Oil-in-water emulsion gels stabilized with chia (Salvia hispanica L.) and cold gelling agents: Technological and infrared spectroscopic characterization

Sodium caseinate‑sodium alginate binary complex stabilized W1/O/W2 emulsion gels loaded with proanthocyanidins from Aronia melanocarpa (Michx.) Elliott: Formation, structure, stability, in vitro gastrointestinal digestion

This study developed a W1/O/W2 emulsion gel encapsulating proanthocyanidins from Aronia melanocarpa (Michx.) Elliott (APC) using polyglycerol ricinoleate (PGPR) as the lipophilic emulsifier and sodium caseinate (NaCN)-alginate (Alg) as the hydrophilic emulsifier. The optimal preparation process was established based on particle size, zeta potential, phase separation, centrifugal stability, and microscopic morphology: 4.5 % PGPR concentration, a W1:O phase mass ratio of 3:7, 0.6 % NaCN concentration, and a W1/O:W2 mass ratio of 3:7. The influence of varying Alg concentrations on the microstructure, gel properties, stability, and in vitro digestibility of the emulsion gels was then investigated. Results indicated that NaCN-Alg emulsion gels with 0.8 % Alg exhibited uniform structure distribution, excellent elasticity, and deformation resistance, with an APC encapsulation efficiency of (98.09 ± 0.11)%. The addition of Alg enhanced the thermal and storage stability of the emulsion gel. After 28 days of storage, the gel with 0.8 % Alg demonstrated superior water retention and pH stability. During in vitro digestion, Alg slowed the hydrolysis of NaCN and oil droplets, improving the bioaccessibility and bioavailability of APC. These findings provide a foundation for applying NaCN-Alg emulsion gels in low-fat food products.

Sodium caseinate/cellulose nanofiber-stabilized Pickering emulsions: A study on lipid absorption regulation

This study aimed to develop a sustainable and bio-based nano-additive (sodium caseinate/cellulose nanofibers (SC/CNF) complex) to modulate liquid-based oil-in-water (O/W) colloid interfaces, which function as a fat control agent to slow lipid digestion. Edible protein (SC) was grafted onto CNF through facile electrostatic attraction, which reduces solvent and chemical usage for greener process. The physicochemical properties of SC/CNF showed that adding SC increased the interfacial bonding between CNF particles, resulting in higher interfacial pressure by forming dense and compact layers of SC/CNF. This characteristic improves the mechanical strength and colloidal stability of SC/CNF during water-oil stabilization. Further preparation of O/W Pickering emulsions stabilized by SC/CNF complexes was conducted using different parameters (such as SC concentration, dosage of SC/CNF, and O/W ratio) to investigate profile of free fatty acid (FFA) released during lipid digestion via simulated in vitro gastrointestinal tract (GIT) model. The results showed that the optimized emulsion stabilized by the SC/CNF complex rendered a lower value of free fatty acids (FFA) after undergoing in vitro simulated digestion. The lowest FFA release (31.18 %) was achieved under the following conditions: 1 % w/v (SC concentration), 1 % w/w (dosage of SC/CNF), and 20/80 (O/W) ratio. Low FFA release within the digestive system indicated that the nano-emulsions effectively regulated lipid digestion. The changes in physicochemical characteristics in terms of colloidal stability (particle size, microstructure, and surface charge) of the stabilized emulsions corresponding to the FFA released were studied during each digestion phase (including mouth, stomach, and small intestine). This study revealed that the SC/CNF complex is a promising nano-biomaterial that can function as a bio-functional food additive, particle stabilizer, and fat digestion controller. The unique characteristics of SC/CNF complexes in stabilizing oil-water emulsions present a potential interfacial mechanism for modulating lipid bioavailability. The innovation approach allows for the demand for green-label products, promote development of healthier food options, and the pursuit of sustainable food solutions.

Utilizing chia flour-based gelled emulsion for the development of functional beef patties with enhanced nutritional profile

This study evaluated chia flour, egg white powder, and peanut oil gelled emulsion (GE) as a fat replacer in beef patties. Four formulations were prepared, replacing beef fat with different levels of gelled emulsion: 0% (C), 50% (G50), 75% (G75), and 100% (G100). The beef patties with GE showed improved nutritional properties, technological parameters, and cooking characteristics. A remarkable reduction in SFAs was achieved with the substitution of beef fat by the GE, with reductions of 33.71%, 46.64%, and 72.04% for 50%, 75%, and 100% substitution levels, respectively. AI and TI indices decreased, indicating healthier profiles. Reformulated samples exhibited lower hardness, gumminess, and chewiness values. Color and appearance were similar to the control, with higher sensory scores for G75 and G100. GE impacted color parameters, increasing L* and b* values. The utilization of GE effectively minimized voids in the beef patty structure, leading to improved cooking yield and a more compact structure. GE influenced oxidative stability, with average onset temperatures of 126.33°C (50% GE), 140.58°C (75% GE), and 127.04°C (100% GE). In conclusion, gelled emulsions could successfully contribute to producing healthier meat products.

Blackcurrant Pomace Extract as a Natural Antioxidant in Vienna Sausages Reformulated by Replacement of Pork Backfat with Emulsion Gels Based on High Oleic Sunflower and Flaxseed Oils

The incorporation of a blackcurrant pomace extract (BPE) at 2.5%, 5.0% and 10.0% into an emulsion gel based on high oleic sunflower and linseed oils was examined in order to obtain a functional ingredient to be used as a pork backfat replacer in Vienna sausages. The replacement of the pork backfat with the control emulsion gel reduced the cooking loss but negatively affected the color by decreasing L* and a* values as compared with the traditional product. A decrease in the n-6/n-3 ratio from 10.99 to around 1.54 (by 7 times) was achieved through reformulation, while the PUFA/SFA ratio increased from 0.49 to 1.09. The incorporation of BPE did not have a major impact on the fatty acid profile and improved color by increasing redness, but negatively affected the texture by increasing hardness, gumminess and share force as compared with the sausages reformulated without extract. BPE reduced the pH and the thermal stability of the emulsion gels, increased cooking loss and decreased moisture retention in sausages. BPE increased the oxidative stability of Vienna sausages enriched in polyunsaturated fatty acids; however, the incorporation of BPE into the emulsion gels above 5% affected the sensory scores for appearance, texture and general acceptability of the reformulated sausages.

Alginate/whey protein isolate-based emulgel as an alternative margarine replacer in processed cheese: Impact on rheological, mechanical, nutritional, and sensory characteristics

The effects of partial or full replacement of margarine by alginate/whey protein isolate-based olive oil emulgel on nutritional, physicochemical, mechanical, and rheological properties of processed cheese (PC) were investigated in this work. All formulated samples had the same amount of total fat, DM, and pH. According to the results of the fatty acids profile, the PC sample in which the margarine was fully replaced by the emulgel (EPC100) had the highest (49.84%) oleic acid content and showed a reduction of 23.7% in SFA compared with the control sample (EPC0; formulated just with margarine). In addition, EPC0 had the highest hardness among various cheese samples, which was also confirmed by its compact microstructure. Dynamic oscillatory measurements revealed that EPC100 had the highest crossover strain (or resistance to deformation). The high rigidity of this sample was related to the 3-dimensional structure of emulgel. According to the creep test results, EPC100 showed the lowest relative recovery (flowability). A high temperature dependency of viscoelastic moduli was observed in EPC0 at 42°C. No significant differences were observed between the color attributes and sensory properties of the various cheese samples. Alginate/whey protein isolate-based olive oil emulgel can be considered as a healthy margarine replacer in PC.

Novel fungal alternative proteins from Penicillium limosum for enhancing structural and functional properties of plant-based meat analogues

Fungal proteins are excellent novel protein resources due to their high nutritional value and biological activity. In this study, a non-toxic strain of Penicillium limosum with a high biomass yield, protein, and essential amino acid contents, was isolated from wheat Qu (solid-state fermentation starter culture). Pea protein isolate (PPI) and P. limosum mycelial protein powder were extruded to prepare high-moisture meat analogues (HMMA), and their structural and functional properties were evaluated. Compared with 100% PPI, the addition of 5% mycoprotein enhanced the viscosity, gelling properties, chewiness, fibrous degree and in vitro protein digestibility (68.65%) of HMMA. Protein aggregates formed during high temperature extrusion, which increased the oil absorption capacity of HMMA (5% MY substitution). Conversely, their water absorption capacity indices were reduced by 5%. These findings provide a theoretical basis for the functional application of novel fungal alternative proteins.

Rheology, physicochemical properties, and microstructure of fish gelatin emulsion gel modified by γ-polyglutamic acid

In this work, the effect of the addition of γ-polyglutamic acid (γ-PGA) on the rheology, physicochemical properties, and microstructure of fish gelatin (FG) emulsion gel was investigated. Samples of the emulsion gel were evaluated for rheological behavior and stability prior to gelation. The mechanical properties and water-holding capacity (WHC) of the emulsion were determined after gelation. The microstructure of the emulsion gel was further examined using confocal laser scanning microscopy (CLSM). The results indicated a gradual increase in the apparent viscosity and gelation temperature of the emulsion at a higher concentration of γ-PGA. Additionally, frequency scan results revealed that on the addition of γ-PGA, FG emulsion exhibited a stronger structure. The emulsion containing 0.1% γ-PGA exhibited higher stability than that of the control samples. The WHC and gel strength of the emulsion gel increased on increasing the γ-PGA concentration. CLSM images showed that the addition of γ-PGA modified the structure of the emulsion gel, and the droplets containing 0.1% γ-PGA were evenly distributed. Moreover, γ-PGA could regulate the droplet size of the FG emulsion and its size distribution. These findings suggest that the viscoelasticity and structure of FG emulsion gels could be regulated by adjusting the γ-PGA concentration. The γ-PGA-modified FG emulsion gel also exhibited improved rheology and physicochemical properties. The results showed that γ-PGA-modified FG emulsion gel may find potential applications in food, medicine, cosmetics, and other industries.

Assembly of soy protein-corn starch composite gels by thermal induction: Structure, and properties

The effect of different corn starch (CS) concentrations on the gel formation of soybean isolate protein (SPI) was investigated. Moreover, the texture, rheological properties of the gel were determined, and the spatial structure and interactions of the composite gel system were analyzed. The composite system transitioned from liquid to solid-like with an increase in the CS concentration and did not backflow when inverted for 24 h. With the addition of CS, the gel strength, water holding capacity (WHC), G', and G'' increased significantly. The maximum was reached at 10 % starch concentration with gel strength of (228.96 ± 29.86) g and WHC of (98.93 ± 2.02)  %. According to low-field 1H nuclear magnetic resonance (LF-NMR) results, CS has a high water absorption capacity, which improved the WHC. The scanning electron microscopy results revealed that composite gels with a high CS concentration had a more dense and small void network structure. According to the results of molecular force interaction, infrared spectroscopy, Raman spectroscopy, and free sulfhydryl group analysis, the added starch promoted the unfolding of SPI molecules, exposure of hydrophobic groups, transformation of free sulfhydryl groups into disulfide bonds, and hydrogen bond formation. Hydrophobic interactions, disulfide bonding, and hydrogen bonding function together to form the SPI-CS composite gel system. The study results provide the basis for applying soy protein and CS gels.

Comprehensive investigation into the effects of yeast dietary fiber and temperature on konjac glucomannan/kappa-carrageenan for the development of fat analogs

In this study, yeast dietary fiber (YDF) was incorporated into konjac glucomannan/kappa-carrageenan (KGM/κ-KC) for the development of fat analogs, and the impact of YDF on the gelation properties and behavior of KGM/κ-KC composite gels was assessed. YDF improved the composite gel whiteness value, and affected the mechanical properties of the composite gel, especially enhancing its hardness, and decreasing its chewiness, elasticity, and gel strength, making it more similar to porcine back fat. When the yeast dietary fiber content was 0.033 g/mL and the heating temperature was 80 °C (T80-2), the textural properties of the composite gel were closest to porcine back fat. The frequency sweep results suggested that YDF incorporation led to enhancement of the intermolecular interaction and intermixing and interaction among more easily at higher processing temperatures (80 °C and 90 °C). By scanning electron microscopy, the fatty surface of porcine back fat was flat and covered with a large amount of oil, while KGM/κ-KC/YDF composite gels developed a dense, stacked network structure. YDF caused more fragmented, folded, and uneven structures to emerge. Overall, YDF could influence the gel behavior of KGM/κ-KC composite gels, and change their colors and mechanical properties. This work could serve as a guide for preparing fat analogs with KGM/κ-KC composite gels.

Efficacy of Chitosan, Pectin and Xanthan as Cold Gelling Agents in Emulsion Gels Stabilized with Legume Proteins to Be Used as Pork Backfat Replacers in Beef Burgers

This study aimed to develop stable emulsion gels enriched in polyunsaturated fatty acids, formulated with a mixture of olive (75%) and linseed (25%) oils, by incorporating two different stabilizers-pea and soy protein isolates-and three different cold gelling agents-chitosan, pectin and xanthan-to be used as pork backfat replacers in beef burgers. The color, pH, stability and textural properties of the emulsion gels were analyzed as affected by cold storage (4 °C, 7 days). Proximate composition, fatty acid content, technological and sensory properties were determined after burger processing. Meanwhile, color, pH, textural parameters and lipid oxidation were monitored in burgers at 0, 5 and 10 days of storage at 4 °C. A reduction of the fat content between 21.49% and 39.26% was achieved in the reformulated burgers as compared with the control, while the n-6/n-3 polyunsaturated fatty acid ratio decreased from 5.11 to 0.62. The highest moisture and fat retention were found in reformulated burgers made with xanthan, both with pea and soy proteins; however, their textural properties were negatively affected. The reformulated burgers made with chitosan were rated highest for sensory attributes and overall acceptability, not significantly different from the controls.

A comparative study of the impacts of preparation techniques on the rheological and textural characteristics of emulsion gels (emulgels)

A subtype of soft solid-like substances are emulsion gels (emulgels; EGs). These composite material's structures either consist of a network of aggregated emulsion droplets or a polymeric gel matrix that contains emulsion droplets. The product's rheological signature can be used to determine how effective it is for a specific application. The interactions between these structured system's separate components and production process, however, have a substantial impact on their rheological imprint. Therefore, rational comprehension of interdependent elements, their structural configurations, and the resulting characteristics of a system are essential for accelerating our progress techniques as well as for fine-tuning the technological and functional characteristics of the finished product. This article presents a comprehensive overview of the mechanisms and procedures of producing EGs (i.e., cold-set and heat-set) in order to determine the ensuing rheological features for various commercial applications, such as food systems. It also describes the influence of these methods on the rheological and textural characteristics of the EGs. Diverse preparation methods are the cause of the rheological-property correlations between different EGs. In many ways, EGs can be produced using various matrix polymers, processing techniques, and purposes. This may lead to various EG matrix structures and interactions between them, which in turn may affect the composition of EGs and ultimately their textural and rheological characteristics.

Reformulation of Bologna Sausage by Total Pork Backfat Replacement with an Emulsion Gel Based on Olive, Walnut, and Chia Oils, and Stabilized with Chitosan

Bologna sausage, also called "la grassa", is a very popular meat product despite its high fat content and lipidic profile raising serious negative health concerns. An emulsion gel containing olive, walnut, and chia oils, stabilized with soy protein isolate, transglutaminase, and chitosan, was used as total pork backfat replacer in Bologna sausage. The nutritional, textural, and technological properties were assessed and sensory analyses were conducted. Color, pH, and lipid oxidation were monitored during 18 days of cold storage (4 °C). A normal fat Bologna sausage was used as a control reference. A decrease in the n-6/n-3 ratio from 16.85 to 1.86 (by 9 times) was achieved in the reformulated product as compared with the control, while the PUFA/SFA ratio increased from 0.57 to 1.61. Color measurements indicated that the lightness and yellowness increased while redness slightly decreased in the reformulated product. The total substitution of pork backfat in Bologna sausage by the emulsion gel developed in the present study was realized without significantly affecting the technological properties, the oxidative stability and the overall acceptance by the consumers.

Impact of Silicon Addition on the Development of Gelled Pork Lard Emulsions with Controlled Lipid Digestibility for Application as Fat Replacers

Pork lard gelled emulsions stabilized with two proteins [soy protein concentrate (SPC) or a pork rind protein extract (PRP)], both with and without added silicon (Si) from diatomaceous earth powder, were gelled by microbial transglutaminase and к-carrageenan. These gelled emulsions (GEs), intended as fat replacers, were evaluated in different aspects, including microstructure and technological properties during chilling storage. In addition, in vitro gastrointestinal digestion (GID) with an analysis of lipolysis and lipid digestibility was also evaluated. All GEs showed adequate technological properties after 28 days of chilling storage, although the SPC-stabilized GEs showed better gravitational and thermal stability (~4% and ~6%, respectively) during chilling storage than the PRP-stabilized ones (~8 and ~12%, respectively). PRP developed larger flocculates restricting pancreatic lipase-mediated lipolysis during intestinal digestion. The addition of Si to both GE structures protected them against disruption during in vitro digestion. Accordingly, Si appears to slow down fat digestion, as reflected by higher triacylglycerides content after GID (15 and 22% vs. 10 and 18% in GEs without Si) and could become a potential candidate for use in the development of healthier meat products.

Membrane Emulsification as an Emerging Method for Lacticaseibacillus rhamnosus GG® Encapsulation

Techniques capable of producing small-sized probiotic microcapsules with high encapsulation yields are of industrial and scientific interest. In this study, an innovative membrane emulsification system was investigated in the production of microcapsules containing Lacticaseibacillus rhamnosus GG® (Lr), sodium alginate (ALG), and whey protein (WPI), rice protein (RPC), or pea protein (PPC) as encapsulating agents. The microcapsules were characterized by particle size distribution, optical microscopy, encapsulation yield, morphology, water activity, hygroscopicity, thermal properties, Fourier-transform infrared spectroscopy (FTIR), and probiotic survival during in vitro simulation of gastrointestinal conditions. The innovative encapsulation technique resulted in microcapsules with diameters varying between 18 and 29 μm, and encapsulation yields > 93%. Combining alginate and whey, rice, or pea protein improved encapsulation efficiency and thermal properties. The encapsulation provided resistance to gastrointestinal fluids, resulting in high probiotic viability at the end of the intestinal phase (> 7.18 log CFU g-1). The proposed encapsulation technology represents an attractive alternative to developing probiotic microcapsules for future food applications.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11947-023-03099-w.

Fabrication of grape seed proanthocyanidin-loaded W/O/W emulsion gels stabilized by polyglycerol polyricinoleate and whey protein isolate with konjac glucomannan: Structure, stability, and in vitro digestion

In this work, the effects of konjac glucomannan (KGM) concentrations on microstructure, gel properties, stability and digestibility of water-in-oil-in-water emulsion gels stabilized by polyglycerol polyricinoleate and whey protein isolate were investigated. Visual appearance indicated that a non-layered double emulsion gel was formed when KGM increased to 0.75%. Emulsion gels with 1.5% KGM showed the highest encapsulation, freeze-thaw and photochemical stability due to the formation of the smallest droplets, which were supported by microscopic observations. Moreover, the addition of KGM improved water holding capacity, rheological and texture properties of emulsion gels. Particularly, at 1.5% or 1.75% KGM, color and potential of hydrogen showed the most stable level after 14 days of storage. During in vitro digestion, KGM delayed the hydrolysis of protein and oil droplets, and then improved the bioavailability of grape seed proanthocyanidin. These results promoted the application of KGM in emulsion gels and the encapsulation of nutraceuticals.

Structure and rheological properties of extruded whey protein isolate: Impact of inulin

Impacts of inulin addition (0, 5, 10, 15 %) on structure, functional and rheological properties of whey protein isolate (WPI) after extrusion pretreatment (E-WPI) were investigated. The results proved that after adding 15 % inulin, water holding capacity of gels, emulsifying activity, emulsion stability, foaming ability and foaming stability of E-WPI were the best and increased by 24.38 %, 7.43 %, 12.35 %, 162.97 % and 41.31 %, compared with those of unextruded WPI, respectively. Rheology analysis showed that apparent viscosity and consistency index of all the samples after inulin addition were enhanced and exhibited pseudoplastic fluids. FTIR spectroscopy indicated that E-WPI/WPI and inulin was linked together due to hydrogen bonds and addition of inulin increased the proportion of their β-turn structure. These findings demonstrated that the addition of inulin in combination with extrusion pretreatment could jointly improve the functional properties of WPI. Therefore, E-WPI with the addition of inulin shows potential commercial applications in the production of novel food foaming agents and emulsifiers.

Effects of Pork Backfat Replacement with Emulsion Gels Formulated with a Mixture of Olive, Chia and Algae Oils on the Quality Attributes of Pork Patties

This paper reports on the development of new emulsion gels containing a mixture of olive, chia and algae oil emulsified with soy protein isolate and stabilized by two different cold gelling agents, gelatin (EGEL) and chitosan (ECHIT), and to evaluate their potential use as pork backfat replacers in cooked pork patties. Reformulated patties were produced by half and full pork backfat replacement and compared to normal fat patties and reduced fat content patties made by replacing half of the added fat with water. Color parameters, pH and thermal stability of the emulsion gels were determined at processing and after 10 days of refrigerated storage. Proximate composition, fatty acid profile, technological properties and sensory attributes were evaluated after patty processing, while color parameters, pH and lipid oxidation were monitored in patties during 15 days of refrigerated storage (4 °C). Reformulated patties showed significant improvements of the lipid profile (lower saturated fatty acid content and n-6/n-3 ratio and higher long-chain polyunsaturated fatty acid content) as compared to the controls. In terms of technological properties, chitosan was more effective than gelatin as a stabilizer of the emulsion gel. All reformulated patties showed a good evolution of lipid oxidation during storage and acceptable sensory attributes.

Emulsion Gels Formed by Electrostatic Interaction of Gelatine and Modified Corn Starch via pH Adjustments: Potential Fat Replacers in Meat Products

The application of emulsion gels as animal fat replacers in meat products has been focused on due to their unique physicochemical properties. The electrostatic interaction between proteins and polysaccharides could influence emulsion gel stability. This study aimed to evaluate the physicochemical properties of emulsion gels using starch and gelatin as stabilizers, promoting electrostatic attraction via pH adjustment. Three systems were studied: emulsion gel A (EGA) and emulsion gel B (EGB), which have positive and negative net charges that promote electrostatic interaction, and emulsion gel C (EGC), whose charge equals the isoelectric point and does not promote electrostatic interactions. There was no significant difference in proximate analysis, syneresis and thermal stability between samples, while EGA and EGB had higher pH values than EGC. The lightness (L*) value was higher in EGA and EGB, while the yellowness (b*) value was the highest in EGC. The smaller particle size (p < 0.05) in EGA and EGB also resulted in higher gel strength, hardness and oxidative stability. Microscopic images showed that EGA and EGB had a more uniform matrix structure. X-ray diffraction demonstrated that all the emulsion gels crystallized in a β′ polymorph form. Differential scanning calorimetry (DSC) revealed a single characteristic peak was detected in both the melting and cooling curves for all the emulsion gels, which indicated that the fat exists in a single polymorphic state. All emulsion gels presented a high amount of unsaturated fatty acids and reduced saturated fat by up to 11%. Therefore, the emulsion gels (EGA and EGB) that favored the electrostatic protein-polysaccharide interactions are suitable to be used as fat replacers in meat products.

Oil-in Water Vegetable Emulsions with Oat Bran as Meat Raw Material Replacers: Compositional, Technological and Structural Approach

The unique composition and technological properties of some oat bran components (mainly protein and soluble fiber) and olive oil make them a good choice to form oil-in-water vegetable emulsions. The different concentrations of oat bran were studied to form olive oil-in water (O/W) emulsions to apply as a replacement for fat and meat. As a result, four O/W emulsions (OBE) were formulated with 10% (OBE10), 15% (OBE15), 20% (OEB20), and 30% (OBE30) oat bran concentrations and 40% olive oil, with the corresponding amount of water added for each O/W emulsion. Composition, technological properties (thermal stability, pH, texture), and lipid structural characteristics were evaluated. The results showed that low oat bran content (OEB10)-with a lower concentration of oat protein and β-glucans-resulted in an O/W emulsion with an aggregated droplet structure and lower thermal stability and hardness. These connections between composition, technology, and structural properties of olive O/W emulsions elaborated with oat bran could help in making the optimal choice for their potential application in the production of foods such as healthier meat products.

Encapsulation and sustained release of curcumin by hawthorn pectin and Tenebrio Molitor protein composite hydrogel

In this study, the effects of pH value, mixing ratio and the Ca²⁺ concentration on the complex gelation of hawthorn pectin (HP) and Tenebrio Molitor protein (TMP) were investigated. The turbidity results showed that the composite gel had the maximum polymer concentration when the mixing ratio was 2:1 and the pH value was 3.35. The rheological measurement results showed that TMP/HP (15 mmol/L) hydrogel (THIH) had the highest storage modulus and loss modulus, indicating that the properties of the hydrogel at this Ca²⁺ concentration had been significantly improved. The results of scanning electron microscope and pore size also proved that the network structure prepared under this condition was compact and uniform, the pore size was small, which was beneficial to the entrapment of active components. Subsequently, in order to explore the storage stability and antioxidant activity of THIH-loaded curcumin in simulated gastrointestinal environment, in vitro simulated digestion experiment was carried out and satisfactory results were obtained. To sum up, THIH was a promising delivery system with broad application prospects, which was expected to provide a novel idea for the entrapment and delivery of active components.

Application of Emulsion Gels as Fat Substitutes in Meat Products

Although traditional meat products are highly popular with consumers, the high levels of unsaturated fatty acids and cholesterol present significant health concerns. However, simply using plant oil rich in unsaturated fatty acids to replace animal fat in meat products causes a decline in product quality, such as lower levels of juiciness and hardness. Therefore, it is necessary to develop a fat substitute that can ensure the sensory quality of the product while reducing its fat content. Consequently, using emulsion gels to produce structured oils or introducing functional ingredients has attracted substantial attention for replacing the fat in meat products. This paper delineated emulsion gels into protein, polysaccharide, and protein–polysaccharide compound according to the matrix. The preparation methods and the application of the three emulsion gels as fat substitutes in meat products were reviewed. Since it displayed a unique separation structure, the double emulsion was highly suitable for encapsulating bioactive substances, such as functional oils, flavor components, and functional factors, while it also exhibited significant potential for developing low-fat or functional healthy meat products. This paper summarized the studies involving the utilization of double emulsion and gelled double emulsion as fat replacement agents to provide a theoretical basis for related research and new insight into the development of low-fat meat products.

Are quinoa proteins a promising alternative to be applied in plant-based emulsion gel formulation?

Emulsion gels are structured emulsion systems that behave as soft solid-like materials. Emulsion gels are commonly used in food-product design both as fat replacers and as delivery carriers of bioactive compounds. Different plant-derived proteins like soy, chia, and oat have been used in emulsion gel formulation to substitute fat in meat products and to deliver some vegetable dyes or extracts. Quinoa protein isolates have been scarcely applied in emulsion gel formulation although they seem to be a promising alternative as emulsion stabilizers. Quinoa protein isolates have a high protein content with a well-balanced amino acid profile and show good emulsifying and gelling capabilities. Unlike quinoa starch, quinoa protein isolates do not require any chemical modification before being used. The present article reviews the state of the art in food emulsion gels stabilized with vegetable proteins and highlights the potential uses of quinoa proteins in emulsion gel formulation.

Preparation and Characterization of a Novel Soy Protein Isolate-Sugar Beet Pectin Emulsion Gel and Its Application as a Multi-Phased Nutrient Carrier

Emulsion gel, a novel oral delivery carrier, provides the possibility to co-load hydrophilic and lipophilic nutrients simultaneously. In this study, duo-induction methods of laccase and glucono-δ-lactone (L&GDL) or laccase and transglutaminase (L&MTG) were used to prepare the soy protein isolate-sugar beet pectin (SPI-SBP) emulsion gel. The textural data of the emulsion gel was normalized to analyze the effect of different induction methods on the gel property of the SPI-SBP emulsion gels. The characterization studies showed the structure of L&MTG emulsion gel was denser with a lower swelling ratio and reduced degree of digestion, compared with L&GDL emulsion gel. Moreover, the release profiles of both β-carotene and riboflavin co-loaded in the SPI-SBP emulsion gels were correlated to the digestion patterns of the gel matrix; the controlled-release of encapsulated functional factors was regulated by a gel network induced by different induction methods, mainly due to the resulting porosity of the structure and swelling ratio during digestion. In conclusion, SPI-SBP emulsion gels have the capability of encapsulating multiple functional factors with different physicochemical properties.

Cocoa Coproducts-Based and Walnut Oil Gelled Emulsion as Animal Fat Replacer and Healthy Bioactive Source in Beef Burgers

The aim of this work was to evaluate the effects on the chemical, physic-chemical, technological, and sensory properties of beef burger when replacing different quantities of fat (50 and 100%) with different levels of oil-in-water-gelled emulsion elaborated with walnut oil and cocoa bean shell flour (GECW). The chemical composition of the samples was affected by the fat replacement. The reformulation increased the moisture and ash content while the fat and protein content decreased with respect to the control sample. The linolenic and linolenic acid content of the beef burgers increased as the GECW replacement was augmented. The polyunsaturated fatty/saturated fatty acid ratio increased in both raw and cooked burgers, whereas the atherogenicity index and thrombogenicity index were reduced in both raw and cooked burgers with respect to the control sample. The use of GECW as a fat replacer was found to be effective in improving the cooking loss. Similarly, there were positive effects on reductions in the diameter and the increases in the thickness of the beef burgers. Regarding lipid stability, in both the raw and cooked burgers, the reformulation increased the 2-thiobarbituric acid reactive substance (TBARs) values with respect to the control sample. In both types of reformulated burgers, three bound polyphenols (mainly catechin and epicatechin) and two free polyphenols were identified, as were methylxanthines theobromine and caffeine. The sensory properties for the control and partial pork backfat replacement treatments were similar, while the sample with the total pork backfat replacement treatment showed the lowest scores. The blend of cocoa bean shell flour and walnut oil could be used as new ingredients for the development of beef burgers with a healthier nutritional profile without demeriting their sensory or cooking characteristics and physic-chemical properties.

Future trends of processed meat products concerning perceived healthiness: A review

The 21st-century consumer is highly demanding when it comes to the health benefits of food and food products. In the pursuit of attracting these consumers and easing the rise in demand for high-quality meat products, the processed meat sector is intensely focused on developing reformulated, low-fat, healthy meat products. Meat and meat products are considered the primary sources of saturated fatty acids in the human diet. Therefore, these reformulation strategies aim to improve the fatty acid profile and reduce total fat and cholesterol, which can be achieved by replacing animal fat with plant-based oils; it could be performed as direct inclusion of these oils or pre-emulsified oils. However, emulsions offer a viable option for incorporating vegetable oils while avoiding the multiple issues of direct inclusion of these oils in meat products. Processed meat products are popular worldwide and showing a gradually increasing trend of consumption. Various types of plant-based oils have been studied as fat replacers in meat products. This review will focus on possible methods to reduce the saturated fatty acid content in meat products.

Effect of the Addition of Chia Seed Gel as Egg Replacer and Storage Time on the Quality of Pork Patties

Two types of patties were prepared: control and with chia seeds gel instead of beaten egg. The patties were cooked in the steam-convection oven, vacuum packed and stored at 4 °C. The pork patties with chia addition were characterized by similar water activity and pH values to the control samples. They showed lower values of the b* colour parameter as well as colour saturation (C*) and hue angle values (h°) on the cross-section and lower values of colour parameters L*, a* and b* and C* on the surface than the controls. The addition of chia seeds improved the texture parameters of the tested products. Pork patties with chia seeds were softer and showed better chewiness than the control samples. Chia slowed down oxidative changes in pork patties during storage. The use of 8.0% addition of chia seeds was only slightly noticeable in taste of the pork patties and these samples received similar overall quality scores as control samples.

Total and Partial Fat Replacement by Gelled Emulsion (Hemp Oil and Buckwheat Flour) and Its Impact on the Chemical, Technological and Sensory Properties of Frankfurters

A gelled emulsion (GE) prepared with hemp oil and buckwheat flour was used to replace pork back fat in frankfurters. Five different formulations were prepared: control (with 35% pork back fat—SC), and the following four to achieve 25%, 50%, 75%, and 100% pork back fat substitution by GE (S1, S2, S3, and S4, respectively). Nutritional, technological, and sensorial characteristics of frankfurters were evaluated. Sausages containing GE presented a lower total fat content with a higher amount of polyunsaturated fatty acids, increased omega 3 content, and reduced saturated fat by up to 55%. The incorporation of GE did not significantly modify technological properties such as emulsion stability or lipid oxidation in spite of using vegetable oils highly susceptible to oxidation. The reformulation of the frankfurters presented a greater effect on the texture and sensory properties when GE was used as total substitution for the pork back fat (S4). When GE was used only as partial substitution for the pork back fat, sausages similar to control frankfurter were obtained. So this study demonstrated that the use of GE could be a promising strategy in the reformulation of healthier meat products.

Assessment of Chemical, Physicochemical, and Lipid Stability Properties of Gelled Emulsions Elaborated with Different Oils Chia (Salvia hispanica L.) or Hemp (Cannabis sativa L.) and Pseudocereals

Gelled emulsion (GE) systems are one of the novel proposals for the reformulation of meat products with healthier profiles. The aims of this research were (i) to develop gelled emulsions using pseudocereal flours (amaranth, buckwheat, teff, and quinoa) and vegetable oils (chia oil, hemp oil, and their combination), (ii) to determine their chemical composition, physicochemical properties, and lipid stability, and (iii) to evaluate their stability during frozen storage. The results showed that GEs are technologically viable except for the sample elaborated with teff flour and a mix of oils. The lipid oxidation was not greater than 2.5 mg malonaldehyde/kg of sample for any of the samples analyzed. The physicochemical properties analyzed showed both the pH and color values of the GEs within the range of values obtained for the fat of animal origin. The texture properties were affected by the type of oil added; in general, the firmness and the work of shear increased with the addition of the mixture of both oils. The samples elaborated with buckwheat and chia oil and quinoa and chia oil had the highest emulsion stability values, which remained among the highest after freezing. The results showed that gelled emulsions, based on chia oil, hemp, and their mixture with pseudocereal flours, are a viable alternative as a possible substitute of saturated fat in the development of novel foods.

Structural and Technological Approach to Reveal the Role of the Lipid Phase in the Formation of Soy Emulsion Gels with Chia Oil

Considerable attention has been paid to emulsion gels (EGs) in recent years due to their interesting applications in food. The aim of this work is to shed light on the role played by chia oil in the technological and structural properties of EGs made from soy protein isolates (SPI) and alginate. Two systems were studied: oil-free SPI gels (SPI/G) and the corresponding SPI EGs (SPI/EG) that contain chia oil. The proximate composition, technological properties (syneresis, pH, color and texture) and structural properties using Raman spectroscopy were determined for SPI/G and SPI/EG. No noticeable (p > 0.05) syneresis was observed in either sample. The pH values were similar (p > 0.05) for SPI/G and SPI/EG, but their texture and color differed significantly depending on the presence of chia oil. SPI/EG featured significantly lower redness and more lightness and yellowness and exhibited greater puncture and gel strengths than SPI/G. Raman spectroscopy revealed significant changes in the protein secondary structure, i.e., higher (p < 0.05) α-helix and lower (p < 0.05) β-sheet, turn and unordered structures, after the incorporation of chia oil to form the corresponding SPI/EG. Apparently, there is a correlation between these structural changes and the textural modifications observed.

Cold-set or hot-set emulsion gels consisted of a healthy oil blend to replace beef fat in heat-treated fermented sausages

The current work aimed to investigate the utilization of gelled emulsion (GE) systems stabilized either with cold or hot gelation consisted of peanut and linseed oils as fat replacers in fermented beef sausages. The reformulation provided a healthier lipid profile, that led to decreasing total lipid content, cholesterol, and SFAs (from 46.6% to 23.5%) meanwhile increasing both MUFAs (from 47.3% to 51.0%) and PUFAs (from 4.7% to 25.4%) as well as improving nutritional ratios (ω-6/ω-3, PUFA/SFA, IA, and IT). Cold-set GE caused less significant changes in instrumental color and protected PUFAs compared with hot-set GE, whereas hot-set GE provided advantages over cold-set GE in terms of microstructure, purge loss, and sensory scores. Replacement of beef fat fully by a hot-set GE system instead of using a fat-GE mixture was effective in reducing oxidation. The results demonstrated that utilization of different GE systems can be an effective strategy to contribute to the development of lipid-modified fermented meat products.

Development of Meat Products with Healthier Lipid Content: Vibrational Spectroscopy

This review focuses on the importance of developing meat products with healthier lipid content and strategies such as the use of structured lipids to develop these enriched products. The review also conducts a critical analysis of the use of vibrational spectroscopy as a tool to further these developments. Meat and meat products are extensively recognized and consumed in the world. They are an important nutritional contribution in our diet. However, their consumption has also been associated with some negative consequences for health due to some of its components. There are new trends in the design of healthy meat products focusing mainly on improving their composition. From among the different strategies, improving lipid content is the one that has received the most attention. A novel development is the formation of lipid materials based on structured lipids such emulsion gels (EGs) or oil-bulking agents (OBAs) that offer attractive applications in the reformulation of health-enhanced meat products. A deeper interpretation is required of the complicated relationship between the structure of their components and their properties in order to obtain structured lipids and healthier meat products with improved lipid content and acceptable characteristics. To this end, vibrational spectroscopy techniques (Raman and infrared spectroscopy) have been demonstrated to be suitable in the elucidation of the structural characteristics of lipid materials based on structured lipids (EGs or OBAs) and the corresponding reformulated health-enhanced meat products into which these fat replacers have been incorporated. Future research on these structures and how they correlate to certain technological properties could help in selecting the best lipid material to achieve specific technological properties in healthier meat products with improved lipid content.

Recent Discoveries in the Field of Lipid Bio-Based Ingredients for Meat Processing

Current culture and pace of lifestyle, together with consumer demand for ready-to-eat foods, has influenced the food industry, particularly the meat sector. However, due to the important role that diet plays in human health, consumers demand safe and healthy food products. As a consequence, even foods that meet expectations for convenience and organoleptic properties must also meet expectations from a nutritional standpoint. One of the main nutritionally negative aspects of meat products is the content and composition of fat. In this sense, the meat industry has spent decades researching the best strategies for the reformulation of traditional products, without having a negative impact in technological processes or in the sensory acceptance of the final product. However, the enormous variety of meat products as well as industrial and culinary processes means that a single strategy cannot be established, despite the large volume of work carried out in this regard. Therefore, taking all the components of this complex situation into account and utilizing the large amount of scientific information that is available, this review aims to comprehensively analyze recent advances in the use of lipid bio-based materials to reformulate meat products, as well as their nutritional, technological, and sensorial implications.

Impact of Culinary Procedures on Nutritional and Technological Properties of Reduced-Fat Longanizas Formulated with Chia (Salvia hispanica L.) or Oat (Avena sativa L.) Emulsion Gel

This paper evaluates how grilling, a traditional culinary procedure for fresh meat products, affects the composition and technological properties of healthy longanizas formulated with chia (Salvia hispanica L.) (C-RF) and oat (Avena sativa L.) (O-RF) emulsion gels (EGs) as animal fat replacers. The use of EGs, regardless of whether they contain chia or oat, improved longaniza performance during cooking as they lost less (p < 0.05) water and fat. The composition of cooked sausages was affected by their formulation, particularly those with chia EG (C-RF) which featured the highest polyunsaturated fatty acid content, mainly due to the higher level of α-linolenic fatty acid (1.09 g/100 g of product). Chia and oat EGs in C-RF and O-RF allow longanizas to be labeled with nutritional and health claims under European law. In general, this culinary procedure increases (p < 0.05) the lightness, lipid oxidation and texture parameters of all samples.

Improved green biosynthesis of chitosan decorated Ag- and Co3O4-nanoparticles: A relationship between surface morphology, photocatalytic and biomedical applications

AgNPs@Chitosan and Co₃O₄-NPs@Chitosan were fabricated with Salvia hispanica. Results showed MZI values of 5 and 30 mm for Co₃O₄-NPs- and AgNPs@Chitosan against S. aureus, and 15 and 21 mm for Co₃O₄-NPs- and AgNPs@Chitosan against E. coli (24 h, 20 μg/mL), respectively. MTT assays showed up to 80% and 90%, 71% and 75%, and 91% and 94% mammalian cell viability for the green synthesized, chemically synthesized AgNPs and green synthesized AgNPs@Chitosan for HEK-293 and PC12 cells, respectively, and 70% and 71%, 59% and 62%, and 88% and 73% for the related Co₃O₄-NPs (24 h, 20 μg/mL). The photocatalytic activities showed dye degradation after 135 and 105 min for AgNPs@Chitosan and Co₃O₄-NPs@Chitosan, respectively. FESEM results showed differences in particle sizes (32 ± 3.0 nm for the AgNPs and 41 ± 3.0 nm for the Co₃O₄NPs) but AFM results showed lower roughness of the AgNPs@Chitosan (7.639 ± 0.85 nm) compared to Co₃O₄NPs@Chitosan (9.218 ± 0.93 nm), which resulted in potential biomedical applications.

The Effect of Emulsifying Protein and Addition of Condensed Tannins on n-3 PUFA Enriched Emulsions for Functional Foods

This paper examines the effect of the type of the emulsifying protein (EP) (sodium caseinate (SC) and whey protein isolate (WPI)) on both oil-in-water liquid-like emulsions (Es) and the corresponding cold gelled emulsions (GEs), and also the effect of addition of carob extract rich in condensed tannins (T). The systems, intended as functional food ingredients, were studied in various different respects, including rheological behaviour, in vitro gastrointestinal digestion with determination of the release of non-extractable proanthocyanidins (NEPA) from T, antioxidant activity and lipolysis. EP significantly affects the rheological behaviour of both Es and GEs. T incorporation produced a structural reinforcement of GEs, especially in the case of SC. The digests from Es displayed a higher antioxidant activity than those from GEs. T lipase inhibition was observed only in the formulations with WPI. Our results highlight the importance, in the design of functional foods, of analyzing different variables when incorporating a bioactive compound into a food or emulsion in order to select the better combination for the desired objective, owing to the complex interplay of the various components.