Novel structuring strategies for unsaturated fats – Meeting the zero-trans, zero-saturated fat challenge: A review

Consumer Acceptance Studies of Margarine to Guide Product Development in the Food Industry

Margarine exhibits significant variations in composition, allowing it to cater to diverse consumer segments. This study aimed to characterize the physical and sensory attributes of margarine samples available in the Brazilian market. Twelve commercial samples from six different brands, encompassing 30% to 80% of lipid contents, were subjected to instrumental texture analysis and affective assessment. A total of 112 consumers participated in acceptance tests and Check-All-That-Apply (CATA) evaluations, while another group of 62 subjects performed Projective Mapping. Samples with lipid percentages exceeding 70% achieved the highest average acceptance scores for taste and overall impression. The brand with the lowest lipid content (30%) exhibited a stronger association with negative attributes, including rancid flavor and aroma, bitterness, and metallic flavor, resulting in lower average scores for aroma, flavor, texture, and overall impression. However, these scores were not statistically different from samples with 50% and 60% lipid content. Reducing lipid levels in fat-based products such as margarine poses a challenge to food manufacturers, as consumers generally perceive higher lipid percentages as indicative of superior flavor quality.

Mixed cyclo di-amino acids structured edible oils: a potential hardstock fat mimic

Pure cyclic diamino acids (CdAA) gel differently than combinations of CdAAs, altering the gelation behavior to highly-branched colloidal protein crystal networks reminiscent of traditional fat crystal networks in canola oil, making it an exciting structuring agent for unsaturated oils.

Palmitoylethanolamide gels edible oils

Palmitoylethanolamide (PEA) is an endogenous compound with no adverse effect for oral intakes of a gram per day. We show that PEA gels edible oils at concentrations as low as 0.5 wt%. The elastic moduli values of the formed gels are 1400 Pa at 1 wt% and 9000 Pa at 2 wt%. The study of the gels by cryo-SEM, optical microscopy and WAXS show that PEA forms lamellar solid aggregates with widths of several tens of micrometers. Upon heating, the sample shows two transitions. The first one is the gel-to-sol transition, observed by rheology and defined by the switch from a solid to a liquid behavior. During this transition, the solid particles remain but do no longer form a network. The second transition, observed at higher temperature by DSC corresponds to the melting of the solid particles.

Physical and Chemical Characterisation of Conventional and Nano/Emulsions: Influence of Vegetable Oils from Different Origins

The processes of oil production play an important role in defining the final physical and chemical properties of vegetable oils, which have an influence on the formation and characteristics of emulsions. The objective of this work was to investigate the correlations between oils’ physical and chemical properties with the stability of conventional emulsions (d > 200 nm) and nanoemulsions (d < 200 nm). Five vegetable oils obtained from different production processes and with high proportion of unsaturated fatty acids were studied. Extra virgin olive oil (EVOO), cold-pressed rapeseed oil (CPRO), refined olive oil (OO), refined rapeseed oil (RO) and refined sunflower oil (SO) were used in this study. The results showed that the physicochemical stability of emulsion was affected by fatty acid composition, the presence of antioxidants, free fatty acids and droplet size. There was a significant positive correlation (p < 0.05) between the fraction of unsaturated fatty acids and emulsion oxidative stability, where SO, OO and EVOO showed a significantly higher lipid oxidative stability compared to RO and CPRO emulsions. Nanoemulsions with a smaller droplet size showed better physical stability than conventional emulsions. However, there was not a significant correlation between the oxidative stability of emulsions, droplet size and antioxidant capacity of oils.

Effect of ultrasound on the structural characteristics and oxidative stability of walnut oil oleogel coated with soy protein isolate-phosphatidylserine

In this study, the three-dimensional network system formed by rice bran wax (RBW) was used as the internal structure, and the external structure formed by soybean protein isolate (SPI) and phosphatidylserine (PS) was added on the basis of the internal structure to prepare walnut oil oleogel (SPI-PS-WOG). Ultrasonic treatment was applied to the mixed solution to make SPI-PS-WOG, on the basis, the effects of ultrasonic treatment on SPI-PS-WOG were investigated. The results showed that both β and β' crystalline forms were present in all SPI-PS-WOG samples. When the ultrasonic power was 450 W, the first weight loss peak in the thermogravimetric (TGA) curve appeared at 326 °C, which was shifted to the right compared to the peak that occurred when the ultrasonic power was 0 W, indicating that the thermal stability of the SPI-PS-WOG was improved by the ultrasonic treatment. Moreover, when the ultrasonic power was 450 W, the oil holding capacity (OHC) reached 95.3 %, which was the best compared with other groups. Both confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) showed that the ultrasonic treatment of appropriate power succeeded in making the SPI-PS-WOG samples more evenly dispersed in the internal structure and denser in the external structure. In terms of oxidative stability, it was found that the peroxide value of SPI-PS-WOG remained at 9.8 mmol/kg oil for 50 days under 450 W ultrasonic power treatment, which was significantly improved compared with liquid walnut oil (WO). These results provide a new idea for the preparation of oleogels, and also lay a theoretical foundation for the application of ultrasonic treatment in oleogels.

Ultrasound-assisted gelation of β-carotene enriched oleogels based on candelilla wax-nut oils: Physical properties and in-vitro digestion analysis

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Candelilla wax mix with peanut, pine nut and walnut oils can form oleogels.

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Ultrasound increased G’, G’’, firmness and oil-binding capacity of oleogels.

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Ultrasound treatment improved the protection of β-carotene in oleogels.

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Ultrasound reduced the amount of β-carotene released during intestinal digestion.

This study investigated the effects of high-intensity ultrasound (HIU, 95 W, 10 s) on the physical properties, stability and in vitro digestion of β-carotene enriched oleogels. Candelilla wax (3 wt%) and nut oils (peanut, pine nut and walnut oil) with or without β-carotene were used to form oleogels. HIU improved the storage modules (G’) of peanut, pine nut and walnut oleogels without β-carotene from 11048.43 ± 728.85 Pa, 38111.67 ± 11663.98 Pa and 21921.13 ± 1011.55 Pa to 13502.40 ± 646.54 Pa, 75322.47 ± 9715.25 Pa and 48480.97 ± 4109.64 Pa, respectively. Moreover, HIU reduced oil loss of peanut, pine nut and walnut oleogels without β-carotene from 23.98 ± 2.58%, 17.14 ± 0.69% and 24.66 ± 1.57% to 17.60 ± 1.10%, 13.84 ± 0.74% and 18.72 ± 3.47%, respectively. X-ray diffraction patterns showed that HIU did not change the form of the crystal (β-polymorphic and β’-polymorphic) but increased the crystal intensity. Polarized light microscope images indicated that all oleogels showed more visible crystals after HIU. After 120 d of storage, HIU decreased the degradation of β-carotene for peanut oil and walnut oil samples (the contents of β-carotene in peanut and walnut oleogels without HIU after 120 d of storage were 897 ± 2 μg/g and 780 ± 1 μg/g, respectively, and those of sonicated samples were 1070 ± 4 μg/g and 932 ± 1 μg/g, respectively). Furthermore, HIU reduced the release of β-carotene in intestinal digestion. In conclusion, HIU could improve the functional properties of wax-nut oils oleogels and their β-carotene enriched oleogels.

Margarines: Historical approach, technological aspects, nutritional profile, and global trends

Margarines are an expanding market worldwide due to large-scale commercial, lower cost, growth of bakery and confectionery markets, and seasonal independence. The fatty acid composition, solid fat content, consistency, and melting point of the fats used in margarine determine their functional properties. Due to its proven association with increased risk of cardiovascular diseases, the recommendations of the World Health Organization and the enactment of laws in several countries to eliminate industrially produced trans fatty acids (TFA) have resulted in the prohibition or progressive reduction in the use of partially hydrogenated fat. However, issues related to high levels of TFA and saturated fatty acids still constitute a challenge in the formulation of this product category. Current trends on margarine production addition of phytosterols, non-lipid components, organogels, and new interesterified fat bases are reviewed. This review aims to present a historical view and the technological evolution of margarines, including their production processes, formulations, and physical and nutritional characteristics, as well as legislation, and main trends.

Canola protein thermal denaturation improved emulsion-templated oleogelation and its cake-baking application

The stability and viscoelasticity of an oil-in-water emulsion formed with canola proteins could be significantly improved by heat-induced protein thermal denaturation followed by aggregation at the oil droplet surface. This phenomenon was used to develop emulsion-templated oleogels with improved rheology and used in cake baking. Canola oil (50 wt%)-in-water emulsions stabilized by 1 and 4 wt% canola protein isolates (CPI), prepared by high-pressure homogenization, were dried at 60 °C in a vacuum oven followed by shearing to create the oleogels. Before drying, the emulsions were heated (90 °C for 30 min) to induce protein denaturation. The oleogel from 4 wt% CPI heated emulsions (HE) exhibited the lowest oil loss, highest gel strength, firmness and stickiness compared to all other oleogels. Cake batter prepared with shortening showed the lowest specific gravity, highest viscosity and storage modulus compared to CPI oleogels. Confocal micrographs of shortening cake batters showed smaller air bubbles entrapped in the continuous fat phase. In comparison, the oleogel cake batters showed dispersion of larger air bubbles, oil droplets, and protein aggregates. The oleogel cake showed a darker colour compared to the shortening cake due to the dark colour of CPI. Interestingly, oleogel cakes showed lower hardness, higher cohesiveness and springiness than the shortening cake, which was attributed to the higher cake volume of the former due to the formation of larger air channels stabilized by canola proteins. In conclusion, CPI stabilized emulsion-templated oleogels could be used as a potential shortening replacer in cake and other baking applications.

The stability and viscoelasticity of an oil-in-water emulsion formed with canola proteins could be significantly improved by heat-induced protein thermal denaturation followed by aggregation at the oil droplet surface.

Oleogels-Their Applicability and Methods of Characterization

Oleogels or, more precisely, non-triglyceride structured lipid phases have been researched excessively in the last decade. Yet, no comprehensive knowledge base has emerged, allowing technology elevation from the laboratory bench into the industrial food application. That is partly due to insufficient characterization of the structuring systems studied. Examining a single composition decided upon by arbitrary methods does not stimulate progress in the research and technology area. A framework that gives much better guidance to product applications can easily be derived. For example, the incremental structure contribution concept is advocated as a parameter to compare the potency of structuring systems. These can straightforwardly be determined by combining solubility data and structural measurements in the recommended manner. The current method to determine the oil-binding capacity suffers from reproducibility and relevance. A newly developed method is suggested to overcome these shortcomings. The recommended new characterization of oleogels should contribute to a more comprehensive knowledge base necessary for product innovations.

Enzymatic glycerolysis converts vegetable oils into structural fats with the potential to replace palm oil in food products

Current trans fat replacement strategies provide food products with acceptable textural and sensory properties on a large scale, and at a reasonable price, but carry health and environmental burdens. Palm oil is used extensively because of its high solidity and functionality; however, increased production has led to deforestation throughout the world's tropical regions. To reduce dependence on palm oil it is necessary to find a means of structuring a variety of readily available vegetable oils. Using cottonseed and peanut oils, among others, we show that enzymatic glycerolysis can structure liquid oils into solid fats through monoacylglycerol and diacylglycerol production from their native triacylglycerols without the addition of saturated or hydrogenated fat, thus not altering fatty acid composition. Solid fat contents of cottonseed and peanut oils were increased from 8% to 29% and 9% to 30% at 5 °C, respectively, and 21% and 10% at 20 °C, respectively. Additionally, oil-binding capacity was enhanced significantly. These novel oils were used to produce margarine and peanut butter with similar textural properties to commercial products and, importantly, represent a healthy and sustainable means to replace hydrogenated or saturated fats.

Oleogels in Food: A Review of Current and Potential Applications

Legislative limitations of the use of trans and saturated fatty acids, the rising concerns among consumers about the negative effects of some fats on human health, and environmental and health considerations regarding the increased use of palm fat in food and biodiesel production drove to innovations in reformulating fat-containing food products. Oleogelation is one of the most in-trend methods for reducing or replacing the unhealthy and controversial fats in food products. Different edible oleogels are being formulated by various techniques and used in spreads, bakeries, confectioneries, and dairy and meat products. This review exclusively focuses on up-to-date applications of oleogels in food and mechanisms of gelation, and discusses the properties of new products. Research has produced acceptable reformulated food products with similar technological and rheological properties as the reference products or even products with improved techno-functionality; however, there is still a high need to improve oleogelation methods, as well as the technological process of oleogel-based foods products. Despite other strategies that aim to reduce or replace the occurrence of trans and saturated fats in food, oleogelation presents a great potential for industrial application in the future due to nutritional and environmental considerations.

Physicochemical and rheological properties of soybean organogels: Interactions between different structuring agents

High consumption of trans and saturated fats has been related to the development of cardiovascular diseases, justifying the application of organogels as possible substitutes for industrial fats. The aim of this study was to evaluate the physicochemical and rheological characteristics of soybean organogels that were prepared with 6% (w:w) of structuring components by a simplex centroid design, individually added, in binary and ternary associations with candelilla wax (CW), sorbitan monostearate (SMS) and fully hydrogenated palm oil (HPO). The formulated organogels were evaluated for hardness, solid content, and rheological behavior. The organogels containing a high proportion of HPO had higher solid content: 8.1% with the addition of isolated HPO and a solid content of 6.9% with the addition of HPO + CW. However, isolated use of HPO resulted in lower compression/extrusion strength (0.85 N) than that obtained with isolated CW (10.45 N). All organogels exhibited Hershel-Bulkley rheological behavior, except organogel 2 (containing only SMS), which showed pseudoplastic behavior. Thus, the structuring agents used to form the organogels are capable of changing the physical behavior of unsaturated lipids depending on whether a combination of CW + HPO was added, a ternary interaction with a higher proportion of CW, and the use of isolated CW as a structuring agent, resulting in organogels of greater stability and hardness.

Physical Properties of Monoglycerides Oleogels Modified by Concentration, Cooling Rate, and High-Intensity Ultrasound

The aim of this study was to investigate the effects of monoglycerides (MG) concentration (3, 4.5, and 6 wt%), cooling rate (0.1 and 10 °C/min), and high-intensity ultrasound (HIU) application on physical properties of oleogels from MG and high oleic sunflower oil. Microstructure, melting profile, elasticity (G'), and solid fat content (SFC) were measured immediately after preparation of samples (t = 0) and after 24 hr of storage at 25 °C. Samples' textural properties (hardness, adhesiveness, and cohesiveness) and oil binding capacity (OBC) were evaluated after 24 hr at 25 °C. In general, samples became less elastic over time. Slow cooling rate resulted in lower G' after 24 hr compared to the ones obtained using 10 °C/min. Network OBC was improved by increasing MG concentration and cooling rate, and by applying HIU. After storage, oleogel melting enthalpy increased with MG concentration. In general, this behavior was not correlated with an increase in SFC. An improvement in the network structure was generally reached with the increase in cooling rate, according to texture and rheology results, for both sonicated and nonsonicated conditions. At the highest MG concentration, HIU application was more efficient at increasing OBC and hardness of the network at 0.1 °C/min. Microscopy images showed that the oleogels microstructure was changed as a consequence of HIU application and cooling rate, evidencing smaller crystals both in sonicated and faster cooled samples. Obtained results demonstrate that cooling rate, MG concentration, and HIU can be used satisfactorily to tailor physical properties of MG oleogels. PRACTICAL APPLICATION: Oleogels have been studied in the last years as semisolid fat replacers in food products. Cooling rate is an important processing parameter in the oleogel preparation because it affects their final physical properties, while high-intensity ultrasound (HIU) is a relatively novel technique to tailor lipid properties. This study is focused on the application of a slow/fast cooling rate in combination with/without HIU treatment at different monoglycerides and high oleic sunflower oil mixtures as a successful strategy to obtain oleogels with different physical properties and with potential applications in the food industry, such as fat substitutes in bakery.

Effects of Lipid Solid Mass Fraction and Non-Lipid Solids on Crystallization Behaviors of Model Fats under High Pressure

Different fractions of fully hydrogenated soybean oil (FHSBO) in soybean oil (10–30% w/w) and the addition of 1% salt (sodium chloride) were used to investigate the effect of high-pressure treatments (HP) on the crystallization behaviors and physical properties of the binary mixtures. Sample microstructure, solid fat content (SFC), thermal and rheological properties were analyzed and compared against a control sample (crystallized under atmospheric condition). The crystallization temperature (T_s) of all model fats under isobaric conditions increased quadratically with pressure until reaching a pressure threshold. As a result of this change, the sample induction time of crystallization (t_c) shifted from a range of 2.74–0.82 min to 0.72–0.43 min when sample crystallized above the pressure threshold under adiabatic conditions. At the high solid mass fraction, the addition of salt reduced the pressure threshold to induce crystallization during adiabatic compression. An increase in pressure significantly reduced mean cluster diameter in relation to the reduction of t_c regardless of the solid mass fraction. In contrast, the sample macrostructural properties (SFC, storage modulus) were influenced more significantly by solid mass fractions rather than pressure levels. The creation of lipid gel was observed in the HP samples at 10% FHSBO. The changes in crystallization behaviors indicated that high-pressure treatments were more likely to influence crystallization mechanisms at low solid mass fraction.

Edible oleogels: an opportunity for fat replacement in foods

The scientific and industrial communities have been giving great attention to the development of new bio-based materials with potential use in innovative technological applications. Among these materials are the structures with gel-like behavior that can be used in the cosmetic, pharmaceutical and food industries, aiming at controlling the physical properties of the final products. In the past ten years, words like oleogels and organogels have been increasingly used, the existing number of manuscripts and patents being proof of this tendency. In the food industry, oleogels can be used to control phase separation, and decrease the mobility and migration of the oil phase, providing solid-like properties without using high levels of saturated fatty acids as well as to be a carrier of bioactive compounds. In most cases, their main features are related to the reorganization process of gelators after an increase of the temperature, above the melting or glass transition temperature of the materials, known as the direct method, but it is also possible to develop oleogels by indirect methods, such as emulsification and the solvent exchange technique. In the direct methods, the reorganization is able to physically entrap oil leading to different physicochemical properties, the rheological behavior and texture properties being the frequently most studied ones. This review overviews the use of food grade and bio-based structurants to produce edible oleogels, aiming at fat replacement and structure-tailoring. Gelation mechanisms and oil phases used during oleogel production are discussed, as well as the current food applications and future trends for this kind of structure.

Beyond Covalent Crosslinks: Applications of Supramolecular Gels

Traditionally, gels have been defined by their covalently cross-linked polymer networks. Supramolecular gels challenge this framework by relying on non-covalent interactions for self-organization into hierarchical structures. This class of materials offers a variety of novel and exciting potential applications. This review draws together recent advances in supramolecular gels with an emphasis on their proposed uses as optoelectronic, energy, biomedical, and biological materials. Additional special topics reviewed include environmental remediation, participation in synthesis procedures, and other industrial uses. The examples presented here demonstrate unique benefits of supramolecular gels, including tunability, processability, and self-healing capability, enabling a new approach to solve engineering challenges.

Potential application of lipid organogels for food industry

Controversial issues regarding the role of trans fatty acids in food have led to progressive changes in the legislation of several countries to include more information for consumers. In response, the industries decided to gradually replace trans fat in various products with the development of fatty bases of equivalent functionality and economic viability to partially hydrogenated fats, causing, however, a substantial increase in the content of saturated fatty acids in foods. Today, the lipid science aims to define alternatives to a problem that is widely discussed by health organizations worldwide: limit the saturated fat content in food available to the population. In this context, organogels have been indicated as a viable alternative to obtain semi-solid fats with reduced content of saturated fatty acids and compatible properties for food application. The objective of this review was to present the studies that address the lipid organogels as an alternative for food application.

Low sat-structured fats enriched in α-linolenic acid: physicochemical properties and crystallization characteristics

This work sought to obtain and evaluate zero trans-fat reduced in saturated fatty acids, with higher content of unsaturated fatty acids. Palm oil (PO) was used as the reference of zero trans lipid base. Different amounts of linseed oil (LO) were added to PO, obtaining the following blends: 100:0; 80:20; 60:40; 40:60; 20:80 and 0:100 of PO:LO (w/w%), respectively. These blends were added to fully hydrogenated soybean oil (FHSO) as the crystallization modifying agent, and to sorbitan monostearate (SMS) as the structuring element, both at a proportion of 3% to build the structured fractions. The control and the structured blends were evaluated for fatty acid composition, solid fat content, consistency, crystallization kinetics, thermal behavior, microstructure and polymorphism. With the addition of LO to the PO, an increase of up to 80% was observed in the content of alpha-linolenic acid and a reduction of saturated fatty acids to 47% in the blends. FHSO and SMS offered thermal resistance to the blends, with relevant changes in the crystallization kinetics and microstructure, affecting macroscopic characteristics with the increase in consistence. It was possible to obtain a lipid formulation with features of plasticity and enhanced nutritional quality, compatible with several food applications.

Advances in edible oleogel technologies - A decade in review

Trans and saturated fat replacers/substitutes have been a tremendously active area of research for the food industry. Unlike polymers used for hydrogels, oleogels utilize small, amphiphilic molecules that self-assemble via highly specific, non-covalent interactions entrapping liquid oil via capillary forces. Edible applications of oleogels have replaced the need for trans unsaturated and saturated fatty acids to structure processed foods. These innovations mitigate the use of hardstock fats that are associated with deleterious health risks and negative consumer perception. Over the past decade, oleogels have made significant strides towards emulating desired sensory traits while maintaining healthy nutritional profile of the oil. Due to the rapid advancements in the past decade, the most promising technologies will be reviewed.

Controlling Agglomeration of Protein Aggregates for Structure Formation in Liquid Oil: A Sticky Business

Proteins are known to be effective building blocks when it comes to structure formation in aqueous environments. Recently, we have shown that submicron colloidal protein particles can also be used to provide structure to liquid oil and form so-called oleogels ( de Vries , A. J. Colloid Interface Sci. 2017 , 486 , 75 - 83 ) . To prevent particle agglomeration, a solvent exchange procedure was used to transfer the aggregates from water to the oil phase. The aim of the current paper was to elucidate on the enhanced stability against agglomeration of heat-set whey protein isolate (WPI) aggregates to develop an alternative for the solvent exchange procedure. Protein aggregates were transferred from water to several solvents differing in polarity to investigate the effect on agglomeration and changes in protein composition. We show that after drying protein aggregates by evaporation from solvents with a low polarity (e.g., hexane), the protein powder shows good dispersibility in liquid oil compared to powders dried from solvents with a high polarity. This difference in dispersibility could not be related to changes in protein composition or conformation but was instead related to the reduction of attractive capillary forces between the protein aggregates during drying. Following another route, agglomeration was also prevented by applying high freezing rates prior to freeze-drying. The rheological properties of the oleogels prepared with such freeze-dried protein aggregates were shown to be similar to that of oleogels prepared using a solvent exchange procedure. This Research Article provides valuable insights in how to tune the drying process to control protein agglomeration to allow for subsequent structure formation of proteins in liquid oil.