Recent developments of oleogel utilizations in bakery products

Effect of fat replacement in high internal phase emulsions constructed by high temperature saccharification of grafted proteins on gel properties and flavor profiles of sausages

In order to mitigate the risk of cardiovascular diseases associated with excessive saturated fatty acid intake, utilizing high internal phase emulsions (HIPEs) as a substitute for animal fat in producing high-quality fat-substituted meat products is an ideal approach. This study involves the preparation of glycosylation products of egg white protein (EWP) through saccharification at high temperatures in the presence of fructooligosaccharides (FO). The resulting glycation products of EWP were employed to create colloidal particles, forming HIPEs, which were further utilized to induce the formation of HIPEs gels (HIPEs-Gs). The study investigated the effects of substituting different ratios (25%, 50%, 75%, and 100%) of animal fat with HIPEs and HIPEs-Gs on the gel properties and flavor characteristics of sausages. Results showed that, compared to the control group, substituting fat with HIPEs significantly improved the gel properties, cooking yield, and G' of sausages, while excessive HIPEs-Gs substitution yielded negative effects. Low-field nuclear magnetic resonance results also demonstrated that adding HIPEs improved water and oil distribution in the sausage batter, enhancing protein's binding capacity with water. Scanning electron microscope revealed that HIPEs substitution led to a denser gel network with smaller pores, effectively "locking in" more water. Analysis of volatile compounds indicated accelerated release of aromatic compounds, alkanes, sulfides, and lipids when fat was substituted with HIPEs and HIPEs-Gs. Electronic tongue analysis suggested that HIPEs-Gs substitution reduced response values for umami and saltiness. In conclusion, compared to HIPEs-Gs, using HIPEs as a fat substitute improves the quality of sausages.

A review of oleogels applications in dairy foods

The characteristics of dairy products, such as texture, color, flavor, and nutritional profile, are significantly influenced by the presence of milk fat. However, saturated fatty acids account for 65% of total milk fat. With increased health awareness and regulatory recommendations, consumer preferences have evolved toward low/no saturated fat food products. Reducing the saturated fat content of dairy products to meet market demands is an urgent yet challenging task, as it may compromise product quality and increase production costs. In this regard, oleogels have emerged as a viable milk fat replacement in dairy foods. This review focuses on recent advances in oleogel systems and explores their potential for incorporation into dairy products as a milk fat substitute. Overall, it can be concluded that oleogel can be a potential alternative to replace milk fat fully or partially in the product matrix to improve nutritional profile by mimicking similar rheological and textural product characteristics as milk fat. Furthermore, the impact of consuming oleogel-based dairy foods on digestibility and gut health is also discussed. A thorough comprehension of the application of oleogels in dairy products will provide an opportunity for the dairy sector to develop applications that will appeal to the changing consumer needs.

Oleogel Systems for Chocolate Production: A Systematic Review

In response to the growing demand for healthier food options, this review explores advances in oleogel systems as an innovative solution to reduce saturated fats in chocolates. Although appreciated for its flavor and texture, chocolate is high in calories, mainly due to cocoa butter (CB), which is rich in saturated fats. Oleogels, three-dimensional structures formed by structuring agents in edible oils, stand out in terms of mimicking saturated fats' physical and sensory properties without compromising the quality of chocolate. This study reviews how oleogels could improve chocolate's stability and sensory quality, exploring the potential of pectin-rich agro-industrial by-products as sustainable alternatives. It also explores the need for physicochemical evaluations of both oleogel and oleogel-based chocolate.

Destabilization of a model O/W/O double emulsion: From bulk to interface

Oil-in-water-in-oil (O/W/O) double emulsions are considered an advanced oil-structuring technology that can accomplish multi-functions to improve food quality and nutrition. However, this special structure is thermodynamically unstable. This study formulated a model O/W/O double emulsion with standard surfactants, Tween 80 (4 %) and polyglycerol polyricinoleate (PGPR, 5 %), using a traditional two-step method with different homogenization parameters. Cryo-SEM and GC-FID results show that O/W/O emulsions were successfully formulated, and the release rate (RR) of medium-chain triglycerides (MCT) oil from the inner oil to the outer oil phase increased significantly with 2nd homogenization speed increasing, respectively. Interestingly, the RR of all samples reached about 75 % after 2 months of storage, suggesting that O/W/O emulsions were highly unstable. To explain the observed instability, dynamic interfacial tension and interfacial rheology were performed using a drop shape tensiometer. Results demonstrated that unadsorbed Tween 80 in the intermediate aqueous phase was a key factor in markedly decreasing the interfacial properties of the outer PGPR-assembled film by affecting the interfacial rearrangement. Additionally, it was found that the MCT release showed a positive correlation with the Tween 80 concentration, demonstrating that the formed Tween 80 micelles could transport oil molecules to strengthen the emulsion instability. Taken together, this study reveals the destabilization mechanism of model O/W/O surfactants-stabilized emulsions from bulk to interface, providing highly relevant insights for the design of stable O/W/O double emulsions.

Shellac-based delivery systems for food bioactive compounds

Shellac is a natural resin featuring some attractive properties such as amphiphilicity, pH responsiveness, biocompatibility, and biodegradability. There has been increasing interest in employing shellac for controlled delivery of food bioactive compounds. This review outlines the recent advances in different types of shellac-based delivery systems, including nanoparticles, zein-shellac particles, hydrogels, nanofibers, and nanomicelles. The preparation method, formation mechanism, structure, and delivery performance are investigated. These systems could improve the stability and shelf-life of bioactive compounds, allow for targeted release at the small intestine or colon site, and increase bioavailability. The deficiencies and challenges of each of the systems are also discussed. The promising results in this review could guide future trends in more efficient shellac-based delivery platforms for functional food applications.

A novel edible solid fat substitute: Preparation of biphasic stabilized bigels based on glyceryl monolaurate and gellan gum

Solid fats contribute to a delicate and pleasant flavor for food, but its excessive intake increases the risk of cardiovascular disease. Bigel is considered a promising solid fat substitute as it significantly reduces fat content while meeting consumer demands for food flavor and a balanced diet. In this study, bigels were prepared by mixing glyceryl monolaurate-based oleogel (10 wt%) and gellan gum-based hydrogel (0.8 wt%) at ratios of 1:3, 1:1, and 3:1. The microscopic results indicated that the oleogel/hydrogel ratios influenced the structure of bigels, forming oil-in-water, bi-continuous, and water-in-oil bigels with the increase of oleogel proportion, respectively. All bigels presented a semi-solid structure dominated by elasticity, and their hardness, gumminess, chewiness, and cohesiveness increased with the enhancement of hydrogel proportion. Among them, the bigels (S25:L75 and S25:H75) prepared with an oleogel/hydrogel ratio of 1:3 showed excellent freeze-thaw stability, maintaining an oil holding capacity of >95 % after three freeze-thaw cycles. Meanwhile, they also presented good oxidative stabilities, where the peroxide values and malondialdehyde contents were below 0.07 g/100 g and 1.5 mg MDA/kg at 12 d, respectively. Therefore, S25:L75 and S25:H75 are expected to be green, low-cost, healthy, and sustainable alternatives to solid fats.

Characterization of Beeswax and Rice Bran Wax Oleogels Based on Different Types of Vegetable Oils and Their Impact on Wheat Flour Dough Technological Behavior during Bun Making

Five varieties of vegetable oil underwent oleogelation with two types of wax as follows: beeswax (BW) and rice bran wax (RW). The oleogels were analyzed for their physicochemical, thermal, and textural characteristics. The oleogels were used in the bun dough recipe at a percentage level of 5%, and the textural and rheological properties of the oleogel doughs were analyzed using dynamic and empirical rheology devices such as the Haake rheometer, the Rheofermentometer, and Mixolab. The thermal properties of beeswax oleogels showed a melting peak at a lower temperature for all the oils used compared with that of the oleogels containing rice bran wax. Texturally, for both waxes, as the percentage of wax increased, the firmness of the oleogels increased proportionally, which indicates better technological characteristics for the food industry. The effect of the addition of oleogels on the viscoelastic properties of the dough was measured as a function of temperature. All dough samples showed higher values for G' (storage modulus) than those of G″ (loss modulus) in the temperature range of 20-90 °C, suggesting a solid, elastic-like behavior of all dough samples with the addition of oleogels. The influence of the beeswax and rice bran oleogels based on different types of vegetable oils on the thermo-mechanical properties of wheat flour dough indicated that the addition of oleogels in dough recipes generally led to higher dough stability and lower values for the dough development time and those related to the dough's starch characteristics. Therefore, the addition of oleogels in dough recipes inhibits the starch gelatinization process and increases the shelf life of bakery products.

New Insight into Food-Grade Emulsions: Candelilla Wax-Based Oleogels as an Internal Phase of Novel Vegan Creams

Cream-type emulsions containing candelilla wax-based oleogels (EC) were analyzed for their physicochemical properties compared to palm oil-based creams (EP). The microstructure, rheological behavior, stability, and color of the creams were determined by means of non-invasive and invasive techniques. All the formulations exhibited similar color parameters in CIEL*a*b* space, unimodal-like size distribution of lipid particles, and shear-thinning properties. Oleogel-based formulations were characterized by higher viscosity (consistency index: 172-305 mPa·s, macroscopic viscosity index: 2.19-3.08 × 10-5 nm-2) and elasticity (elasticity index: 1.09-1.45 × 10-3 nm-2), as well as greater resistance to centrifugal force compared to EP. Creams with 3, 4, or 5% wax (EC3-5) showed the lowest polydispersity indexes (PDI: 0.80-0.85) 24 h after production and the lowest instability indexes after environmental temperature changes (heating at 90 °C, or freeze-thaw cycle). EC5 had particularly high microstructural stability. In turn, candelilla wax content ≥ 6% w/w accelerated the destabilization processes of the cream-type emulsions due to disintegration of the interfacial layer by larger lipid crystals. It was found that candelilla wax-based lipids had great potential for use as palm oil substitutes in the development of novel vegan cream analogues.

Characterization of mixed-component oleogels: Beeswax and glycerol monostearate interactions towards Tenebrio Molitor larvae oil

Edible insects are attracting attention as an alternative food due to their excellent production efficiency, lower carbon consumption, and containing high protein. Tenebrio Molitor larvae (TM), one of the approved edible insects worldwide, contain more than 30 % fat content consisting of 70 % unsaturated fatty acids, and particularly high phospholipids. Most of the research has focused on the utilization of proteins, and there are few studies using oils from TM. Therefore, in this study, to expand the utilization of TM oil in food applications, the oleogel was prepared with TM oil fortified by the incorporation of beeswax (BSW) and glycerol monostearate (GMS), and their structure, rheological and thermal properties were evaluated. The interaction between BSW and GMS contributed to the strength of the oleogel structure. The addition of GMS or the increase of the gelator concentrations resulted in increasing the melting point, which is consistent with the observed increase in viscoelasticity. As the temperature increased, the solid fat content decreased. The result of FT-IR suggests that TM oil is physically solidified without changing chemical composition through oleogelation. This study suggests a new processing direction for edible insects by confirming the rheological, thermal, and physicochemical characteristics of TM oil-based oleogel.

A sight of self-assembly mechanism in fish oil oleogels: Phase transition, crystal structure and non-covalent interaction

Fish oils contain ω-3 polyunsaturated fatty acids (PUFAs), but easily cause quality deterioration due to the oxidation. Beeswax-based oleogels could wrap fish oils by beeswax self-assembly. The phase transition, crystal structure and non-covalent interaction were investigated to reveal the self-assembly mechanism from the perspective of beeswax and oil phase characteristics. The results indicated that high unsaturation degree, PUFAs and beeswax additions promoted phase transition, SFC and stable crystal networks. The changes of crystal structures were ascribed to the polymorphism and polymorphic transition. β-Polymorphs could form crystal networks, and β'-polymorphs could influence the size of crystal chains or clusters as well as crystalline domains. Crystalline domain sizes affected crystal morphologies and network structures, including plate-like structures and multi-layer porous structures. UFAs could involve the beeswax self-assembly to change structure characteristics by van der Waals forces and π-π stacking. The OBC remained 100%, when beeswax additions reached more than 6%. Hence, beeswax additions, PUFA contents and unsaturation degree all influenced the self-assembly mechanism and adjusted the macroscopic properties of oleogels.

Sugary and salty former food products in pig diets affect energy and nutrient digestibility, feeding behaviour but not the growth performance and carcass composition

Former foodstuff products (FFPs) are promising alternative ingredients for reducing the waste of natural resources and the environmental impact of food production. This study investigates the effects of salty and sugary FFPs on growth performance, apparent total tract digestibility (ATTD), and growing-finishing pigs' empty body and carcass composition. Thirty-six Swiss Large White male castrated pigs were assigned to three growing (G) and finishing (F) diets: (1) standard diet (ST), 0% FFPs; (2) 30% conventional ingredients replaced by sugary FFPs (SU); and (3) 30% conventional ingredients replaced by salty FFPs (SA). Faecal samples from 24 selected pigs were collected to assess the ATTD of gross energy, crude fibres, and CP. The BW was measured weekly, while feed intake was determined daily. Average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (FCR), and ATTD were calculated for both the growing and finishing periods. Pigs' body composition was determined at ≥20 and ≥98 kg using dual-energy X-ray absorptiometry. In the growing but not finishing period, the FCR was lower (P < 0.05) in ST compared to SA and SU pigs. Considering the entire growing and finishing period, neither the inclusion level nor the type of FFPs influenced (P > 0.05) ADG, ADFI, FCR, or BW at slaughter. In both the growing and finishing periods, the gross energy ATTD was higher (P < 0.05) in the SA than in the ST group, with intermediate values in the SU group. In the growing period, the CP ATTD was higher (P < 0.05) in the SA than in the SU and ST groups. In the finishing period, the crude fibre ATTD was lower (P < 0.05) in the SA and SU than in the ST group. Throughout the overall period, the average daily fat intake was higher (P < 0.05) in pigs fed an SU diet, even though both categories of FFPs had no (P > 0.05) effects on the parameters related to the pigs' body composition (e.g., average daily fat weight gain). Finally, the carcasses of the SU group had the thickest belly fat, even though the total fat content was similar among the groups. This study confirms that including FFPs has no detrimental effects on growth performance or live body/carcass composition in growing and finishing pigs.

Tiger Nut Oil-Based Oil Gel: Preparation, Characterization, and Storage Stability

In this study, Tiger nut (Cyperus esculentus L.) oil-based oleogels were prepared using the emulsion template method with whey protein (WPI; 0.5-2.5% (w/v) and Xanthan gum (XG; 0.1-0.5% (w/v). The microstructure of the oleogels obtained from the high internal phase emulsion (HIPE) and an emulsion after further shearing were observed using an optical microscope and laser confocal microscopy. A series of rheological tests were conducted to evaluate the effect of WPI and XG concentrations on the strength of the emulsion and oleogel. The texture, oil holding capacity, and oxidative stability of oleogels were characterized. The results showed that XG alone could not form oleogel, while the concentration of WPI had more effect than XG. When WPI was at a fixed concentration, the viscoelasticity of HIPE increased with the addition of XG. This was due to the complexation of WPI and XG, forming a stable gel network between the tight emulsion droplets and thus giving it a higher viscoelasticity. With an increase in WPI concentration, the stability and viscoelasticity of the emulsion were increased, and the oil-holding capacity and gel strength of the oleogels were enhanced. Moreover, the addition of XG could significantly enhance the stability and viscoelasticity of the emulsion (p < 0.05), and an increase in the concentration had a positive effect on it. The oleogels showed high gel strength (G' > 15,000 Pa) and good thixotropic recovery when the XG concentration was higher than 0.3% (w/v). WPI (2.0%) and XG (>0.3%) could be used to obtain HIPE with good physicochemical and viscoelastic properties, which in turn lead to oleogels with minimal oil loss, viscoelastic and thixotropic recovery, and temperature stability. Compared with tiger nut oil-based oleogel, tiger nut oil contained more polyunsaturated fatty acids, which were more easily decomposed through oxidation during storage and had lower oxidation stability. This study provides a reference for the preparation of oleogels from food-approved polymers and provides additional theoretical support for their potential application as solid fat substitutes.

Konjac glucomannan promoted fabrication of diacylglycerol oil-based oleogels through emulsion-templated approach: Comparison with triacylglycerol oleogels

Konjac glucomannan (KGM) combined with hydroxypropyl methyl cellulose was used to fabricate diacylglycerol oleogels (DGOs) through the emulsion-templated method, and compared with triacylglycerol oleogels (TGOs). The appearance and microstructure results showed that stable emulsions and oleogels could be formed in the presence of 0.2-0.6 wt% KGM. Higher KGM concentrations resulted in a stronger gel structure in oleogels, whose thixotropic recovery percentages were 50.45-75.20 %. From LF-NMR determination, the higher concentration of KGM presented earlier transverse relaxation (T2) time, and the T2 parameters of DGOs were higher than that of TGOs. Texture and oil loss analysis indicated that the mechanical strength and oil holding ability of DGOs were slightly lower than those of TGOs. This study demonstrated the advantages of biopolymers as thickening agents for obtaining stable emulsion and oleogels. The specific characteristics of DGOs distinguished from TGOs should be attributed to their different properties (unsaturation, viscosity, polarity, etc.) between the liquid oils.

Evaluation of high oleic sunflower oil oleogels with beeswax, beeswax-glyceryl monopalmitate, and beeswax-Span80 in cookie preparation

BACKGROUND

Shortening is used widely in cookie preparation to improve quality and texture. However, large amounts of saturated and trans fatty acids present in shortening have adverse effects on human health, and much effort has been made to reduce the use of shortening. The use of oleogels might be a suitable alternative. In this study, the oleogels of high oleic sunflower oil with beeswax (BW), BW-glyceryl monopalmitate (BW-GMP), and BW-Span80 (BW-S80) were prepared and their suitability to replace shortening in cookie preparation was evaluated.

RESULTS

The solid fat content of BW, BW-GMP, and BW-S80 oleogels was significantly lower than that of commercial shortening when the temperature was not higher than 35 °C. However, the oil-binding capacity of these oleogels was almost similar to that of shortening. The crystals in the shortening and oleogels were β' form mainly; however, the morphology of crystal aggregates in these oleogels was different from that of shortening. The textural and rheological properties of doughs prepared with the oleogels were similar, and clearly different from those of dough with commercial shortening. The breaking strengths of cookies made with oleogels were lower than that of cookies prepared with shortening. However, cookies containing BW-GMP and BW-S80 oleogels were similar in density and color to those prepared with shortening.

CONCLUSION

The textural properties and color of cookies with BW-GMP and BW-S80 oleogels were very similar to those of the cookies containing commercial shortening. The BW-GMP and BW-S80 oleogels could act as alternatives to shortening in the preparation of cookies. © 2023 Society of Chemical Industry.

Application of CO2 Gas Hydrates as Leavening Agents in Black-and-White Cookies

In this unprecedented study, the application of CO₂ gas hydrates (GH) as a leavening agent to produce black-and-white cookies by replacing ammonium bicarbonate is investigated. Ammonium bicarbonate, the principal leavening ingredient in black-and-white cookies, has been linked to the creation of a carcinogenic substance known as acrylamide. Three distinct GH concentrations, 20%, 40%, and 50%, were utilized to determine the necessary amount to obtain a good leavening effect. However, the abrupt reduction in temperature brought on by the addition of GH had an inadmissible effect on the cookie dough. Consequently, an innovative kneading method carried out in a closed mixing unit at a high temperature was developed. The specific volume of the cookies when employing 50% GH as a baking agent was more than half that produced when using ammonium bicarbonate. In the cookies with GH, the springiness and hardness, which are the quality-determining textural characteristics of the pastry, remained within an acceptable range. The amount of acrylamide was reduced from 24.8 µg/Kg to around 18 µg/Kg by this research. Therefore, the presented study demonstrates the possibility of using CO₂ GH as a leavening agent in black-and-white cookies and in other products for a healthier future.

Food-Grade Oleogels: Trends in Analysis, Characterization, and Applicability

Currently, a large number of scientific articles can be found in the research literature in the field focusing on the use of oleogels for food formulation to improve their nutritional properties. The present review focuses on the most representative food-grade oleogels, highlighting current trends in terms of the most suitable methods of analysis and characterization, as well as trends in their application as substitutes for saturated and trans fats in foods. For this purpose, the physicochemical properties, structure, and composition of some oleogelators are primarily discussed, along with the adequacy of oleogel incorporation for use in edible products. Analysis and characterization of oleogels by different methods are important in the formulation of innovative foods, and therefore, this review discusses the most recent published results regarding their microstructure, rheological and textural properties, and oxidative stability. Last but not least, issues related to the sensory properties of oleogel-based foods are discussed, highlighting also the consumer acceptability of some of them.

Sunflower Oil-based Oleogel as Fat Replacer in Croissants: Textural and Sensory Characterisation

Croissants are made using solid fats that predominantly contain saturated fatty acids and trans fatty acids. In this study, an oleogel consisting of sunflower oil structured with hydroxypropyl methylcellulose was used as a conventional fat replacer in puff pastry thus improving its nutritional profile. Oleogel (OG)-shortening (SH) blends were prepared as a fat replacer for partial (50, 60, 70%) and full shortening (100%) substitution. These replacements implied a reduction of up to 45% of saturated fat and an increase of up to 47% of unsaturated fat, especially monounsaturated fatty acids. Physical characterisation was conducted using texture profile analysis and penetration tests to evaluate the oleogel effect on a baked croissant matrix structure. Sensory analysis was also performed to evaluate the organoleptic properties of the croissant. Shortening replacement using oleogel resulted in croissants with lower saturated fat content, lower bite firmness, and a texture profile similar to croissants made with commercial shortening. The presence of oleogel up to 100% did not contribute negatively to the firmness or springiness of the croissants, although they became chewier and more cohesive as the oleogel increased. In terms of sensory perception, the SH50:OG50 croissant sample was the most similar to the solid fat control. The use of sunflower oil-cellulose-based oleogel was suitable for the formulation of puff pastry products with a healthier fat profile while maintaining the physical and sensory characteristics of conventional croissants.

Recent Advances in Cellulose-Based Hydrogels: Food Applications

In the past couple of years, cellulose has attracted a significant amount of attention and research interest due to the fact that it is the most abundant and renewable source of hydrogels. With increasing environmental issues and an emerging demand, researchers around the world are focusing on naturally produced hydrogels in particular due to their biocompatibility, biodegradability, and abundance. Hydrogels are three-dimensional (3D) networks created by chemically or physically crosslinking linear (or branching) hydrophilic polymer molecules. Hydrogels have a high capacity to absorb water and biological fluids. Although hydrogels have been widely used in food applications, the majority of them are not biodegradable. Because of their functional characteristics, cellulose-based hydrogels (CBHs) are currently utilized as an important factor for different aspects in the food industry. Cellulose-based hydrogels have been extensively studied in the fields of food packaging, functional food, food safety, and drug delivery due to their structural interchangeability and stimuli-responsive properties. This article addresses the sources of CBHs, types of cellulose, and preparation methods of the hydrogel as well as the most recent developments and uses of cellulose-based hydrogels in the food processing sector. In addition, information regarding the improvement of edible and functional CBHs was discussed, along with potential research opportunities and possibilities. Finally, CBHs could be effectively used in the industry of food processing for the aforementioned reasons.

Crystallization and Structural Properties of Oleogel-Based Margarine

Interest in oleogel as a promising alternative to traditional hydrogenated vegetable oil has increasingly grown in recent years due to its low content of saturated fatty acids and zero trans fatty acids. This study aimed to develop wax-based margarine to replace traditional commercial margarine. The wax-based margarine was prepared and compared with commercial margarine in texture, rheology, and microscopic morphology. The possibility of preparing margarine at room temperature (non-quenched) was also explored. The results showed that the hardness of oleogel-based margarine increased as the BW concentration increased. Denser droplets and crystal network structure were observed with the increase in BW content. XRD patterns of oleogel-based margarine with different content BW were quite similar and structurally to the β' form. However, the melting temperature of oleogel-based margarine was over 40 °C at each concentration, which represented a poor mouth-melting characteristic. In addition, the unique, improved physical properties of oleogel-based margarine were obtained with binary mixtures of China lacquer wax (ZLW) and Beeswax (BW), due to the interaction of the ZLW and BW crystal network. The rapid cooling process improved the spreadability of oleogel-based margarine. The margarine prepared by 5% BW50:ZLW50 had similar properties to commercial margarine in texture and melting characteristics (37 °C), which had the potential to replace commercial margarine.

A functional spreadable canola and milk proteins oleogels as a healthy system for candy gummies

Recently, interest and demand for healthy and useful food products have become a global requirement. Thus, the production of functional foods with high polyunsaturated fatty acids and antioxidants is very challenging. In this study, four functional spreadable oleogels based on canola oil and milk proteins were developed. These spreadable oleogels were used as an innovative model for the preparation of candy gummies. The chemical composition, oxidative stability, and effects of storage conditions were studied. The results showed that the fat content in spreadable oleogels and gummies ranged from 35 to 47 and 2.40–4.15%, respectively. The protein content in spreadable doum and carrot was 7.41%, while it was 6.15% in the spreadable plain and ranged from 10.25 to 12.78% in gummies. The hardness of spreadable oleogels and gummies ranged from 0.3 to 0.9 and 6.22–16.30 N, respectively. Spreadable carrot and spreadable doum had peroxide values greater than 8 meqO₂/kg after storage, whereas spreadable plain and spreadable canola oleogel had better oxidative stability. The antioxidant activity of spreadable oleogels and gummies ranged from 66.98–46.83% to 51.44–40.37%, respectively. In addition, transmission electron microscopy and polarized light microscopy micrographs showed the presence of a coherent entangled network between oleogels and nutritional polymers. The oil binding capacity of spreadable carrot oleogel had a maximum value of 97.89%, while formed gummies were higher than 99%. This study showed a promising way to make functional spreadable oleogels as a model for food products that are good for health and nutrition.

Hydrogels, Oleogels and Bigels as Edible Coatings of Sardine Fillets and Delivery Systems of Rosemary Extract

Edible coatings provide an alternative way to reduce packaging requirements and extend the shelf life of foods by delaying oxidation and microbial spoilage. Hydrogels, oleogels and bigels were applied as coatings on fresh sardine fillets. The effectiveness of these coatings as delivery systems of rosemary extract (RE) was also evaluated. Three groups of sardine fillet treatments were prepared: (i) the control (C), which comprised sardine fillets without coating, (ii) sardine fillets with plain hydrogel (H), oleogel (O) or bigel (BG) coatings, and (iii) sardine fillets with RE incorporated into the H, O and BG coatings. The different treatments were evaluated for lipid oxidation (TBA test), total volatile basic nitrogen (TVB-N) and microbiological growth during cold storage at 4 °C. Results showed that hydrogel, oleogel and bigel coatings delayed oxidation. The incorporation of RE into coatings significantly retarded lipid oxidation but did not affect the proliferation of microorganisms during storage. When RE was incorporated in the oleogel phase of the bigel coating, it produced significantly lower TVB-N values compared to the control and BG treatments. The incorporation of RE into the oleogel phase of the bigel coating may be a promising method of maintaining the storage quality of the sardine fillets stored at refrigerated temperatures.

Conversion of Pulse Protein Foam-Templated Oleogels into Oleofoams for Improved Baking Application

The food industry has long been searching for an efficient replacement for saturated-fatty-acid-rich fats for baking applications. Although oleogels have been considered a potential alternative for saturated and trans fats, their success in food application has been poor. The present study explored the use of oleofoams obtained by whipping the pulse protein foam-templated oleogels for cake baking. Oleogels were prepared at room temperature by adding canola oil containing high-melting monoglyceride (MAG) or candelilla wax (CW) to the freeze-dried pea or faba bean protein-stabilized foams. Oleogels were then whipped to create the oleofoams; however, only the oleogels containing MAG could form oleofoams. CW-oleogel could not form any oleofoam. The most stable oleofoams with the highest overrun, stability, and storage modulus were obtained from 3% MAG+pulse protein foam-templated oleogels. The MAG plus protein foam-templated oleogels showed smaller and more packed air bubbles than MAG-only oleofoam, which was ascribed to the protein's ability to stabilize air bubbles and provide a network in the continuous oil phase to restrict air bubble movement. A novel batter preparation method for oleofoam was developed to increase air bubble incorporation. The X-ray microtomography images of the cakes showed a non-homogeneous distribution of larger air bubbles in the oleofoam cake compared to the shortening cake although their total porosity was not much different. The oleofoam cakes made with the new method yielded similar hardness and chewiness compared to the shortening cakes. By improving rheology and increasing air incorporation in the batter, high-quality cakes can be obtained with MAG-containing oleofoams made from pulse protein foam-templated oleogels.

Identifying key factors and strategies for reducing oil content in fried instant noodles

Fried instant noodles have become a popular instant food in recent years, favored by consumers for their unique flavor and taste. Unfortunately, the oil content of instant noodles is generally high, so the rise of fat-related diseases poses a major health issue. From the perspective of the cost of instant noodle manufacturers and the health of consumers, it is of great significance to reduce the oil content of instant noodles. The aim of this review article is to provide an overview of the main factors, such as raw materials and production processes, affecting oil content in instant noodles in order to suggest specific strategies to reduce the oil content in the end product. From the literature reviewed, adding acetylated potato starch/carboxymethyl cellulose, hydroxypropyl methylcellulose, or preharvest-dropped apple powder in the noodle formulation could be a better choice to reduce oil uptake by 5%-20%. Instant noodles with lower oil content can be produced using novel alternative frying technologies, including microwave and vacuum frying. The proper management of the production processes and the implementation of enhancement strategies may result in a reduction of oil content in the end product.

Determination of characteristic evaluation indexes for novel cookies prepared with wax oleogels

BACKGROUND

Wax-based oleogels showed better performance as a substitute for shortening in cookies, but the relationship between the structure and physical properties of wax oleogels and cookies quality has not been elucidated, which limit its further application. In this regard, the effect of structure and physical properties of wax oleogels on the quality of cookies was investigated, and the characteristic indexes for evaluating the quality of novel cookies prepared with wax oleogels were determined.

RESULTS

The results showed that oleogels with 5-9% proportion of rice bran wax (RBX) and candelilla wax (CDW) produced soft cookies with porous structure, desired spread and color. Compared with shortening, wax oleogels with lower solid fat content (SFC, 4.5-11%, 25 °C) and higher β' crystals (2795.7-11 671.3) produced cookies with similar hardness to that of shortening. Besides, the hardness of wax oleogel-based cookies depends more on the amount of crystals than crystal size. In the results, SFC, β' crystals, viscosity and elastic modulus (G') were determined to be the characteristic evaluation indexes for the quality of cookies prepared with wax oleogels. Cookies with wax oleogels with higher SFC, β' crystal, viscosity and G' are softer.

CONCLUSION

The quality of novel cookies prepared with wax oleogels can be controlled by the SFC and β' crystal of wax oleogels. © 2022 Society of Chemical Industry.

Edible oleogels stabilized solely by stigmasterol: effect of oil type and gelator concentration

BACKGROUND

Phytosterols are considered to be one of the most promising gelators for obtaining oleogel because of their additional health benefits and natural coexist with vegetable oils. Previous studies have confirmed that individual phytosterols are not capable of structuring vegetable oils unless they act synergistically with other components. However, based on the self-assembly properties of stigmasterol (ST) in organic solvents, we speculate that it can also structure vegetable oils as a gelator alone.

RESULTS

For the first time, the present study confirmed the feasibility of using ST alone as a gelator for structuring of vegetable oils, including rapeseed oil (RSO), olive oil (OLO) and flaxseed oil (FSO). RSO had the lowest ST gelation concentration (4%, w/w), and the oil-binding capacity and firmness value of the oleogels were the highest. The rheological results showed that all the samples were gelatinous (G' > G″). The results of differential scanning calorimeter and X-ray diffraction further confirmed that the properties of RSO-based oleogels are superior to those prepared by OLO and FSO. The microscopic results also confirmed that the crystal structure of RSO oleogels was more uniform, smaller and more densely distributed.

CONCLUSION

The structural properties of the oleogels were positively correlated with the ST concentration, and various analysis indicators showed that the performance of the oleogel based on RSO was better than that of OLO and FSO. In summary, the present study used ST as a gelator to successfully prepare oleogels with excellent properties, which provides a feasible reference for researchers in related fields. © 2022 Society of Chemical Industry.

Heat- and shear-reversible networks in food: A review

While nature behaves like an irreversible network with respect to entropy and time, certain systems in nature exist that are, to some extent, reversible. The property of reversibility imparts unique benefits to systems that possess them, making them suitable for designing self-healing, stimuli-responsive, and smart materials that can be used in widely divergent fields. Reversible networks are currently being exploited for applications in tissue engineering, drug delivery, and soft robotics. They are also being utilized as low-calorie fat mimetics with melt-in-your-mouth textures, as well as being explored as potential scaffolds for three-dimensional (3D) printable food, among other applications. This review aims to gather representative examples of heat- and shear-reversible networks in the food science literature from the last 30 or so years, in other words, reversible food gels made either from linear biopolymers or from colloidal, particulate dispersions, including those that have been modified specifically to induce reversibility. An overview of the network mechanisms involved that impart reversibility, including a discussion of the strength and range of forces involved, will be highlighted. A model that explains why certain networks are thermoreversible while others are shear-reversible, and why others are both, will also be proposed. A fundamental understanding of these mechanisms will prove invaluable when designing reversible networks in the future, making possible the precise control of their properties, thus fostering innovative applications within the food industry and beyond.

Relationship between the microstructure and physical properties of emulsifier based oleogels and cookies quality

In this paper, the correlation between microstructure and physical properties of emulsifier based oleogels and qualities of cookies, as well as the key factors affecting cookies hardness was studied by using four kinds of food-grade emulsifiers with different concentrations. Monoacylglycerol (MAG) and sorbitan monostearate (SPAN) cookies showed similar hardness and L*, a*, b* to those of shortening cookies, in the concentration range of 6-15% and 12-18%, respectively, and their cross sections are uniformly porous. The solid fat content and α crystals content of emulsifier based oleogels showed no significant effect on cookie hardness. Besides, oleogel cookies prepared with emulsifier gelators with higher hydrophile-lipophile balance value showed lower hardness. In the results, higher shear viscosity (at 25 °C) of emulsifier based oleogels were determined to be the key factor for softer cookies. This study provides theoretical support for the quality control of novel cookies with emulsifier based oleogels.

Fat replacers in baked products: their impact on rheological properties and final product quality

Many baked products, except for bread, (i.e., cakes, cookies, laminated pastries, and so on) generally contain high levels of fat in their formulas and they require different bakery fats that impart product-specific quality characteristics through their functionalities. Even though, fat is crucial for baked product quality, strategies have been developed to replace fat in their formulas as high fat intake is associated with chronic diseases such as obesity, diabetes, and cardiovascular heart diseases. Besides, the solid bakery fats contain trans- and saturated fats, and their consumption has been shown to increase total and low-density lipoprotein cholesterol levels and to constitute a risk factor for cardiovascular diseases when consumed at elevated levels. Therefore, the aim of this review was to provide a detailed summary of the functionality of lipids/fats (endogenous lipids, surfactants, shortening) in different baked products, the rheological behavior of bakery fats and their contribution to baked product quality, the impact of different types of fat replacers (carbohydrate-, protein-, lipid-based) on dough/batter rheology, and on the quality characteristics of the resulting reduced-fat baked products.

Effect of flaxseed gum on the brittleness of oleogels based on candelilla wax

The present study aimed to decrease the brittleness of flaxseed oleogels based on candelilla wax (CLW) in combination with flaxseed gum (FG). Effects of flaxseed gum concentrations (0–0.4%) on the characteristics of flaxseed oleogels including oil binding capacity, textural, thermal, and rheological properties, and crystal polymorphisms were investigated. Higher concentrations (≥0.2%) of FG significantly decreased the textural parameters (e.g., hardness, fracturability) of oleogels (p < 0.05), suggesting that FG could decrease brittleness. Rheological results indicated that all flaxseed oleogels exhibited solid-like characteristics because the elastic modulus was larger than the viscous modulus. The elastic modulus of flaxseed oleogels presented a maximum value at 0.1% gum concentration. Any increase in gum concentration beyond this concentration decreased the elastic modulus. Increasing FG concentration up to 0.4% decreased the enthalpy of flaxseed oleogels during the melting process. The β′-polymorphic form is an orthorhombic perpendicular (O_⊥) subcell structure. Similar β′ crystal forms were observed among flaxseed oleogels, indicating that FG did not affect them negatively. The study showed that the physical properties of flaxseed oleogels based on CLW could be significantly changed by FG addition. These results provided a deeper comprehension of the novel system, which should be considered a new way to obtain healthy fats with better plasticity for food applications.

Oleogels using candelilla wax as a gelling agent and flaxseed gum as a structural modifier: preparation and characterization.

Development of Antioxidant-Fortified Oleogel and Its Application as a Solid Fat Replacer to Muffin

Oleogelation has recently received a great deal of attention in the food industry as a novel alternative technology that physically converts liquid oil into semi-solid gel. Since the functional characteristics of oleogels are dependent on the gelators or bioactive compounds incorporated, this study was undertaken to evaluate the rheological properties and oxidative stability of candelilla wax oleogels fortified with glycerol monostearate (GMS) and β-carotene, and also to investigate their applications to muffin as a shortening replacer. The interaction between candelilla wax and GMS contributed to strengthening the oleogel structure. The oleogels with β-carotene showed the lowest peroxide values than the other samples. The muffins prepared with oleogels for shortening had greater specific gravity and harder texture, but there was no significant difference in the specific volume between the shortening and oleogel samples with GMS. In addition, muffins with β-carotene oleogels showed the highest oxidative stability. Therefore, this study indicated that the incorporation of β-carotene and GMS in oleogels positively affected the storage stability of muffin.

Use of Oleogels to Replace Margarine in Steamed and Baked Buns

Bakery products are usually formulated with solid fats, like margarines and shortenings, which contain high levels of saturated and trans-fatty acids and have negative effects on human health. In this study, hydroxypropyl methylcellulose (HPMC) and xanthan gum (XG) were used as oleogelators to prepare oleogels, using sunflower and olive oil, as substitutes for margarine in baked or steamed buns. The effect of oleogels on the physical properties of the buns was evaluated by analyzing the crumb structure, specific volume, height, and texture. In addition, a triangular discriminatory sensory test was conducted, and lipid digestibility was assessed through in vitro digestion studies. Replacement of margarine with oleogels produced steamed buns with no differences in the crumb structure, volume, height, and texture; however, in baked buns, a less porous and harder structure was produced. No differences in texture were observed between the margarine buns and buns made with oleogels when the triangular test was conducted. The extent of lipolysis was not affected when margarine was replaced by oleogels in the baked and steamed buns. The results suggest that using oleogels instead of margarine in buns could represent an interesting strategy to prepare healthier bakery products.

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.

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.

Amelioration of the stability of polyunsaturated fatty acids and bioactive enriched vegetable oil: blending, encapsulation, and its application

Lipid oxidation in vegetable oils is the primary concern for food technologists. Modification of oils like hydrogenation, fractionation, inter-esterification, and blending are followed to improve nutritional quality. Blending non-conventional/conventional vegetable oils to obtain a synergistic oil mixture is commonly practiced in the food industry to enhance the nutritional characteristics and stability of oil at an affordable price. Microencapsulation of these oils provides a functional barrier of core and coating material from the adverse environmental conditions, thereby enhancing the oxidative stability, thermo-stability, shelf-life, and biological activity of oils. Microencapsulation of oils has been conducted and commercialized by employing different conventional methods including emulsification, spray-drying, freeze-drying, coacervation, and melt-extrusion compared with new, improved methods like microwave drying, spray chilling, and co-extrusion. The microencapsulated oil emulsion can be either dried to easy-to-handle solids/microcapsules, converted into soft solids, or enclosed in a gel-like matrix, increasing the shelf-life of the liquid oil. The omega-rich microcapsules have a wide application in confectionery, dairy, ice-cream, and pharmaceutical industries. This review summarizes recent developments in blending and microencapsulation technologies in improving the stability and nutritional value of edible oils.

Heat resistant chocolate development for subtropical and tropical climates: a review

Heat resistant chocolate (HRC) which can retain the desired texture and mouthfeel in tropical and subtropical climatic conditions has become a major research area in the chocolate industry. Liking of the chocolate products keeps on changing with the geographical conditions of the world due to the availability of ingredients from local resources and consumer's taste preferences. The geographical changes also bring about the change in climatic conditions and as such no chocolates have been formulated to withstand the hot tropical or sub-tropical temperature conditions. Textural issues and various storage related problems faced due to meltability of chocolate in different countries has opened up a broad research field of sustainable HRC manufacturing. Over the years, there are broadly three different approaches (fat modification, sugar structure modification and innovative process approach) to develop the HRC and all these scientific approaches have given different scientific insights about improving the heat resistance characteristics and textural stability of chocolate. There is a lack or coordinated fundamental and applied research related to cocoa butter polymorphism, and thermal-textural issues during product development/storage. This review paper is an attempt to describe the different scientific approaches for developing HRC and how they affect the physical/sensory chocolate attributes.

The Effect of Cooling Rate on the Microstructure and Macroscopic Properties of Rice Bran Wax Oleogels

The main purpose of this paper is to study the microstructure and macroscopic characteristics of rice bran wax (RBW) oleogels at a cooling rate of 1°C/min and 10°C/min by polarized light microscopy, X-ray diffraction, differential scanning calorimetry, texture analyzer, and micro rheometer. The oleogels of soybean oil were prepared by RBW in concentrations of 5%, 7.5%, 10%, 15% and 20% (wt/wt). The results of this study indicated that the concentration of RBW and cooling rates were affected by the crystal size and spatial distribution of these crystals. For the same RBW concentration, oleogels contained smaller crystals when cooled at 10°C/min compared to 1°C/min. And the oleogels obtained at a rate of 10°C/min exhibited a tighter crystal network, lower melting point, harder texture, and energy storage modulus. These results demonstrated the impact of cooling rate on the rheological behavior, nucleation, and crystallization process.