Carnauba Wax and Beeswax as Structuring Agents for Water-in-Oleogel Emulsions without Added Emulsifiers

Utilization of potassium carbonate-olive oil solutions for wax removal from fruits: Investigation of mode of action using a model gelatin-based film system

This study evaluated a potassium carbonate-olive oil solution's efficacy in removing a wax from gelatin films (model surfaces). The solution (pH 12.15-12.40) was most effective with 1 % olive oil. Dipping treatment increased wax-free film thickness by 89 % and wax-containing films by 36 %, while reducing density by 50 % and 21 %, respectively. Optical analysis confirmed wax removal, showing a 20 % drop in whiteness and 144 % higher opacity in wax-containing films. Thermal analysis revealed a 35 % lower wax melting enthalpy and 28 % less mass loss in treated films. FTIR spectra showed reduced ester CO peak intensity (1735 cm-1), confirming hydrolysis. Post-treatment, the solution's particle size grew to 2138 nm, zeta potential fell to 20.4 mV, and surface tension dropped to 40.94 mN/m. Microscopy revealed increased particle aggregation with wax-containing films. These results demonstrate the potassium carbonate-olive oil solution's effectiveness in wax removal from gelatin film surfaces through hydrolysis, emulsification, and solubilization mechanisms.

Enhancing the vegetable waxes gelation power in the presence of high-intensity ultrasound

The structuration of oils offers a promising alternative to high-saturated fats, capturing significant interest and undergoing development for two decades. Integrating high-intensity ultrasound (HIU) with oil structuration presents a compelling approach, as HIU has demonstrated its ability to alter numerous physical properties of fats with low saturated content. The primary aim of this study was to assess the impact of HIU on beeswax (BEW), candelilla wax (CLW), carnauba wax (CBW), and rice bran wax (RBW) oleogels. The minimum concentration required for oleogel formation (Cg) was established as the concentration at which the gel could maintain its structure without flowing when inverted. All oleogels in their Cg underwent sonication using a 13 mm probe, 50 % amplitude for 10s. The oleogels, whether sonicated or not, were evaluated based on their microstructure, hardness, viscoelastic properties, oil binding capacity (OBC), melting behavior, mild-infrared analysis, and X-ray. The amount of wax used to form a gel was quite low, especially for BEW (1.7 %) and CLW (1.4 %). After sonication, BEW, CLW, and CRW waxes significantly improved, mostly physical properties evaluated. On the contrary, RBW showed a depletory effect of physical properties after sonication in the condition tested. It was possible to observe that when appropriately optimized, sonication serves as a vital technique in the oleogelation of some waxes, offering a robust method to produce enhanced and stable oleogels suitable for food applications.

Quercetin-loaded candelilla wax/sunflower oil oleogels: Structural, sensory, and storage properties, and application as fat replacer in emulsion-type sausage

Replacing animal fat with vegetable oil can lower saturated fat levels in meat products; however, it may compromise their texture and flavor. In addition, vegetable oil is susceptible to oxidation. Quercetin is a lipophilic substance with antioxidant properties. We investigated the role of quercetin-loaded candelilla wax (CW)/sunflower oil-based oleogels as fat substitutes in sausages, focusing on shelf life and product quality. CW/sunflower oil oleogels containing quercetin (0.02, 0.04, and 0.06 %, w/w) were prepared and analyzed for structural, physicochemical, and antioxidant characteristics. Quercetin-loaded oleogels showed improved oil-binding capacity and rheological behavior without altering the gel structure. Notably, the oleogel containing 0.06 % quercetin exhibited the highest resistance to oxidation (P < 0.05). These oleogel-containing sausages exhibited markedly lower lipid oxidation and protein degradation, while maintaining structural integrity and sensory quality. Our data indicate that quercetin-loaded oleogels are a promising solution for reducing saturated fat and extending the shelf life of meat products.

Development and Characterization of Palm Oil-Based Oleogels Using Beeswax and Carnauba Wax as Healthier Beef Fat Mimetics

Animal fat crucially provides flavor, texture, and overall mouthfeel in meat products. However, its high saturated fatty acids (SFAs) levels present notable health risks, highlighting the need for healthier fat alternatives that maintain product quality. This study explored the potential of palm oil (PO)-based oleogel as an alternative to beef fat (BF). Specifically, two PO-based oleogels were formulated; one comprising PO and another comprising a mixed oil-based oleogel (MOG) of palm (66%), olive (12%), and linseed oils (22%). Beeswax (BW) and carnauba wax (CAW) were used as oleogelators at concentrations of 5%, 7.5%, and 10% w/w. Physicochemical properties and fatty acid composition were assessed against BF. In general, although there were differences in color and oxidative stability, the textural and thermal characteristics of PO-based oleogels showed notable similarities to BF. Additionally, MOG demonstrated a significantly (p < 0.05) improved fatty acid profile and better health indices compared to BF, characterized by reduced SFA content and increased levels of polyunsaturated fatty acids. In terms of oleogelator, oleogels formulated with higher concentrations of CAW exhibited a more compact microstructure, enhanced hardness, greater thermal stability, and increased susceptibility to lipid oxidation. In contrast, BW-based oleogels were characterized by a softer texture. The findings highlighted the potential of PO-based oleogels as a healthier alternative to traditional animal fats. PRACTICAL APPLICATION: Animal fat enhances flavor and texture in meat products but poses health risks due to high saturated fat content. This study explored palm oil-based oleogels as healthier alternatives to beef fat, aiming to mimic fat characteristics while improving health profiles. Using beeswax and carnauba wax as oleogelators, the oleogels demonstrated similarities to beef fat in certain properties while achieving improved fatty acid profiles and lower atherogenic and thrombogenic indices compared to beef fat. These findings highlight the potential of palm oil-based oleogels as innovative and health-conscious fat alternatives, aligning with consumer demands for healthier and more sustainable dietary options.

Fabrication and characterization of oleogels stabilized by pea protein-curdlan microgels

The objective of this research was to create a food-grade oleogel as an alternative to traditional solid fats, with lower levels of trans and saturated fatty acids. Oleogels with a 30 % oil concentration were successfully prepared using pea protein isolate (PPI)-curdlan (CD) microgels via an emulsion-templating method. The PPI-CD microgels, with diameters ranging from 325 to 375 nm, demonstrated excellent emulsifying properties. After centrifugation at 10,000 rpm for 15 min, the oleogels retained approximately 98 % of the oil, showing strong oil-binding capacity. Confocal laser scanning microscopy (CLSM) revealed that the oil domains were effectively trapped within a dense, interconnected protein network, indicating good structural stability. Rheological analysis indicated that the PPI-CD-stabilized oleogels exhibited significantly higher gel strength, viscoelasticity, and thixotropic recovery than oleogels stabilized by PPI alone. These oleogels showed high recovery rates (55-97 %) after shear stress, suggesting strong self-healing capabilities. Thermal analysis through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) confirmed that the oleogels had good thermal stability, further supporting their potential for use in food products. This study highlights the promise of PPI-CD microgels as a healthier alternative to traditional solid fats in food formulations.

Development and characterization of bigel systems as carriers for thyme essential oil utilizing hydrogel from chicken processing by-products for food applications

A chicken protein hydrogel (HG) was enzymatically prepared and blended with a carnauba wax-based oleogel (OG) to form bigels (BG) in ratios of 50:50 to 90:10. These systems were infused with thyme essential oil (TEO) at 0.5 %, 1 %, and 2 % v/v to harness its antioxidant properties. Polarized light microscopy revealed that carnauba wax crystals were tightly arranged in thin, plate-like structures, while the HG exhibited a completely amorphous form. FT-IR analysis indicated that OH bonds in the HG and CH bonds in cycloalkanes from the OG contributed to the stability and strength of the gels. Unlike the biphasic gels, both the OG and HG samples experienced structural disintegration when the applied strain reached approximately 30 %. HG samples, with an onset melting temperature of 59.18 °C, were particularly susceptible to thermal deformation, leading to coalescence and destabilization of the BG due to the HG phase in the composite matrix. Regardless of the TEO concentrations, the BG (50:50) demonstrated the highest water-holding capacity (60.83 %), and oil-binding capacity (99.23 %) compared to the single biopolymer gels. The lightness of the BG increased as the HG ratio increased. Additionally, the antioxidant capacity increased with higher TEO concentrations, demonstrating the gels' potential for food applications.

Surfactant-free W/O high internal phase emulsions co-stabilized by beeswax and phytosterol crystal scaffold: A promising fat mimetic with enhanced mechanical and mouthfeel properties

Water-in-oil high internal phase emulsions (W/O-HIPEs) typically rely on large amounts of surfactants to disperse water droplets and usually use crystalline saturated triacylglycerides (TAGs) to enhance processing properties. However, these practices conflict with consumer demands for 'natural' ingredients. This study seeks to develop novel crystal fractions similar to saturated TAGs for the preparation of W/O-HIPEs as low-calorie fat mimetics, focusing on their mechanical and mouthfeel properties, which have received little attention thus far. This study explored using an all-nature crystal scaffold to stabilize W/O-HIPEs as fat mimetics under surfactant-free conditions, featuring multi-sensorial attributes. The crystal scaffold was designed by varying the ratios (10:0, 8:2, 6:4, 4:6, 2:8, and 0:10, w/w) of beeswax (BW) and phytosterol (PS), two sustainable crystal fractions. The optimal stabilization of W/O-HIPEs (φ = 0.75) was achieved at a BW/PS ratio of 6:4, with only a slight increment in droplet size for either static storage (30 days) or freeze-thaw (3 cycles) treatment. Crystal particles of BW and PS performed a synergistic effect to stabilize W/O-HIPEs by forming a network in the bulk phase and adsorbing onto droplet surfaces as a Pickering stabilizer. The crystalline layer on the droplet surfaces also generated bridging networks, providing a dual stabilization mechanism for W/O-HIPEs. Incorporating 3.0 wt% of BW and PS (BW/PS = 6:4, w/w), W/O-HIPEs exhibited the required modulus of 1 × 105 Pa to mimic fat. Moreover, these W/O-HIPEs exhibited superior lubrication behavior (friction coefficients below 0.06) compared to pure liquid oil at low sliding speeds (0-2.5 mm/s), enhancing mouthfeel. However, increasing the BW and PS crystals content to 4.0 wt% led to increased brittleness, with a reduction in the emulsion's lubricity at the hydrodynamic region. These findings highlight the potential of natural crystals to develop low-calorie W/O-HIPEs as fat mimetics in the food industry.

Egg White-Based Gels with Candelilla Wax: A Study of Rheological, Mechanical, Calorimetric and Microstructural Properties

Bigels (BGs) are innovative composite systems that integrate oleogel and hydrogel structures, and are gaining increasing attention for their unique textural and functional properties in food applications. This study evaluated the rheological and mechanical properties of egg white-based bigels incorporating candelilla wax (CW) as an oleogelator. The results indicate that different egg white protein (EWP) (5-10%) concentrations and hydrogel-to-oleogel ratios (20:80 to 80:20) significantly influenced the structural and functional properties of the bigels. Compression testing revealed no significant differences in strength across the tested range; however, higher EWP concentrations enhanced the stability of the BGs. Furthermore, increased candelilla wax oleogel (CWO) content (60%) markedly improved emulsion stability, resulting in superior strength, as confirmed by dynamic light scattering. Rheological studies demonstrated shear-thinning behavior, particularly at higher hydrogel content related to the oleogel (W/O), which exhibited the highest yield stress. Microstructural investigations confirmed the presence of a continuous oleogel phase within the bigels (W/O) and revealed the formation of a complex structure. These findings suggest that a reduced hydrogel-to-oleogel ratio can be utilized across various food systems, opening new possibilities for creating customized food structures with desirable textural and functional attributes.

New Technology of Rumen-Protected Bypass Lysine Encapsulated in Lipid Matrix of Beeswax and Carnauba Wax and Natural Tannin Blended for Ruminant Diets

Tannins are compounds present in forage plants that, in small quantities in the diet of ruminants, produce protein complexes that promote passage through the rumen and use in the intestine. This study tested the hypothesis that beeswax (BW) and carnauba wax (CW) lipid matrices are effective encapsulants for creating bypass lysine (Lys) for ruminants, with tannin extracted from the Mimosa tenuiflora hay source enhancing material protection. Microencapsulated systems were made using the fusion-emulsification technique with a 2:1 shell-to-core ratio and four tannin levels (0%, 1%, 2%; 3%). The following eight treatments were tested: BWLys0%, BWLys1%, BWLys2%, BWLys3%, CWLys0%, CWLys1%, CWLys2%, and CWLys3%. Tannin inclusion improved microencapsulation yield and efficiency. CWLys3% had the highest microencapsulation efficiency and retained Lys. Lysine in BW and CW matrices showed higher thermal stability than in its free form. Material retention was greater in BW than CW. Rumen pH and temperature remained unaffected, indicating that BW and CW as the shell and tannin as the adjuvant are efficient encapsulants for Lys bypass production. The formulation CWLys3% is recommended as it is more efficient in protecting the lysin amino acid from rumen degradation.

The relationship between nonlinear viscoelasticity and baking performance in low-saturated puff pastry margarine

The oil phase obtained by blending and oleogel methods has potential for the production of non‑hydrogenated and low-saturated puff pastry margarine, thereby reducing intakes of both types of dietary fat. The crystal form, microstructure, rheology, and baking applications of puff pastry margarines prepared with anhydrous milk fat (AMF)/palm stearin (POs), POs/palm oil (PO), beef tallow (BT)/PO, or AMF/POs/diacetyl tartaric acid ester of mono(di)glycerides (DATEM) oleogels were investigated using X-ray scattering, polarized light microscope, and rheometer, respectively. All margarines exhibited β'-form crystal and strongly viscoelastic at low strain. With the addition of DATEM oleogel, their crystal microstructure became more uniform and finer, and the croissants were less hard (1690) and chewiness (160). The chewiness of croissants produced using the margarines was significantly improved with POs content. The theoretical basis for preparation and application in non‑hydrogenated and low-saturated puff pastry margarine was provided in the present study.

Multiscale analysis of triglycerides using X-ray scattering: implementing a shape-dependent model for CNP characterization

In the last decade, research has focused on examining the fundamental interactions occurring in triglycerides, aiming to comprehend the self-assembly of crystalline nanoplatelets (CNPs) and their role in forming larger hierarchical structures essential for fat functionality. Microscopy research on CNPs frequently requires disruptive preparatory techniques, such as deoiling and sonication, to achieve quantitative outcomes. Conversely, X-ray scattering has proven to be an advantageous method for studying triglycerides, as little sample is needed to quantify the system's hierarchical structures. Specifically, ultra-small-angle X-ray scattering (USAXS) has emerged as a fitting technique for studying CNPs, owing to its length scale range falling between 25 nm and 3.49 μm. In this study, we characterized four different 30% fat dilutions of stearic acid-based fats in triolein, with various purities and preparation protocols. Samples were characterized by combining diverse microscopy techniques (cryo-SEM, TEM, polarized light and phase contrast microscopy) with synchrotron-radiation X-ray scattering (WAXS, SAXS, and USAXS). A shape-dependent model for the interpretation of USAXS data is proposed, overcoming some of the drawbacks linked to previously utilized models. CNPs are modeled as polydisperse parallelepipeds, and the aggregates are characterized by fractal dimensionality. This model offers novel insights into CNP cross-section, as well as aggregation. In the long run, we hope that the model will increase our understanding of CNP conformation and interactions, helping us design new fat systems on the mesoscale.

Characterization of acorn oil and its application on carnauba wax-based oleogel and chocolate spread

This study aimed to characterize acorn oil (AO) and carnauba wax-based acorn oil oleogel (AOG) and the effect of AOG replacement on the textural and sensorial properties of chocolate spread. Oil yields from cold-pressing (Quercus longipes) were around 14%wt with a nice nutty smell. The main fatty acids of AO were included oleic, linoleic, and palmitic acid (44, 38, and 10%wt) respectively. The prepared AOG using 6%wt of carnauba wax (CW) showed high strength (G' > 100 mPa) and oil binding capacity ∼87 %. Based on microstructure assays platelet-like and β' polymorphic triglyceride crystalline networks were formed in AOG. The Pickering AOG/water emulsions in the volumetric ratio of from 90:10 up to 40:60 were stable due to the placement of CW-based AOG particles at the interface of water/oil as Pickering stabilizer. The high physical stability of the emulgel against phase separation is considered an important advantage for using oleogel in chocolate spread formulations instead of vegetable oils, which usually have a high percentage of oil release. The spreads prepared by replacing 50%wt AOG with butter showed acceptable textural and sensorial properties.

Development of Anthocyanin-Rich Gel Beads from Colored Rice for Encapsulation and In Vitro Gastrointestinal Digestion

Colored rice anthocyanins are water-soluble natural pigments that can be used as an active ingredient in healthy food and pharmaceutical products. However, anthocyanin utilization is limited because of its instability. This work produced anthocyanin-rich gel beads from colored rice using a modified ionotropic gelation technique for encapsulation, and their efficacy was studied in vitro in the gastrointestinal tract. In total, 15 colored rice samples of three types (whole grain rice, ground rice, and ground germinated rice) were screened to identify the highest anthocyanin content. The anthocyanin content of the whole grain rice was significantly (p < 0.05) higher than it was in the ground and ground germinated rice. The sample with the highest anthocyanin content (1062.7 µg/g) was the black glutinous rice grain from Phrae, chosen based on its anthocyanin-rich crude extract. A new formula using a modified ionotropic gelation technique was prepared for the inclusion of the extract in gel beads. The results indicated that the incorporation of oil and wax significantly increased the encapsulation efficiency of the gel beads (% EE value of 85.43%) and improved the bioavailability of the active ingredient. Moreover, after simulated digestion, the release of anthocyanin and total phenolic content occurred more than five times. Scanning electron microscopy revealed that the surface of the gel beads was smooth. Furthermore, the presence of polyphenols and polysaccharides in the gel beads was confirmed using FTIR. The oil-wax-incorporated, anthocyanin-rich gel beads could be implemented for antioxidant delivery into the gastrointestinal tract to further improve healthy food and nutraceutical products.

Waxy Oleogels for Partial Substitution of Solid Fat in Margarines

One of the research directions of oleogels is to study the possibility of their practical application in the food industry as an alternative to solid fats. In this work, the possibility of replacing solid fat in margarine (fat content 82.5%) with oleogels was evaluated. The oleogel content varied from 10 to 50% of the fat phase. The concentration of gelator for which beeswax or wax components (9:1 combination of beeswax and hydrocarbons) were used represented 3% in oleogels. The fatty acid composition of the fat components used, their textural characteristics, and their color were studied. The following physicochemical and rheological properties of margarines were determined: color values, textural and thermal characteristics, and sensory properties. The data obtained were processed using principal component analysis (PCA). Oleogels were characterized by lower textural properties compared to commercial fat (CF), but a lower content of saturated fatty acids. When using oleogels, the color characteristics of the margarines changed insignificantly. A decrease in textural and organoleptic properties was shown when using more than 30% oleogel in the composition of margarines. It was found that an increase in the proportion of oleogel leads to a decrease in the melting enthalpy of margarines. The margarines, depending on the ratio of oleogel in the fat phase, were characterized by a content of saturated fatty acids reduced by 7-35% and increased by a 18-92% level of polyunsaturated fatty acids. Thus, the application of oleogels in margarine technology makes it possible to adjust the fatty acid composition while improving the physicochemical properties.