Emulsion-filled gel is a sort of gel system that traps oil droplets as a filler and contains a wide range of semi-solid to solid food products. It can also be utilized as a dual system to distribute and control the release of both lipophilic and hydrophilic bioactive and micronutrient substances. The main polymers involved in gel formation in food products are proteins and polysaccharides. Using molecular interactions between biopolymers, a wide range of rheological and physicochemical properties of gels can be methodically created. As a result, the interaction between proteins and polysaccharides has received a lot of attention in order to generate novel products. Because of their functional qualities and high nutritional value, whey proteins are frequently used in the food industry. As a result, mixed gels based on whey protein have gained a lot of attention. k-Carrageenan is commonly utilized in the food industry as a gelling and firming agent. Because k-Carrageenan, like whey protein isolate, can form a gel independently, its interaction with whey protein isolate in emulsion gel systems appears appealing. Therefore, in this study, the effect of k-Carrageenan gum (0.0, 0.1, 0.3, 0.5, and 0.7%) on the textural (uniaxial compression test), rheological (steady shear, strain sweep, and frequency sweep tests), and water holding capacity of cold-set emulsion-filled gel based on whey protein isolate was investigated.

 Whey protein isolate (WPI) (98.9% protein, dry basis) was given as a gift by Agropur Ingredients Co. (Le Sueur, Minnesota, USA). -Carrageenan and CaCl2 ( : 147.01 gr/mol) were purchased from Sigma Aldrich Co. (USA) and Merck Co. (Darmstadt, Germany), respectively. Sunflower oil was supplied from local supermarket. Stock dispersions of WPI and -Carrageenan were prepared by dissolving sufficient amounts of their powders in deionized water. To prepare uniform oil in water emulsion, sunflower oil was added to the WPI dispersion and the obtained mixture homogenized first using a laboratory rotor-stator homogenizer (15000 rpm, 3 min), then by an ultrasonic homogenizer (20 kHz, 5 min). The prepared emulsion and -Carrageenan dispersions were poured into Schott bottles and heated in a water bath (90 °C, 40 min). WPI emulsion and AG dispersion were mixed in a cylindrical container on a stirring plate at a speed of 600 rpm for 6-8 min to obtain a homogeneous mixture. After decreasing the temperature to 60 °C for the ion-induced gelation, the mixtures were charged with CaCl2 (10 mM). The prepared samples were incubated in a refrigerator overnight to stabilize the 3D network. The final mixed EFG samples contained 5.5% WPI, 20% oil, and 0, 0.1, 0.3, 0.5, and 0.7% (w/w) of k-carrageenan. The tests performed on emulsion-filled gel samples were: 1) steady shear (0.01-10 s-1), 2) strain sweep (strain: 0.1-1000%, frequency: 1 Hz), 3) frequency sweep (frequency: 0.1-100 Hz, strain: 0.5%), 4) uniaxial compression (target strain: 80%, deformation speed:1 mm/s), and 5) water holding capacity (by utilizing a microcentrifuge, 600×g for 10 min).

 According to the results of steady shear test, all samples had a shear thinning behavior, and based on the power-law model, this behavior was intensified in the presence of k-Carrageenan; and with increasing the gum concentration from 0 to 0.7%, the consistency coefficient increased from 339.9 to 545.7 Pa.s. In the strain sweep test, with the increase in the gum concentration, the values of the elastic and viscous modulus in the linear region and the modulus at the crossover point increased, and tan dLVE decreased from 0.17 to 0.13, which indicated an increase in the strength of the emulsion gel network structure. Based on the frequency sweep test, with the increase in k-Carrageenan concentration, the parameters  and , network strength and network expansion increased from 5311.8 Pa, 939.9 Pa, 1.5380 Pa.s1/z and 10.05 in the control sample to 25080 Pa, 3574.9 Pa, 16097.7 Pa.s1/z and 16.41 in the sample containing 0.7% k-Carrageenan, respectively. Moreover, the frequency dependency of elastic modulus decreased from 0.095 in the control sample to 0.050 in the 0.7% k-Carrageenan contained sample. According to the large deformation test, in general, in the composite emulsion-filled gels, the values of apparent modulus of elasticity and fracture stress were higher and fracture strain and fracture energy were lower than in the control sample. Also, the results showed that different k-Carrageenan concentrations had no significant effect on the water holding capacity.

The obtained results showed that k-Carrageenan had considerable influence on the rheo-mechanical features of cold-set emulsion-filled gels based on whey protein which can add to the knowledge base for the production of new functional foods.

Looking for the development of new food ingredients, the Box-Behnken design was employed to determine the effect of two different oleogels, elaborated with a celluloses mixture or with candelilla wax, as oil fraction, on the textural properties of emulsion-filled gels with egg white as emulsify/gelling agent, at different ionic strength conditions. Compression test parameters were determined on both samples (force, work, and modulus) to analyze the effect of the variables on texture. Emulsion-filled gels with candelilla wax oleogel resulted in firmer and more difficult to compress, as compared to cellulose oleogel, with a less hard and softer texture. The increase in protein concentration resulted in a stiffer texture, but when the oil fraction (oleogel proportion) increased, the emulsion-filled gel texture turned more squishable. No major effect was observed by the employed ionic strength conditions. The model predictions for textural parameters in both samples were closely correlated to the experimental results obtained. The use of different ingredients that can be employed as oil fractions with different textures that can be manipulated, distinct oleogel formulations -as the type of organogelator agent, a type of edible oil- allows the designing of textural and thermal properties of emulsion-filled gels, with great potential as fat replacers in processed foods.

This study was conducted to evaluate the influence of chitosan Nano-gel/emulsion coating functionalized by Ziziphora clinopodioides essential oil (ZCEO) and nisin on growth inhibition of Escherichia coli O157: H7 inoculated in beef samples during 16 days in cold storage condition (4˚C).  Beef sample was divided into six groups after inoculation of E. coli O157:H7. Treatments including control (no coating), chitosan 2%, sonicated chitosan 2%, Nano-emulsion of chitosan coating containing ZCEO (0.5%), Nano-gel of chitosan coating containing nisin (200 IU/g), Nano-emulsion of chitosan coating containingZCEO (0.5%) and nisin (200 IU/g) were stored at refrigeration temperature and bacterial count were performed on days: 0, 1, 2, 4, 8, 12 and 16. Data were analyzed using repeated measure ANOVA and Bonferroni post hoc tests. Result indicated a significant reduction in E. coli O157:H7 count in all treatments when compared to control group and the highest inhibitory activity was observed in chitosan Nano-emulsion coating containing ZCEO (0.5%) and nisin (200 IU/g).  Accordingly, it is suggested that chitosan Nano-emulsion coating with ZCEO and nisinpractically be applied in beef to increase its safety against pathogenic bacteria especially E. coli O157: H7.

Fats have a special place in human nutrition and their main role is supplying energy for the body. But scientific findings approve an association between high fat intake and an increment risk of some diseases, such as atherosclerosis, heart disease, and …. Demand for low-fat foods has increased dramatically as people become more aware of fat consumption side effects. However, due to the multiple role of fats in food products, eliminating or decreasing fat lead to poor quality of products. Therefore, it is necessary to use a combination of fat substitutes to maintain the rheological, texture and sensory properties of the low fat food products. The use of emulsion gel structures are new methods for the production of low-fat product that has been studied in this investigation. The Pickering emulsion was used to produce the emulsion. In this method, instead of using surface-active agents, solid particles are used to stabilize the emulsion. The aim of this study was to prepare Pickering Emulsion from Isolated Soybean protein (ISP) and Basil Seed Gum (ISP-BSG) Complex. Finally, emulsion gel systems were applied as fat substitutes in cream.

Basil seeds were purchased from Mashhad market. Isolated soy protein was purchased from Shandong Yuxin Bio-Tech Co. (China). Sodium azide was purchased from Applichem Inc. (Dramstadt, Germany). Sodium dodecyl sulphate (SDS) was obtained from Merck, Germany.  Pickering (solid particles) of soy protein isolate (SPI) and SPI-basil seed gum (ISP-BSG) complex used as emulsifier for stabilization of cold emulsion. ISP-BSG particles were prepared with different mass ratios of ISP: BSG, 1: 0, 1: 1, 2: 1 and 3: 1 and named 1S: 0B, 1S: 1B, 2S: 1B and 3S: 1B, respectively. These solid particles were used as Pickering for emulsion preparation. Cold Emulsion was prepared by adding calcium chloride. The oil leakage, oil leakage after thermal treatments, microscopic structure, textural properties and viscoelastic properties of emulsion gel were studied. Then, the best structures used as a fat substitute in cream (5, 10 and 15%).

Investigation of emulsion gel properties showed that coating the surface of emulsion droplets with solid nanoparticles formed a rigid shell that acted as a barrier against the deformation and transfer of materials from the interfacial surface. The use of ISP-BSG nanoparticles as picking particles caused more homogeneity and stiffness in emulsion gel structure. The rate of water loss in reduced fat cream was in the range of 1-2% by using the emulsion-gel system, which indicates the effectiveness of these systems in reducing dehydration in cream. The increasing replacement percentages led to increase water loss (p <0.05). However, emulsion type had no significant effect on water loss content (p> 0.05). According to the results, ISP-BSG nanoparticles impart high potential to stabilize emulsion with small oil droplets. Based on the results of the sensory test, it was found that the characteristics of the cream samples depended more on the replacement rate than the type of system used as an alternative. The presence of a fat replacement system maintained the desired quality in low-fat cream samples. Most of the samples scored higher than 3, which indicate the high acceptance of low-fat samples.

Proteins and polysaccharides have an important influence on the structure, texture and stability of food systems and their mixed gel can be used as a model for soft solid products. Production of cold set gelation based on protein is a novel food processing method that would positively affect the physical properties of the product. In this research, the mixed gels of whey protein concentrate (WPC) and Persian gum (PG) were produced using the cold set gelation at neutral pH (induced by CaCl2) and acidic pH (by Glucono delta- lactone addition). The dynamic rheological properties, syneresis, and the microstructure of gels were investigated by scanning electron microscope (SEM). The strong electrostatic bonding at the acidic condition resulted in the lower required WPC concentration (4% wt.) comparing to the neutral gelation condition (7% wt.). Both cold set methods required protein concentrations below the critical value of whey protein at the heat-set gel method (10-12% wt.). The results showed more PG concentration at the neutral pH, the higher viscoelastic moduli values of the mixed protein gels. However, the effect of gum on rheological moduli changes for the acidic gels, were very small. Increasing the Persian gum concentration significantly decreased the syneresis in the both gel formation methods. The results of this research reveals the potential of cold set gelation of WPC- PG mixed biopolymers in the production of a range of different gels.

: Nowadays, the tendency to use low-fat food is so obvious among consumers. Removing food fat leads to undesirable sensory and performance characteristics. Thus, different compounds have been introduced as fat replacer in order to produce low-fat food products. The aim of this study was to reduce the used fat in sausage production by using emulsion filled gel. The fat of frankfurter sausage formulation was substituted with emulsion filled gel as fat replacer at the rates of 0, 50 and 100% and the properties of produced low-fat sausage were evaluated in terms of chemical compounds, pH, textural properties, color, porosity, cooking loss, water holding capacity and sensory characteristics. The results showed that the sausage containing emulsion filled gel had higher moisture, ash, pH, water holding capacity and porosity. As by increasing the substitution percent, these factors were also increased. On the other hand, fat content, cooking loss, cutting force and textural properties (hardness, cohesiveness, gumminess, and chewiness) except springiness of products were decreased. Emulsion filled gel darkened the sausages, and by increasing the substitution percent, L (brightness) and a (redness) were decreased and b (yellowness) was increased. Sensory evaluation results showed that using emulsion filled gel in low-fat sausage production could not cause meaningful effect on the consumers’ general accept of this product. So, it is possible to produce a low-fat product with good qualitative and nutritional properties by substitution of the used oil in sausage production with emulsion filled gel.

This study evaluated the impact of agar gum (AG) (0-0.7% w/w) on the textural, rheological, and held water characteristics of cold-set whey protein isolate emulsion filled gel (EFG). Steady shear results showed that EFGs had a shear-thinning flow behavior, and with increasing AG concentration, the consistency </em>coefficient increased from 339.12 Pa.sn</sup> (no AG) to 951.46 Pa.sn</sup> (0.7% AG). The amplitude sweep assay illustrated that the AG level had a meaningful effect on the rheological parameters so that GʹLVE</sub></em>, GʹʹLVE</sub></em>, Gf</sub></em> and tF</sub> increased, and Tan dLVE</sub></em> decreased with an increase in the AG level. Based on the frequency sweep test, adding AG significantly enhanced the magnitudes of kʹ and kʹʹ, so that their values increased from 5311.80 and 939.90 Pa in the control to 25080.60 and 3574.90 Pa in the 0.7% AG-contained sample, respectively. Also, the parameters of the strength of the network (5380.10-25344.30 Pa.s1/z</sup>), the network extension (10.05-15.59) and the extent of departure from the Cox-Merz </em>rule (3476.80 to 21509.44 Pa) increased directly as a result of the rise in AG content. In the composite EFG with 0.7% AG, the highest initial tangent modulus and fracture stress were recorded, which showed lower fracture strain and equal fracture energy in comparison to the control sample. Research results also showed that the held water decreased meaningfully at a high concentration of AG. These results add to the knowledge of the protein-polysaccharide interactions that can be helpful in the production of new functional foods.

Gellan gum was exploited to modulate the stability of sesame oil-in-water emulsion and fabricated stable droplets with mean size of ̴ 9 μm till 30 days, then gelified by CaCl2 solution with final concentration of 55mM or 1% GDL. Enrichment with CaCl2 increased the amount of compact structures in gels in conjunction with decreasing WHC values and textural features modification. Gellan bundles as visualised by microscopic images conferred a remarkable influence to gel samples; enrichment with GDL or control gels increased the WHC value and formed less coarse networks. Based on Fourier transform infrared (FTIR) spectroscopy it was suggested that was no major changes in the functional groups of different gel samples, also according to the results of XRD analysis all the emulsion gels had an amorphous nature. The results indicated close relationships between physicochemical properties and microstructures of gellan-stabilized emulsion gels and would be of vital importance for extending the present knowledge about the preparation and properties of emulsion gels from gellan gum.

Many food products are comprised of an emulsion gel structure in which emulsion droplets are dispersed within a gel network. Formation of a stable emulsion which is later turned into a gel using processing techniques including heating, acidification or enzyme assisted-clotting is a crucial stage in the production of an emulsion-gel system. In the present study the influence of various concentrations of whey protein concentrate (3-8% w/w) and water soluble fraction of Persian gum (0.3-0.6% w/w) on the quality attributes of oil-in-water emulsion prior and after heat treatment (at 90 oC for 30 min) was evaluated. To this end, changes in the zeta potential, size of droplets, rheological behaviour of emulsions and also their microstructure were investigated. The results showed that increasing the concentration of whey protein concentrate in the system reduced the size of the emulsion droplets. On the other hand, the addition of 0.6% soluble fraction of Persian gum led to larger droplets. More over, heating emulsion samples resulted in a rise in the size of droplets and broadened their size distribution curves. However, Persian gum at lower level (0.3%) was found to considerably increase the stability of emulsion against heat. The viscosity of emulsion was shown to be greatly dependent on the soluble fraction of Persian gum concentration and dramatically increased upon heating which was attributed to depletion flocculation and protein aggregation. In addition, all samples exhibited Newotonian behaviour before and after heat treatment except at higher proportions of whey protein concentrate and Persian gum, which changed to shear thinning following heating. These findings confirm the capability of Persian gum for production of heat stable emulsions which may find various applications in food formulation such as Emulsion-gels.

The current research was conducted to produce a gel emulsion with reduced saturated and Trans fatty acids that can be used as shortening. Hydrocolloids of guar gum, κ-carrageenan, CMC, and maltodextrin were used to prepare gel emulsion. For emulsion stability, PGPR (1%) was used as an emulsifier. In the first phase of the research, for the production of gel emulsion using guar gum from 0 to 0.25%, κ-carrageenan from 0 to 2%, CMC from 0 to 3%, and maltodextrin from 0 to 20%, different formulations were determined by Design Expert software and by Response surface method and optimal design, and samples formulations were produced. Sensory and hardness evaluation tests were performed and regression models for predicting hardness (sensory) responses, overall acceptance, and hardness were presented and the optimal formulation was determined. In the second phase of the research, the optimal formulation of gel emulsion at the levels of 25, 50, 75, and 100% was used to produce biscuits, and the physicochemical, sensory, and peroxide value were investigated. The results showed that by replacing 50% of shortening with biscuit gel emulsion with less amount of fat and saturated fatty acid and without Trans and in terms of physicochemical and sensory properties, it is obtained similar to the sample containing shortening.