Enhancing the Gastrointestinal Stability of Curcumin by Using Sodium Alginate-Based Nanoemulsions Containing Natural Emulsifiers

Curcumin presents interesting biological activities but low chemical stability, so it has been incorporated into different emulsion-based systems in order to increase its bioaccessibility. Many strategies are being investigated to increase the stability of these systems. Among them, the use of polysaccharides has been seen to highly improve the emulsion stability but also to modulate their digestibility and the release of the encapsulated compounds. However, the effect of these polysaccharides on nanoemulsions depends on the presence of other components. Then, this work aimed to study the effect of alginate addition at different concentrations (0–1.5%) on the gastrointestinal fate and stability of curcumin-loaded nanoemulsions formulated using soybean lecithin or whey protein as emulsifiers. Results showed that, in the absence of polysaccharides, whey protein was more effective than lecithin in preventing curcumin degradation during digestion and its use also provided greater lipid digestibility and higher curcumin bioaccessibility. The addition of alginate, especially at ≥1%, greatly prevented curcumin degradation during digestion up to 23% and improved the stability of nanoemulsions over time. However, it reduced lipid digestibility and curcumin bioaccessibility. Our results provide relevant information on the use of alginate on different emulsifier-based nanoemulsions to act as carriers of curcumin.     

Effect of oil unsaturation and wax composition on stability,properties and food applicability of oleogels

Oleogelation is emerging as one of the most exigent oil structuring technique. The main objective of this study was to formulate and characterize rice bran/sunflower wax-based oleogels using eight refined food grade oils such as sunflower oil, mustard oil, soybean oil, sesame oil, groundnut oil, rice bran oil, palm oil, and coconut oil. Stability and properties of these oleogels with respect to oil unsaturation and wax composition were explored. Sunflower wax exhibited excellent gelation ability even at 1%–1.5% (w/v) concentration compared to rice bran wax (8%–10% w/v). As the oleogelator concentration increased, peak melting temperature also increased with increase in strength of oleogels as per rheological studies. X-ray diffraction and morphological studies revealed that oleogel microstructure has major influence of wax composition only. Sunflower wax oleogels unveiled rapid crystal formation with maximum oil binding capacity of 99.46% in highly unsaturated sunflower oil with maximum polyunsaturated fatty acid content. Further, the applicability of this wax based oleogels as solid fat substitute in marketed butter products was also scrutinized. The lowest value of solid fat content (SFC) in oleogel was 0.20% at 25°C, resembling closely with the marketed butter products. With increase in oil unsaturation, oleogels displayed remarkable reduction in SFC. Depending upon prerequisite, oleogel properties can be modulated by tuning wax type and oil unsaturation. In conclusion, this wax-based oleogel can be used as solid fat substitute in food products with extensive applications in other fields too.     

Oleogels Based on Palmitic Acid and Safflower Oil: Novel Formulations for Ocular Drug Delivery of Voriconazole

The gelation of the vegetable oils using fat crystals has gained significant attention in recent years. These formulations have been explored for food and pharmaceutical applications. The alteration in the properties of palmitic acid (20–40% w/w) and safflower oil oleogels is extensively studied at microscopic and macroscopic levels. The thermal and mechanical stability of the oleogels is improved when the proportion of the palmitic acid content is increased. However, under stress, the fat crystal network junction zones of the oleogels with higher proportions of palmitic acid undergo disruption. The changes in the properties of the oleogels are due to the alteration in the molecular packing, crystallite size, and lattice strain of the fat crystal network. The alteration in the properties is governed by the changes in the extent of inter‐ and intramolecular hydrogen bonding within the components of the oleogels. The oleogels can demonstrate the ability to deliver the drug, voriconazole, across the corneal tissue. Further, the prepared oleogels are biocompatible to murine fibroblast cells and do not elicit adverse reactions when instilled within the ocular sac of rabbits. The results suggest that the oleogels can be tried as ocular delivery vehicles. Practical Applications: The delivery of drug into the internal structure of the eye is a great challenge for the ophthalmologists. Usually no more than 1% of the drug can be delivered through conventional techniques. Various researchers have proposed the use of lipid‐based ocular drug delivery systems. Some of them include solid liquid nanoparticles, emulsions, and liposomes. However, the preparation of these formulations requires a tedious process. Keeping this in mind, it is proposed to synthesize oleogel as probable ocular drug delivery system.     

Physical Properties of Beeswax,Sunflower Wax,and Candelilla Wax Mixtures and Oleogels

To be able to tailor and optimize the physical properties of oleogels for various food applications, more information is needed to understand how different gelators interact. Therefore, the objectives of this study were to evaluate the interactions between binary mixtures of beeswax (BW), candelilla wax (CLW), and sunflower wax (SFW) in pure form as well as in 5% wax oleogels made with soybean oil, in terms of their crystallization and melting properties, crystal morphology, solid fat content, and gel firmness. CLW:BW mixtures had eutectic melting properties, and oleogels from these mixtures with 40:60 to 90:10 CLW:BW were firmer compared to oleogels made with one wax. The main components in SFW and BW appeared to cocrystallize or crystallize at the same temperature, but nonlinear changes in melting point and solid fat content profile of oleogels prepared with the mixed waxes indicated that SFW dominated oleogel formation. In addition, oleogels prepared with mixtures of SFW and BW had lower firmness compared to oleogels prepared with one wax, indicating an incompatibility between the two waxes. The main wax components in SFW and CLW never cocrystallized, and low levels of CLW appeared to prevent SFW from forming a crystalline platelet network. This resulted in low firmness of oleogels made from mixtures of 90:10 to 60:40 SFW:CLW compared to oleogels prepared with one wax. However, the firmest oleogels of all mixtures were made from 10:90 SFW:CLW. Changes in gel firmness and melting properties with mixed wax oleogels were likely to be due to changes observed in the crystal size and morphology. In addition, the firmest gels were shown to result from mixtures that were predicted to have >40% hydrocarbon content, and a high hydrocarbon to wax ester ratio, but minor components such as free fatty acids and fatty alcohols may have also influenced firmness.     

Characterization and comparison of oleogels and emulgels prepared from Schizochytrium algal oil using monolaurin and MAG/DAG as gelators

Oleogels and emulgels were developed with winterized algal oil from Schizochytrium spp. rich in ω-3 fatty acids (FAs) to overcome physical limitations of using a highly unsaturated lipid source in food applications. Both gel types were developed using monolaurin or a combination of mono- and diacylglycerols (MAG/DAG) as the gelator at concentrations of 8%, 10%, or 12% (w/w) in oil or emulsion. A 30-day oxidation study was conducted using peroxide value, p-Anisidine value, and change in FA composition to measure the level of oxidation. Oleogel and emulgel samples exhibited a higher oxidative stability than bulk algal oil and oil-in-water emulsion as control groups, respectively. The 12% monolaurin oleogel outperformed others in oxidative stability, preventing oxidation of approximately 11.66% and 7.86% of EPA and DHA, respectively, compared to algal oil. Physical characteristics including thermal behavior, solid fat content (SFC), rheology, morphology, and polymorphism were studied. Results indicated that MAG/DAG oleogels and monolaurin emulgels were the most physically stable. The SFC of 12% MAG/DAG oleogel at 30°C was 10.27% whereas 12% monolaurin oleogel was only 4.51%. Both gel types developed with monolaurin and MAG/DAG could be used for different applications as they exhibited desirable qualities such as oxidative stability and improved physical characteristics.     

Effect of vegetable oil addition on bioaccessibility and biodegradation of polycyclic aromatic hydrocarbons in historically contaminated soils

BACKGROUND: Bioaccessibility is often the limiting factor for the biodegradation of polycyclic aromatic hydrocarbons (PAH) in soils. The present study explores the potential of amending canola oil, an economically and ecologically attractive soil additive, for the enhancement of bioaccessibility and, in consequence, biodegradation of PAH in historically contaminated, bioaccessibility limited soils. RESULTS: The amendment of canola oil (1% and 5%, w/w) to contaminated soils increased the bioaccessibility and the subsequent biodegradation of PAH with up to four rings. Residual concentrations of pyrene and fluoranthene in oil‐treated soils were 38–53% lower compared to the unamended tests. The continuous removal of bioaccessible PAH with a passive sampling system confirmed that oil amendment indeed increased bioaccessibility, leading to a lower non‐accessible PAH fraction. Canola oil amendment did, by contrast, not increase the bioaccessibility of high molecular weight PAH, likely due to their strong binding to soil organic carbon compounds. CONCLUSION: Canola oil can be used efficiently in low concentrations to render PAH up to four rings accessible for biodegradation in historically contaminated soils. Contaminants remaining in soil after treatment may pose a significantly lowered environmental risk, as is indicated by the lack of mobilisation by a solubilising agent such as canola oil. Copyright © 2009 Society of Chemical Industry     

Stability and Bioaccessibility of β-Carotene in Oil in Water Emulsions: Impact of Antioxidant Type and Emulsifier

The objective of this study is to explore the influence of proteins type and antioxidants on the physicochemical properties, in vitro digestion, and bioaccessibility of β-carotene laden emulsions. The combination of rutin and whey protein isolate provides optimal bioaccessibility while also stabilizing the emulsion system and effectively preventing β-carotene degradation. This is due to the amphiphilic rutin adsorbed into the interface of the emulsion stabilized by whey protein, resulting in partially replacing and further improving the physical and oxidative stability of the β-carotene emulsion. Meanwhile, the rutin emulsions remain stable and carotene content is still higher (22.38–32.07%) than others even after digestion. Hence, these emulsions show great potential to be applied for delivering β-carotene based on oil-in-water emulsions. This study provides valuable information to build up stable excipient emulsions for functional foods and nutraceuticals. Practical applications: β-carotene is being exploited for a range of biomedical applications. Concentrate on the blend of antioxidants and proteins displaying various properties in β-carotene O/W emulsions that can more likely convey β-carotene to the body and better keep up with natural movement.     

Oxidative Stability of Rice Bran Wax Oleogels and an Oleogel Cream Cheese Product

Recently, a number of publications demonstrated the successful applications of oleogels (OG) (liquid oils gelled through organogelators) in food products. Although many highlighted the health benefits of OG, potential negative impacts of thermal processing during oleogelation on nutrition and flavor quality of the OG‐based food are not fully studied. Hence, in this study, an oleogel‐cream‐cheese (OCC) product was formulated and the effects of OG processing on the oil's oxidative stability and the tocopherol content were investigated. The OG system used in the cheese product was prepared with high‐oleic soybean oil (HOSO) and rice bran wax. An ungelled cream‐cheese sample (UGCC) and two commercial cream‐cheese products were used as controls. Although high‐performance liquid chromatography data analysis showed a lower total tocopherol content in OG samples compared to HOSO, the samples’ α‐tocopherol content remained comparable. No significant differences were observed between the total tocopherol contents of OCC and UGCC cheese products, and the amount of all three‐tocopherol isomers remained constant during 14 days of storage. Although oxidation analysis showed more volatile compounds in OG samples compared to HOSO, there was only a minor difference in the volatile content between the OCC and UGCC samples. The results show minimal degradation of vegetable OG due to the thermal processing and storage that may help their potential application in dairy products.     

Effect of Storage Time on Wax–Wax–Hydrolyzate Canola Oil Oleogels

In this study, two natural waxes, beeswax (BW) and sunflower wax (SFW), are combined with their hydrolyzed variants to deliberately alter the waxes’ composition. The properties of the produced oleogels with different wax inclusion levels (4%, 8%, 12%, and 16% w/w) are investigated after defined intervals (2 days, 7 days, 3 weeks, and 3 months). To do so, the gels are monitored via penetrometry, microscopy, and calorimetry. Although the gels do not show any significant difference during storage in the micrographs, the calorimetric and firmness data reveal meaningful results. The heat of dissolution increases in every system investigated, indicating post-crystallization processes. Due to different solubilities of wax components, the critical gelling concentration is determined and the solid wax content is retrieved to further address the structure efficiency (S.E.). It is demonstrated that although the quantity of solids over time increases, the scaffolding effectiveness decreases in most cases. Only SFW, most likely due to sintering, shows an increase in S.E. over the storage time. Identified synergistic effects in BW and hydrolyzate mixtures decrease with increasing storage time. This work aims to contribute to a better understanding of the behavior of wax-based oleogels upon storage. Practical Applications: Although much is known about the gel properties of wax-based oleogels at short-term, the behavior over the storage period remains largely unresolved. However, this behavior is immensely important for a real application in fast and slow moving consumer goods. After all, products should always have the same consumer-relevant properties when stored at variable time frames. This applies to both food and pharmaceutical products. Knowledge of the behavior of wax-based oleogels in terms of a time-dependent change can help to choose a targeted product design and ensure product quality and consumer satisfaction.     

Physical Properties of Soybean Oleogels and Oil Migration Evaluation in Model Praline System

The present study examined the physical properties of soybean oleogels and commercial confectionery filling fats and evaluated the oil migration properties in model praline systems. Soybean oleogels were prepared using different oleogelators namely monoglyceride (MAG oleogels) and a mixture of sorbitan tri‐stearate (STS) with lecithin (50:50) (Lec‐STS oleogels). Both MAG oleogels and Lec‐STS oleogels demonstrated a flat solid fat content (SFC) profile with zero SFC at 40 °C. At low temperature, MAG oleogels and Lec‐STS oleogels demonstrated a non‐flowing gel‐like property due to the ability of the oleogelator to entrap liquid oil. In addition, oleogels also showed thixotropic behavior indicating the possible capability to prevent migration of filling fats to coatings and also good flow ability during pumping though manufacturing equipment. The textural property of oleogels also did not change significantly upon storage indicating good structural stability. When used as in a model praline system, oleogels demonstrated a migration delaying property.     

Increasing the firmness of wax-based oleogels using ternary mixtures of sunflower wax with beeswax:candelilla wax combinations

Oleogels were prepared with 5% wax in soybean oil using mixtures of beeswax (BW) and candelilla wax (CLW) with ratios of 10:90, 30:70, 50:50, and 60:40 BW:CLW, and the same series where 10% of the total wax was substituted with sunflower wax (SFW). The hypothesis that SFW would increase the firmness of the oleogels without affecting the melting properties was tested. Firmness of one-wax oleogels decreased from SFW > CLW > BW. Oleogels with 50:50 BW:CLW and 60:40 BLW:CLW had equal firmness to pure 5% SFW oleogels. SFW significantly increased oleogel firmness and reduced the softening that occurred between 4°C and 22°C. Increased firmness was also found with rice bran wax and behenyl-behenate (C44) addition, but not with wax esters with chain lengths ranging from 30 to 40 carbons (C30 to C40). By differential scanning calorimetry, SFW significantly decreased the melting point of oleogels with 10:90 and 30:70 BW:CLW mixtures but significantly increased the melting point of those with 50:50 and 60:40 BW:CLW mixtures. However, the solid fat content melting curves were not significantly influenced by SFW addition. These results indicate that mixed wax oleogels had greater hardness and elasticity, and that the long chain wax esters contributed by SFW helped to improve the strength of oleogels without negatively affecting their melting properties.     

Study on the Introduction of Solid Fat with a High Content of Unsaturated Fatty Acids to Gluten-Free Muffins as a Basis for Designing Food with Higher Health Value

Background: Shortenings are high in undesirable nutritionally saturated fatty acids. The aim of the study was to produce gluten-free muffins (GFM) of increased health quality and available to people intolerant to gluten, in which the shortenings were replaced with solid oleogels, consisting of 95% rapeseed oil. Methods: The dough and baked products were subjected to physical, textural, and structural analyses. Moreover, the fatty acids composition, chemical quality of fats extracted from muffins, and color of the products were determined. The dough was also observed at 600× magnification in bright field and polarized light microscopy, and microtomographic analysis of the structure of GTM was performed. Results: There was no effect of the type of lipids on physical properties, including water content in gluten-free muffins. However, the baked products differed in total porosity and brightness, as well as intensity of red and yellow colors. The use of rapeseed oil oleogels, instead of shortening in the muffin recipe, resulted in a decrease in the dietary undesirable SFA in lipid fractions (by approximately 40%), an increase in the content of MUFA (by approximately 30%), and an increase in the content of PUFA (by approximately 15%), with acceptable chemical quality. Conclusions: Research confirms the possibility of obtaining products with increased nutritional value available to consumers on a gluten-free diet.     

Oxidative stability and characterization of oleogels obtained from safflower oil-based beeswax and rice bran wax and their effect on the quality of cake samples

Safflower oil-based oleogels were produced from beeswax and rice bran wax. Oleogels demonstrated higher oxidative stability than shortening at the cooking temperature. Peroxide values in shortening, rice bran wax oleogels, and beeswax oleogels samples were found in the range of 4.8–27.76, 13.21–20.45 and 4.30–7.72 meqO₂kg⁻¹ oil. Following oleogelation, there was no significant change in fatty acid composition of safflower oil. In addition, after baking process, the changes in the major fatty acids were not determined to be significant. Solid fat content ratios (carried out at 35°C) of rice bran wax oleogels, in beeswax oleogels and in shortening samples were defined in the range of 4.10%–7.70%, 0.80%–5.00%, and 9.61%, respectively. The highest oil binding capacity was revealed in beeswax oleogels with 99.93%–99.98%. The shortest crystallization time was determined as 3 min in oleogel containing 10% rice bran wax. Cakes consisted of oleogel were acceptable in terms of texture and sensory properties compared to cake produced with shortening. Sensory results revealed that some cakes produced with oleogels were found to be more acceptable as compared with control group samples. In this respect, oleogels produced with safflower oil-based beeswax and rice bran wax could be used instead of commercial solid fat widely used in the cake industry.     

Use of organogel-based emulsions (o/w) as a tool to increase the bioaccessibility of lupeol,curcumin, and quercetin

Lupeol, curcumin, and quercetin are naturally occurring compounds present in plants, with some beneficial health effects. In the present study, organogel-based emulsions (o/w) were obtained from edible oils to increase their bioaccessibility and intestinal permeability. Particle size analysis, rheology test, optical microscopy, in vitro digestibility, and permeability of nutraceuticals by cell culture and UPLC-MS/MS were performed. Particle hydrodynamic diameters obtained in organogel-based emulsions loaded with nutraceuticals were <200 nm, polydispersity index was around 0.25–0.4, and zeta potential was about −19 to −25 mV. Droplets in emulsions presented spherical shapes and adjusted to the Herschel–Bulkley model. Interestingly, bioaccessibility and intestinal permeability of lupeol was increased compared with its crystalline form, opposite to the observed for curcumin and quercetin; therefore, organogel-based emulsions loaded with lupeol have potential for controlled oral delivery of this nutraceutical.     

Determining the structure and stability of essential oil-sunflower wax and beeswax oleogels

In this study, essential oil oleogels were produced using eucalyptus, lavender, lemon peel and tea tree oils with sunflower and beeswax. The physicochemical, thermal, textural, and structural features of the oleogels were determined. For the essential oils used, an addition level of less than 15% of beeswax (BW) was insufficient to form stable oleogels, whereas an addition level of 10% of sunflower wax (SW) was sufficient to form stable oleogels. The acid and peroxide values of the gels were higher than those of the oils. All of the oleogels exhibited peaks around 3.70 and 4.10, indicating the presence of β' polymorphic forms. The hardness and stickiness values of the oleogels were influenced by the type and level of wax addition, as well as the viscosity of the oil used. Based on the thermal analysis results, the oleogels based on beeswax exhibited lower melting properties compared to those based on sunflower wax. The thermogravimetric data indicated that the polymeric matrices formed by the waxes, which depended on the type and level of wax addition, affected the vaporization of the volatiles. In conclusion, oleogels represent a green and sustainable approach for reducing the loss of volatile or bioactive compounds from various essential oils, which are widely used in the food, cosmetics, and pharmaceutical industries.     

Properties of Oleogels Formed With High‐Stearic Soybean Oils and Sunflower Wax

In an effort to develop alternatives for harmful trans fats produced by partial hydrogenation of vegetable oils, oleogels of high‐stearic soybean (A6 and MM106) oils were prepared with sunflower wax (SW) as the oleogelator. Oleogels of high‐stearic oils did not have greater firmness when compared to regular soybean oil (SBO) at room temperature. However, the firmness of high‐stearic oil oleogels at 4 °C sharply increased due to the high content of stearic acid. High‐stearic acid SBO had more polar compounds than the regular SBO. Polar compounds in oil inversely affected the firmness of oleogels. Differential scanning calorimetry showed that wax crystals facilitated nucleation of solid fats of high‐stearic oils during cooling. Polar compounds did not affect the melting and crystallization behavior of wax. Solid fat content (SFC) showed that polar compounds in oil and wax interfered with crystallization of solid fats. Linear viscoelastic properties of 7% SW oleogels of three oils reflected well the SFC values while they did not correlate well with the firmness of oleogels. Phase‐contrast microscopy showed that the wax crystal morphology was slightly influenced by solid fats in the high‐steric SBO, A6.     

Evaluation of Beeswax,Candelilla Wax,Rice Bran Wax,and Sunflower Wax as Alternative Stabilizers for Peanut Butter

Four natural waxes were evaluated as stabilizers in peanut butter. The potential advantage of using natural waxes would be the replacement of current stabilizers such as hydrogenated or tropical oils, thereby reducing saturated fats and satisfying clean label requirements. Beeswax (BW), candelilla wax (CLW), rice bran wax (RBW), sunflower wax (SFW), and a commercial peanut butter stabilizer, hydrogenated cottonseed oil (HCO), were added to three natural peanut butter brands at levels ranging from 0.5% to 2.0% (w/w) and tested for accelerated oil release, long-term stability, firmness, and rheology. At levels ≥0.5%, all waxes improved oil-binding capacity (OBC). SFW and HCO had the highest OBC, followed by RBW, CLW, and BW. All waxes reduced the amount of oil separation after 6 months at 22 ± 2 °C. HCO followed by SFW reduced oil separation the most, but there were no significant differences between stabilizers at 1–2%. Firmness and yield stress increased with increasing stabilizer level, with SFW increasing firmness the most, followed by HCO, RBW, and CLW, while BW had the lowest effect. The results indicate that the waxes may be feasible replacements for hydrogenated oils as peanut butter stabilizers, but levels would need to be optimized depending on the product characteristics and wax type.     

Utilization of Beeswax Oleogel-Shortening Mixtures in Gluten-Free Bakery Products

Formulating gluten-free bakery products with acceptable physical properties generally requires a high amount of fat. As the fat used in these products is often high in saturated fatty acids, the objective of this study was to evaluate beeswax (BW) containing oleogels for partial replacement of the shortening in gluten-free aerated products. Oleogels prepared with BW were cocrystallized with a commercial cake shortening in the laboratory scale crystallization unit. Then, the resulting blends were evaluated in the gluten-free cake formulations. When the BW oleogel was used alone, the overrun values of the batter samples decreased, indicating reduced air-holding ability. Product porosity and specific volume of the samples were also diminished with complete replacement of the shortening with BW oleogel. Nevertheless, 45%, 30%, and 15% replacement of the shortening with BW oleogel resulted in batter and baked product properties comparable to those of the control products. Rheological and textural measurements, microscopy, and bubble size distribution suggested that gradual replacement of shortening with oleogels may be an alternative method for a partial reduction of saturated fat without altering the physical properties of gluten-free aerated products.     

Muffins made with monoglyceride oleogels: Impact of fat replacement on sensory properties and fatty acid profile

Most shortenings used in baked products are solid fats high in saturated fatty acids that may also contain trans fatty acids, which are nutritionally unhealthy. Successful solid fat replacement requires maintaining not only the physicochemical properties, but also the sensory quality of the products. In this study, the sensory properties and lipid profile of muffins formulated with a previously optimized monoglyceride oleogel were compared with those of muffins made with a commercial margarine (Control). Untrained consumers (n = 130) evaluated the effect of the fat replacement on several sensory attributes using a 5-point hedonic scale. In comparison with the Control, the oleogel-based muffin (M_o) scored similarly for flavor and sponginess, but rated significantly higher for appearance and color. Based on overall quality score, consumers liked M_o more than the Control. The reformulated muffins had a significantly improved lipid profile, with a 68% reduction in saturated fats and an almost 4-fold increase in monounsaturated fats. This study supports the use of monoglyceride oleogels as full-fat substitutes to develop healthier bakery products, maintaining or improving consumer acceptance. It is expected that the promising results presented here will help the food industry to accelerate the transition from conventional solid fats to oleogels.