the continuous improvement of consumers' awareness of health in recent years, substantial attempts have been carried out to find substitutes for solid fats to reduce saturated fatty acid content in foods. Oleogels have drawn increasing attention due to their attractive advantages such as easy fabrication, superior fatty acid composition and safe use in food products to satisfy consumers' demands for healthy products. This review provides the latest information on the diversified oleogel systems. The feasibility of oleogel and oleogel-based system as nutraceutical vehicles is elucidated. The type as well as concentration of oleogelators and the synergistic effect between two or more oleogelators are important factors affecting the properties of obtained oleogel. Oleogels used in nutraceutical delivery have been shown to offer increased loading amount, enhanced bioaccessibility and targeted or controlled release. These nutrients wrapped in oleogels may in turn affect the formation and properties of oleogels. Furthermore, the future perspectives of oleogels are discussed. The feasible research trends of food-grade oleogel include oleogel-based solid lipid particle, essential oil-in-oleogel system, delivery of probiotics, nutraceuticals co-delivery and microencapsulated oleogel.

Development of Chocolates with Improved Lipid Profile by Replacing Cocoa Butter with an Oleogel.

The reformulation of chocolates seeks to find innovative alternatives to cocoa butter (CB) that are more economical and adhere to nutritional recommendations to replace saturated fats with unsaturated ones. In this research, chocolates were elaborated by substituting CB with an oleogel (OG) formulated with hydroxypropyl methylcellulose (HPMC) as an entrapper of sunflower oil by using the foam-templated approach. Four different CB/OG blends were prepared and characterized as potential CB substitutes (100/0 control), at replacement levels of 30%, 50%, 70% and 100% (70/30, 50/50, 30/70 and 0/100 blends), and subsequently, CB/OG-based chocolates (CB/OG-Ch) were formulated (100/0-Ch, 70/30-Ch, 50/50-Ch, 30/70-Ch and 0/100-Ch). Both the CB/OG blends and the CB/OG-Ch counterparts were characterized by dynamic and stationary rheology, hardness, thermal parameters, microstructure, and oil-binding capacity; in addition, the lipid profile of the chocolates was analyzed, and a sensory analysis was performed. Increasing the OG proportion in the CB/OG blend weakens the rigidity and strength of the fat-crystal network conferred by the CB, and decreases both its viscoelasticity and thermal parameters, but the differences between all the different properties and parameters of the CB/OG-Ch samples diminished in presence of the other ingredients used in the chocolate formulation. Sensory analysis evidenced that it is possible to replace up to 70% of CB with the OG, although from a technological point of view a replacement level of 50% would seem more appropriate. As compared to 100/0-Ch, 50/50-Ch and 30/70-Ch involve saturated fat reductions of 55% and 37%, respectively.

Thermorheological Characterization of Healthier Reduced-Fat Cocoa Butter Formulated by Substitution with a Hydroxypropyl Methylcellulose (HPMC)-Based Oleogel.

Cocoa butter (CB) is a main ingredient in pastry due to the unique functional properties of its fat, which is high in saturated fatty acids (SFAs). However, excessive consumption of SFAs is associated with the occurrence of several chronic diseases. This study researched the partial or total replacement of CB by an oleogel (OG) formulated with a healthier lipid profile, for mixed systems that would allow a partial substitution of CB in confectionery products. The "emulsion-templated approach" was used to develop a sunflower oil-HPMC-based OG. Different CB:OG ratios were formulated increasing the percentage replacement of CB by OG from 50 to 100%. Rheological and textural properties were determined and compared with a CB control at 20 and 10 °C. Oil-binding capacity was also analyzed. The systems showed a solid-like behavior, with higher elastic than viscous modulus, which increased with CB concentration. Compared with 20 °C, at 10 °C there was an increase in connectivity, viscoelasticity, and consistency of the systems, in response to a more complete CB crystallization. The replaced systems also presented a better lipid profile than CB. This evidence suggests that formulated CB:OG system at 50:50 ratio could become useful as a CB equivalent in chocolate products.

Effects of thickening agents on the formation and properties of edible oleogels based on hydroxypropyl methyl cellulose.

Emulsion-templated approach was adopted to obtain edible oleogels using hydroxypropyl methyl cellulose (HPMC) as the main emulsifier in combination with the usage of thickening agents such as carboxymethyl cellulose (CMC), xanthan gum, sodium alginate, arabic gum, guar gum, flaxseed gum or locust bean gum. Polarized light microscopy (PLM) and rheological measurements were carried out to investigate the microstructure and mechanical strength of emulsions and their corresponding oleogels, respectively. X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) analyses were employed to study the interaction between polysaccharides. Gel strength and oil binding capacity of oleogels were related to the mechanical strength of emulsions as well as to the network of soft solids. Oleogels with semi-crystalline structure were formed by the binding of liquid oil to polysaccharides, which were stabilized by the intramolecular or intermolecular molecular hydrogen bonds between polysaccharides.