فهرست مطالب رسول کد خدایی

Nowadays, with the development of technology, following an appropriate diet is of great importance, and different people go on various diets. Moreover, some food intolerance cause people to change their diets inevitably, with celiac disease being one of them. In celiac, which is an autoimmune and hereditary disease, the mucosal mem-brane of the pa-tient small intestine is damaged and inflamed after the consumption of gluten-containing cereal-based products. Accordingly, Rice flour is typically used in the production of gluten-free cake, and given the qualitative defects of gluten-free products, gluten substitutes should be employed. Application of Pickering emulsion (PE) is a way of enhancing the properties viscoelastic of cake. Nowadays, the research about the use of emulsion in the structure of gluten-free products has been expanded to improve its quality features. According to this, one of the practical applications gluten-free food products are important for individuals with celiac disease or gluten-related disorders since they need to follow a strict gluten-free diet. This study provides information on a Pickering emulsion stabilized by soy protein nanoparticles use to boost the physical properties of gluten-free cake batter. Results showed that use of these additives improved the techno-functional properties of the gluten-free cake batter. Therefore, the findings of this study can be use-ful for the production of functional free-gluten food products with health-promoting at-tributes. The aim of this research was to use Pickering emulsion (PE) stabilized by soy protein nanoparticles and xanthan gum in gluten-free cake dough based on Rice flour and monitor its quality indicators during shelf life. Considering the studies conducted so far, PE based on plant proteins like soy protein and microbial polysaccharides like xanthan, has not ever been reported in the preparation of gluten-free cake. Therefore, the purpose of this research is to stabilize PE by soy protein nanoparticles (SPNs), as well as investi-gating its effects on gluten-free rice flour-based cake and evaluation of its quality indica-tors during shelf life.

In this study, Pickering emulsion was prepared from soy protein nanoparticles and xanthan solution 0.1% (w/v). For this purpose, sunflower oil (20%) was gently added to the mixture of xanthan solution (20%) and SPNs (60%), which was sub-sequently agitated using a homogenizer at 11000 rpm. Next, the intrinsic properties of emulsion such as hydrodynamic diameter, polydispersity index (PDI) zeta potential, and creaming index of the SPNs and the PE were measured. Furthermore, the emulsifying activity (EA) test was performed according to the method presented by Dalev & Sime-onova (1995) with slight changes. Finally, the qualitative and viscoelastic properties of gluten-free cake-containing emulsion were investigated in comparison with the control sample during shelf life.

The results of this research showed that the presence of soy pro-tein nanoparticles along with xanthan gum caused stability, proper dispersion index, ho-mogeneity of particles, and determining the electrical state of the surface of particles in PE. In fact, the prepared PE had an acceptable dispersity, because the lower the PDI is, the more suitable the dispersity is, and the more homogenous the particles are. The zeta potentials of the SPNs and the PE were equal to -13.166 and -30.696 mV, respectively. The high zeta potential of colloidal particles causes an increase in electrostatic repulsive forces between them, thus raising the system physical stability at pH values above its isoe-lectric point. On the other hand, the emulsion prepared using the SPNs and the xanthan solution showed a higher zeta potential. Generally, xanthan solution is negatively charged at neutral pH, due to the occurrence of acidic groups in the structure of this gum. The presence of negative charge in both the SPNs and the gum elevated the zeta potential of the emulsion. The ability of the emulsion to resist the changes during three weeks showed insignificant phase separation and also with 78% emulsion activity. In addition, the pres-ence of PE (20 mL/100g rice flour) in the formulation of gluten-free cake dough im-proved the viscoelastic properties and quality of the final product during the shelf life of one week. In fact, considering the capability and usage of these emulsions in the food industry, especially the bakery industry, it improved the quality characteristics of cake products for the consumer, such as the specific volume and porosity of the cake, its tex-ture strength, and its shelf life. Pickering emulsion increased the moisture content in the cake, which had a positive effect on the hardness of the sample. Whereas, the volume and porosity decreased in the cake containing Pickering emulsion. On the other hand, the col-or of the sample was better maintained over time by adding emulsion during shelf life.

Based on the results of this research, SPNs improved the PE stability. Fur-thermore, xanthan gum inhibited the aggregation of the oil droplets by increasing the PE consistency and forming a network in the emulsion. The presence of PE in the gluten-free cake batter formulation caused a relative decrease in volume and porosity compared to the control sample by creating a coherent and uniform structure. By maintaining more moisture during the storage period, PE had much better viscoelastic and color characteris-tics compared to the control sample.

In the present study, hydrogel emulsion particles made by emulsion templating method were used in order to encapsulate a-tocopherol. An oil-in-water-in-oil emulsion was used as mold to make microgel particles. The aim of this study was to investigate the effect of partial replacement of whey protein with iota-carrageenan (0, 0.2 and 0.4 wt%) on emulsion properties, hydrogel particles and release of a-tocopherol. The results showed that the introduction of iota-carrageenan in the formulation increased the apparent viscosity of the simple emulsions, droplet size increased from 2.69 μm in emulsions containing whey protein alone to 2.95 and 2.71 μm in emulsions containing 0.2 and 0.4 of iota-carrageenan. Replacing 0.2 and 0.4% of iota-carrageenan reduced the zeta potential from -43.93 mV to -46.56 and -46.68 mV, respectively. The introduction of iota-carrageenan in the formulation also reduced the particle size and reduced the encapsulation efficiency of a-tocopherol in hydrogel emulsion particles. Addition of iota-carrageenan to the formulation of hydrogel particles reduces the release rate of a-tocopherol in simulated gastric fluid from 30.36% in particles containing whey protein alone to 28.90 and 28.22% in particles containing 0.2 and 0.4% of iota-carrageenan, respectively. The results of this study showed that replacing part of the whey protein with iota-carrageenan improved the release and delivery of the lipophilic bioactive compound to the intestine in hydrogel emulsion particles.

Solid lipid nanoparticles (SLN) are one of the appropriate delivery systems which attract enormous interest for encapsulating bioactive componds in recent years. One of the important physicochemical properties of SLNs is particle size that is influenced by formulation and production process parameters. Inappropriate conditions of the nanaocarrier production process in the pre and main emulsion steps cause unsuitable paricle size as well as unstable emulsion and gel formation. Therefore, in this research production process of SLN was investigated and optimized by hot homogenization method and with two lipids of Compritol and Precirol separately. Hence, homogenization time in preparation of pre emulsion and amplitude and time of ultrasonication in final emulsion production was studied to obtained the smallest particle size. In pre emulsion step, the smallest particle size for Compritol SLN (619±4 nm) and Precirol SLN (373±3 nm) obtained in 180 second mixing by ultra-turax in 16000 (rpm). In final emulsion, 40% amplitude and 3 minutes caused to attained smallest particle size in Compritol SLN (397±5 nm) and Precirol SLN (259±2 nm). Then polydispersity index (PDI), zeta potential and visual observation of nanocarriers with optimized particle size were examined. The results showed that Precirol SLN had higher zata potential (-12.3±0.6 mV) than Compritol SLN (-8.97±0.17mV) but PDI of two nanocarriers was not significantly different. Visual observation of both nanocarriers at the storage time showed no instability.

According to the high tomato loss in Iran, the aim of the present study was to introduce Iranian endemic gums including tragacanth, locust bean and Alyssum homolocarpum seed gums for coating this fruit and also to investigate and compare their functional properties. The results showed that the solution of Alyssum homolocarpum seed gum had the highest wettability (-22.92 mN/m) on the fruits surface following by tragacanth gum (-43.23 mN/m) and locust bean gum (-22.92 mN/m). Moreover, the tragacanth and Alyssum homolocarpum seed gums showed the highest and the lowest apparent viscosities respectively. Investigating the physical features of the films revealed that tragacanth gum and locust bean gum had the ability to form transparent and flexible film; while, Alyssum homolocarpum seed gum film was more opaque and had a greenish hue with less flexibility. The water vapor permeability of tragacanth and locust bean gum films was significantly higher than that of Alyssum homolocarpum seed gum film (P<0.05). According to the results, it can be concluded that although Alyssum homolocarpum seed gum film had higher wettability on the surface of tomato, locust bean gum and tragacanth gum were more appropriate choices for tomato coating due to the higher transparency, apparent viscosity, water vapour inhibition and solubility in water.

Due to its distinct color, flavor and beneficial compound, the Saffron plant is extensively used in pharmaceutical and food industries, but because of its sensitive nature, its active compounds are lost in adverse environmental conditions. In this research, the preparation of water-in-oil nanoemulsion containing saffron extract was studied as an effective method for maintaining active compounds of saffron. For this purpose, nanoemulsions were synthesized by using span 80 and tween 80 as emulsifiers in three levels of 10, 12.5 and 15 percent, using ultrasound. The amount of aqueous phase (saffron extract with 12% dry matter) was 15% (wt) in all formulations and n-decan used on three levels: 70, 72.5 and 75% as oil phase. Particle size, polydispersity index and stability of each formulation at light conditions during 28 days after production were evaluated. The results showed the particle size and polydispersity index in the emulsion containing 15% emulsifier was less than the other emulsions and did not change in terms of physical stability.

In this study, a double emulsion system was developed based on an optimized initial simple emulsion with the view to increase the stability of effective saffron compounds (crocin, picrocrocin and safranal). To this end the effect of various concentrations of surfactant (10, 12.5 and 15%) and different types of carbohysrates (sucrose, sorbitol, and dextran) on the stability of simple emulsion was investigated. The principal component analysis method was used to identify the relationships between the quantitative changes of the active components and quality attributes of the emulsion. Based on the results, day 7 was recognized as a critical point on which dramatic changes in the quality attributes of the emulsion coincided with the loss of saffron active compounds. In other words, physical changes in the stability of emulshion correlated well with the destruction trend of active compounds, although picrocrocin changes were found to be of independents. Also, it was revealed that the incorporation of 1% w/w sorbitol into the aqueous extract of saffron significantly decreased the loss rate of saffron active compounds in the emulsion. In addition, the double emulsion increased the half-life of saffron active compounds during a 14 day storage period. The results showed that double emulsion system was a suitable method for saffron extract, but the qualitative properties of initial emulsion also had a great influence on their stability. Multivariate analysis methods can also be used to clarify the relationships between the qualitative properties of the emulsion and the active compounds entrapped within it.

Gum tragacanth (GT) is one of the natural secreted hydrocolloids which have many applications in food and pharmaceutical industries. Unfortunately, there is limited scientific information about the electrostatic interactions of gum tragacanth with proteins, especially the proteins that have been unfolded by physical approaches. In this regard, the main objective of this study is investigation the effect of thermal processing on the whey protein isolate (WPI) properties and their complexation with gum tragacanth. The influence ofheating time (0, 5, 10, 15, 20, 25, 30 and 35 min at 80C) on the turbidity of WPI, alone and in the mixture with GT (r = 0.1, pH 4.0 and Cp 0.1 w/w) was surveyed. Then the flow behaviour and viscosity of gum tragacanth-WPI mixture solution in the shear rate of 0-100 S-1 (pH 4.0) was compared with the individual solutions of gum and protein. Since the maximum turbidity was observed in the range of 15-35°C, the impact of heating time at three levels (15, 25 and 35 min) and biopolymer mixing ratio at six levels (2:1, 1:1, 1:2, 1:5, 1:10 and 1:20) on the protein and carbohydrate compositions of precipitation and supernatant were investigated by lowry and phenol-sulphuric acid experiments, repectively. Turbidity of protein solutions were significantly changed with rising the heating time such that the maximum turbidity achieved after 25 min thermal processing. While these solutions were unstable due to protein-protein interaction and formation of protein aggregates, GT addition leads to meaningful changes in the stability of protein solutions which was as a result of protein-polysaccharied interactions. Similar to protein solutions, the maximum turbidity of the complexes was achieved after 25min thermal processing. The rheological measurements showed that the mixture solution has pseudoplastic behavior with a large hysteresis loop as well as the higher viscosity rather than the blank solutions, all of which indicate the formation of electrostatic interactions between protein and polysaccharide and formation of complexes.By calculation of protein and polysaccharide in the supernatant and precipitation, the least ratio of Pr:PS was observed for the 25-min-treated WPI. Furthermore, the ratio of Pr:PS in the precipitation was increased significantly as Pr:PSratio was increased in the mixture. Addition ofgum tragacanth to the whey protein isolate will leads to a significant stability in the solution. Due to unfolding of WPI, using thermal processing on the whey protein isloate solution results in the meaningful increasing in the turbidity of protein solution and the efficiency of GT-WPI complex formation.

Gum tragacanth (GT) does not readily form a true gel using conventional methodsowing to its specificstructure and thus chemical cross-linkers e.g. glutaraldehydehave often to be used.The residue of these chemicals and their derivatives have to be removed/extracted from the final gel not only due to their toxicity but also because of the possible interactions they may have with the bioactive compounds carried and/or delivered by the network. These drawbacks limit their application if food industry and tissue engineering. This review article deals with the structural characteristics and physicochemical properties of GT as one of the most widely used polysaccharide in food and pharmaceutical industry and discusses the various methods commonly employed for gelation including physical and chemical approaches. Moreover, a novel green approach which is based on the authors' recent studies as well as other safe and cross-linker free techniques such as irradiation that can be used for making GT gel will be introduced.

Iran, with more than two hundred thousand tons of sweet cherry production in a year, is one the three top producers of this commodity in the world. Although the cherry produced in Iran is of high quality, but a large amount of this product is wasted due to its high perishability and sensitivity. Therefore, the aim of the present research was to increase the shelf life of the sweet cherry (cv. Siah Mashhad) with the aid of the coating method. In this regard an edible coating based on locust bean gum was used to coat sweet cherries and the properties of the coated samples including their weight loss, acidity, pH, soluble solid, maturity index, firmness and color changes were monitored during 30 days at 4℃ and 15% relative humidity. Also the results were compared to those of the non-coated samples. According to the results during the storage period, the samples acidity and pH did not change significantly, but the weight loss, soluble solid and the maturity index of the cherries increased and their firmness decreased significantly (p<0.05). Color measurements showed that the L and a color parameters of the cherries and their stems decreased significantly during the storage period. A comparison between the coated and the non-coated samples showed that the coating used in this study significantly decreased the rate of changes in weight loss, soluble solid, maturity index, firmness and color. Therefore, the coating used in this study could be recognized as an effective material for increasing the shelf life of sweet cherry.

Carrageenans are a family of linear sulphated polysaccharides that have broad applications in the food sector and pharmaceutical industry. Based on the degree of sulphation (polyelectrolytes) in carrageenan, only Kappa and Iota carrageenan have the ability of forming a gel structure. The mechanical characteristics of their gels, however, is affected by the polyelectrolyte nature of their chains. Iota and kappa carrageenan provide elastic soft gel and brittle rigid one, respectively, in the presence of calcium and potassium salts as their favored ions; while their mixture provides a broad range of structures with unique textures. The combination of these two biopolymers would result in a broad range of unique textures for different applications. The aim of this Study was to determine the effect of chain association (molecular association) on the textural properties of kappa- Iota carrageenan mixed gel. The texture of gels was investigated through the puncture test to determine some properties including hardness, toughness, deformability modulus, resilience, yield point, and proportional limit. In addition, the stress relaxation test was applied to evaluate the effect of the chain association formed in the network on the stress decay parameter.
A commercial Kappa-carrageenan, Genugel type, and Iota- carrageenan, Genuvisco type without further purification were purchased from CP Kelco (Lille Skensved, Denmark). Potassium chloride (KCl) and calcium chloride dihydrate (CaCl2•2H2O) of analytical grade were purchased from Merck company. The mixtures were prepared in 2:1, 1.5:1.5 and 1:2 ratios and the final concentration of 0.3% w/w biopolymer. Both calcium and potassium chloride were added using a strategy adopted for each salt for keeping the same ionic strength of molar concentrations of 2.5, 5 and 7 mmol in the biopolymer dispersions. The mechanical properties of the gels were investigated using an XT. T2 Texture Analyzer (Stable Micro Systems, Surrey, UK). Peltier system was utilized in adjusting the temperature at 4oC. The samples were equilibrated at least 10 min before performing the test. Crosshead speed was adjusted at 10 mm/min to a 12 mm depth (50% from total length) from the surface of the samples using a 1 mm diameter cylindrical aluminum probe for puncture test and a 2 mm/min crosshead speed using a 75 mm diameter cylindrical aluminum probe in 20% strain was applied for the stress relaxation test during 60 second time interval. Pleg and Normand equation was applied for the determination of viscoelastic properties of samples.
Result & Among different methods in the mechanical study of biopolymer gel, the puncture test is a promising method due to its ability in applying normal and shear forces on and into the structure simultaneously. In the presence of calcium and Potassium salts, the same pattern in the puncture curve was observed with increasing of ionic strength in the medium. According to the chain association formed as a result of the ion type, the pattern shows a transient from the elastic to the plastic deformation with different limits. The hardness as a parameter that indicates a composite biopolymer network resistance to break up, showed a higher value for the network containing Potassium salt. It would be due to the formed intra chain association in the system. For calcium salt, the results revealed a small variation in the hardness parameter with increasing the ionic strength. The area under the curve of stress- time is defined as toughness of the structure. The network formed by the intra chain association in the presence of potassium shows a free chain movement which leads to a plastic deformation with absorbing more energy before breaking the gel structure. Concerning the type of chain association, higher values of deformability modulus in the gels containing calcium salt is reasonable. Resilience, yield point and proportional limit are the characters related to the network homogeneity and bond stretching. In the networks with no depletion region, applying an external force to the body would lead to a uniform change in the initial state of the structure. In this kind of netwoks, the force distributed in the whole structure uniformly and local stress is not created. The chain movement as a result of bond stretching, causes a back stress occurance in the structure. When the primary stress is eliminated, the accumulated back stress will make the polymer to return to its original form. Interweaving the network by the intra chain association will result in a homogenous network formation and subsequently, to a higher parameter values in the linear region. The large deformation measurements were performed through the stress relaxation test to study the response of the structure during the interval times and to evaluate the viscoelastic properties of biopolymers network. Longer stress decay time was observed for the network developed in the presence of Potassium salt. The result obtained by studying the stress decay rate was in agreement with the properties observed from the evaluation of the linear region in the puncture test. On the other hand, the deformability modulus values conform to the result from hypothetical asymptotic level of the normalized relaxation parameter.

Carrageenans are a family of linear sulphated polysaccharides that have broad applications in the food sector and pharmaceutical industry. Based on the degree of sulphation (polyelectrolytes) in carrageenan, only Kappa and Iota carrageenan have the ability of forming a gel structure. The mechanical characteristics of their gels, however, is affected by the polyelectrolyte nature of their chains. Iota and kappa carrageenan provide elastic soft gel and brittle rigid one, respectively, in the presence of calcium and potassium salts as their favored ions; while their mixture provides a broad range of structures with unique textures. The combination of these two biopolymers would result in a broad range of unique textures for different applications. The aim of this Study was to determine the effect of chain association (molecular association) on the textural properties of kappa- Iota carrageenan mixed gel. The texture of gels was investigated through the puncture test to determine some properties including hardness, toughness, deformability modulus, resilience, yield point, and proportional limit. In addition, the stress relaxation test was applied to evaluate the effect of the chain association formed in the network on the stress decay parameter.
A commercial Kappa-carrageenan, Genugel type, and Iota- carrageenan, Genuvisco type without further purification were purchased from CP Kelco (Lille Skensved, Denmark). Potassium chloride (KCl) and calcium chloride dihydrate (CaCl2•2H2O) of analytical grade were purchased from Merck company. The mixtures were prepared in 2:1, 1.5:1.5 and 1:2 ratios and the final concentration of 0.3% w/w biopolymer. Both calcium and potassium chloride were added using a strategy adopted for each salt for keeping the same ionic strength of molar concentrations of 2.5, 5 and 7 mmol in the biopolymer dispersions. The mechanical properties of the gels were investigated using an XT. T2 Texture Analyzer (Stable Micro Systems, Surrey, UK). Peltier system was utilized in adjusting the temperature at 4oC. The samples were equilibrated at least 10 min before performing the test. Crosshead speed was adjusted at 10 mm/min to a 12 mm depth (50% from total length) from the surface of the samples using a 1 mm diameter cylindrical aluminum probe for puncture test and a 2 mm/min crosshead speed using a 75 mm diameter cylindrical aluminum probe in 20% strain was applied for the stress relaxation test during 60 second time interval. Pleg and Normand equation was applied for the determination of viscoelastic properties of samples.
Result & Among different methods in the mechanical study of biopolymer gel, the puncture test is a promising method due to its ability in applying normal and shear forces on and into the structure simultaneously. In the presence of calcium and Potassium salts, the same pattern in the puncture curve was observed with increasing of ionic strength in the medium. According to the chain association formed as a result of the ion type, the pattern shows a transient from the elastic to the plastic deformation with different limits. The hardness as a parameter that indicates a composite biopolymer network resistance to break up, showed a higher value for the network containing Potassium salt. It would be due to the formed intra chain association in the system. For calcium salt, the results revealed a small variation in the hardness parameter with increasing the ionic strength. The area under the curve of stress- time is defined as toughness of the structure. The network formed by the intra chain association in the presence of potassium shows a free chain movement which leads to a plastic deformation with absorbing more energy before breaking the gel structure. Concerning the type of chain association, higher values of deformability modulus in the gels containing calcium salt is reasonable. Resilience, yield point and proportional limit are the characters related to the network homogeneity and bond stretching. In the networks with no depletion region, applying an external force to the body would lead to a uniform change in the initial state of the structure. In this kind of netwoks, the force distributed in the whole structure uniformly and local stress is not created. The chain movement as a result of bond stretching, causes a back stress occurance in the structure. When the primary stress is eliminated, the accumulated back stress will make the polymer to return to its original form. Interweaving the network by the intra chain association will result in a homogenous network formation and subsequently, to a higher parameter values in the linear region. The large deformation measurements were performed through the stress relaxation test to study the response of the structure during the interval times and to evaluate the viscoelastic properties of biopolymers network. Longer stress decay time was observed for the network developed in the presence of Potassium salt. The result obtained by studying the stress decay rate was in agreement with the properties observed from the evaluation of the linear region in the puncture test. On the other hand, the deformability modulus values conform to the result from hypothetical asymptotic level of the normalized relaxation parameter.

Silymarin (SM) is a flavonoid mixture that has been extensively studied owing to its proven anti-diabetic effects. In the present study SM-loaded gum tragacanth-whey protein isolate cryo- and xerogels were prepared and their physico-chemical, textural, mechanical and microstructural properties were analyzed by Fourier transform infrared spectroscopy (FTIR), texture analyzer, N2 adsorption-desorption technique and scanning electron microscopy. Moreover, swelling rate of gels and their SM release profile were investigated in acidic and basic conditions. The results indicated that cryogels were highly porous incorporating a network of interconnected open pores. In contrary, xerogels microstructure was quite compacted with internal closed and isolated pores. The addition of gum tragacanth markedly improved physic-chemical, textural, mechanical and morphological properties of the gels, while silymarin increased porosity and weakened the mechanical strength and morphological characteristics of the gel networks. SM loading also decreased the swelling ratio of gels. These macroscopic changes were linked to molecular interactions amongst gum tragacanth, whey protein isolate and silymarin as confirmed by FTIR spectra. The results of release measurements revealed that cryogels lost 80% of their silymarin content during exposure to acidic and basic condition, but xerogels strongly retained it within their matrix and underwent only a 30% loss. Both types of gels showed the highest release rate in phosphate buffer solution compared to acidic pH. Data fitting with release kinetics models indicated that the dissolution mechanism was controlled by Korsmeyer-Peppas model.

In this study, Ginger oil in water emulsions were prepared by ultrasound with defined combinations of Arabic gum, xanthan gum, and three types of modified starch (N- CREAMER, N- LOK and CAPSUL) as the aqueous phase and ginger oil containing ESTER gum as the oil phase. After dilution of the emulsions with glucose syrup (10% w/w), their stability based on changes in particle size, droplet size distribution and viscosity were investigated in different generated pressures of solid carbon dioxide (with concentrations 0.5, 1, 1.5, and 2 percent) before and after pasteurization and during storage time within intervals (0, 7, 14, 21 days). Rheological studies of diluted emulsions indicated Newtonian behavior. Viscosity changes versus type of starch and different pressure of CO2 were significant. Experimental data showed that modified starches had a significant effect on the average diameter of droplets emulsion, so that the average diameter of the droplets in the presence of CAPSUL, N- LOK, unlike N- CREAMER were increased during storage. Also, the different levels of carbonation on emulsion droplets size changes showed a similar trend for all three types of starch for the time of storage. The overall trend of droplet size distributions during storage 21 days indicated only the diluted emulsions including N- CREAMER starch were stable without any significantly changes before and after pasteurization.

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.

Persian gum is an anionic polysaccharide, exudes from mountain almond tree. Unfortunately, there is no information about its interaction with unfolded proteins. The objectives of the current study are investigation of heating time on the properties of WPI and the complexes thereof. In this regard, first the effect of thermal processing (at 80°C, for 0-35 min) on the turbidity of whey protein isolate was surveyed at pH 4.0. The electrostatic interaction between treated WPI and Persian gum was also surveyed as a function of heating time and mixing ratios (2:1, 1:1, 1:2, 1:5, 1:10 and 1:20). Results indicated the significant increasing in the turbidity of treated WPI solutions (mainly after 25 min) with a high inconsistency leading to the precipitation due to the protein-protein interactions at low pH and formation of large aggregates. Addition of Persian gum (PG) caused the formation of WPI-PG complexes and meaningful increasing in the stability of the mixture solutions. Furthermore, the rheological measurements (0-100 S-1) showed that the mixture solution has pseudoplastic behavior with a large hysteresis loop and higher viscosity rather than the blank solutions, indicating the formation of proteinpolysaccharide complexes. By calculation of protein and polysaccharide in the supernatant and precipitation phases, the most biopolymer concentration in the precipitation phase was demonstrated for the 35-min-treated WPI. On the other hand, the amount of polysaccharide was increased in the precipitation as WPI:PG mixing ratio decreased.

Electrohydrodynamic atomization has recently been introduced as a safe method for encapsulation of sensitive bioactive compounds. In this regard, the parameters affecting the size and morphology of particles, owing to their key role in the protection and controlled release of bioactive compounds, are of paramount importance. In this study the influence of whey protein concentrate (WPC), gum Arabic and skim milk concentration as well as the operating voltage on the size and morphology of electrosprayed particles was investigated and the experimental data were then used for simulation of the process using two feed-forward artificial neural networks: multilayer perceptron and radial basis function networks. These models along with different threshold functions were employed to predict the viscosity, surface tension, electrical conductivity of polymers solutions, and the size of particles. The results showed that multilayer perceptron network comprising a set of 5 inputs and a single hidden layer containing 4 neurons with hyperbolic tangent activation function which was trained by Levenberg-Marquardt (LM) learning algorithm at 1000 epochs predicted the desired outputs more accurately than the radial basis function network. The determination coefficients (R2) for particles size, viscosity, surface tension, and electrical conductivity of polymers solutions were found to be 0.958, 0.9991, 0.996 and 0.967, respectively. Examination of the sensitivity analysis diagram of the predicted values by multilayer perceptron neural network versus experimental data revealed random scattering of points in the close proximity of the regression line with a high determination coefficient which clearly verifies the high accuracy of the model in predicting the outputs. It should be noted that size of particles as well as viscosity and electrical conductivity of solutions significantly increased with the rise of polymers concentration (p

Calcium alginate microhydrogels loaded with niosomes and liposomes were used to encapsulate caffeine as a model low molecular weight hydrophilic bioactive compound. To load niosomes and liposomes into alginate hydrogel network and to reduce the size of gel particles the feed solution was electrosprayed into calcium chloride solution. Successive freeze-thaw cycles were employed with a view to slow the release rate of caffeine from niosomes and liposomes. The results showed that niosomes was more efficient in caffeine encapsulation than liposomes. The release profiles confirmed the positive effect of freeze-thaw cycles on sustainable release of caffeine and that the niosome-loaded hydrogels had slower rate of caffeine release. Also, liposomes made of highly pure lecithin revealed more encapsulation efficiency as well as better release profile compared to those of commercial lecithin. Korsmeyer-Peppasmodel was found to appropriately describe the release of caffeine from particles based on Fickian diffusion. The findings of this study clearly demonstrated that niosome- and liposome- loaded microhydrogels could potentially be used to encapsulate food and pharmaceutical compounds for slow release applications. Moreover, electrospraying technique owing to its capability of producing uniform fine particles could be used as an alternative method for hydrogel preparation from natural polymers.

The purpose of this research was to encapsulate the bioactive compounds of saffron (colour, taste and aroma) in order to manufacture a high-economic-value product. For this purpose, the effect of different bio-polymers, Maltodextrin, Whey protein and Gum arabic on the stability of microencapsulated bioactive compounds of saffron with the spray dryer was evaluated. The result showed that the encapsulation efficiency and the amount of saffron compounds were highly affected by type of biopolymers, relative humidity and temperature during the drying process and storage. The picrocrocin and safranal content in microcapsules prepared with whey protein were at the highest compared to the other wall materials, whereas in the case of colour strength, maltodextrin showed better protection for the crocin .This research suggested that the microcapsules containing maltodextrin has a better quality in terms of both efficiency (mass production) and protection of bioactive compounds among other wall materials (whey protein and gum arabic) and can be recommended to the industry. At all the temperature examined, as the relative humidity increased, the loss rates of crocin, safranal and picrocrocin rose and reached its maximum at 75% relative humidity. The results showed that with increasing temperature and humidity, particularly at 45 ° C and 75% humidity, the spherical from (morphology) of micro-capsules has been changed and the number of cavities and dents widely increased. Also as the relative humidity increased, glass transition temperature of maltodextrin decreased.

One of the most interesting methods to develop novel rheological and textural properties in food formulation is the application of hydrocolloid blends. In this study, properties of tragacanth gum blends with qodoumeshirazi, farsi and locust bean gums were evaluated. By this purpose initially the rheological behavior of tragacanth, qodoumeshirazi, farsi and locust bean gums were evaluated individually at 0.2% total gum concentration. Further, the rheological behavior of tragacanth gum blend with the mentioned gums in ratios of 20:80, 40:60, 60:40 and 80:20 were investigated between 1.32 and 165 s-1 shear rates. Power law and Herschel-Bulkley models were used to described their rheological behavior.These results showed that all solutions had pseudoplasticbehavior. Among the individual gum solutions,qodoumeshirazi showed by itself yield stress. The consistency coefficient of tragacanth gum was considerably higher than other gums. The apparent viscosities of blend solutions of tragacanth- locust bean gums and tragacanth-farsi gums in the ratio of 20:80 were higher than individual gums, which revealed the existence of synergism between these groups of gums. Since,farsi, qodoumeshirazi and locust bean gums are cheaper than tragacanth gum; it is possible to have cheaper formulation by using them instead oftragacanth gum.

Proteins are food ingredients with critical functional properties and participation in developing food products. So far, functional properties of several plant proteins such as pea, chickpea and lentil, groundnut, beach pea and bayberry have been investigated. Nowadays, there is an increasing demand for plant proteins because they are available and inexpensive. Legume proteins are important plant protein sources. However, except for soy, due to the inadequate information about their structural and functional properties, they do not have appropriate application as functional ingredients in food products. Beans are a great source of nutrients such as protein, carbohydrate, dietary fiber, minerals and vitamins. Based on the several research reports, different dry beans have 15-25% protein and they are the second group of legume seeds, after soy, cultivated throughout the world. As mentioned earlier, insufficient information about structure of legume proteins is the main reason why they are unexploited in food industry. Therefore, the goal of this research was to evaluate the functional properties of proteins from three types of common bean (Speckled Sugar, Red Mexican and Great Northern bean). We also have attempted to evaluate the structure-function relation of these three sources of bean proteins because it is known that there is a direct relation between chemical conformation and the function of a protein which must be considered in food processing.
Protein of three types of common bean (Speckled Sugar, Red Mexican, and Great Northern) was extracted (pH 9, water flour 10:1). Afterwards, their physicochemical (including protein electrophoresis pattern, solubility, hydrophobicity), and functional properties (including emulsifying capacity, heat stability, gelation and foaming capacity) were evaluated to understand how bean protein structure influences its structure. Electrophoresis pattern was obtained based on 2 dimensions (pH and molecular weight). Protein solubility was evaluated by biuret method at pH range 3-9. ANS (8-anilino-1-naphthalenesulfonic acid) was used to measure surface hydrophobicity (pH 3-7).Emulsion samples (1% protein, 25% sunflower oil, pH 3-7) were produced, then emulsion capacity and emulsion heat stability (80°C for 30 min) were evaluated. Gelation of proteins was evaluated at protein concentration of 4-12% at different pH values (3-7). Foaming capacity (%) was measured as the difference between volume after and before whipping. Foam stability (%) was recorded during 90 minutes.
Results showed that all proteins were rich in Phaseolin. In fact, this fraction was the major building fraction of all three bean proteins. Evaluation of solubility indicated that isoelectric point of three proteins was located at acidic pH range (pH 4.5). Results confirmed an indirect relation between protein solubility and hydrophobicity. All three protein isolates, similar to the other legumes protein, were more soluble at alkaline pH, while the highest surface hydrophobicity was observed at pH 3. Generally, Speckled Sugar bean protein had the most solubility, while Great Northern bean protein showed the highest surface hydrophobicity. Among three bean protein isolates, Speckled Sugar bean protein performed better as an emulsifier, whereas Great Northern bean protein formed gel at the lowest concentration (6% at pHs 3 and 7). In addition, foaming was higher at acidic pH (pH 3). Therefore, it was concluded that emulsifying capacity is mostly influenced by protein solubility, while gelation and foaming properties are affected by protein hydrophobicity. As the main consequence, the results achieved in this research confirmed that there is a direct relation between structure and the function of a protein. In fact, special structural properties are responsible for special functions.

Saffron with the botanical name of Crocus sativus L., is the most expensive spice in the world. Introduction of a suitable method for the extraction of these bioactive compounds, as well as the technological and economical issues are important points to be considered. The aim of this study is to develop the most economical method to extract the bioactive compounds of saffron.
In the present study the extraction conditions of crocin, safranal and picrocrocin in the binary solvent system (water: ethanol and water: acetone) as well as ternary solvent system (water: acetone : ethanol) were investigated in terms of different ratios of solvents and different ratios of solvent to saffron.
The best extraction conditions were found with the binary solvent system of ethanol: water; 3:2 with a solvent ratio of 12 ml per gram of saffron and also applying the ternary solvent system of water: acetone: ethanol (40:45:15) per gram of saffron at 25° C for 16 hours to extract the optimal saffron bioactive compounds. The amount of crocin, safranal and picrocrocin in the aqueous extract of saffron were measured 229.05, 35.17 and 75.53 respectively for the binary solvent system of ethanol: water and 272.96, 40.03 and 13.6 respectively for the ternary solvent system of water: acetone: ethanol (40:45:15).
Based on the need for the desired color and flavor in various food processing, and considering the economical aspects, each of the proposed extraction method might be used.

Microbial growth in food products decreases the food shelf life and increases the risk of foodborne diseases. There are various methods for monitoring the microbial growth and consequently the incidence of food spoilage; e.g. food spoilage monitoring sensors. In this research we aim to investigate the feasibility of producing the cellulose acetate (CA) film incorporated with bromothymol blue (BTB), as a kind of halochromic sensor. The 4% (w/w) cellulose acetate solution with 0.5, 1 and 1.5% bromothymol blue (wdye/wpolymer) and 0.5% glycerol (as plasticizer) was used to produce the pH sensitive films. The halochromic behavior of sensors in pH 5-9 buffer solutions were studied through the L*, a*, b*, and total color difference (ΔE*) measurements. The reaction of the produced films and the leakage of the dye at different pH values were also studied. The results showed the significant effect of dye and pH (P

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.

To improve structure of the electrospray fabricated calcium alginate microhydrogels in order to control the swelling and release properties, Poly (vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) PVP were used and structure of the microhydrogels were reinforced by two freezing and thawing cycles. The particles did not show any swelling in HCl (pH=1.2). Swelling in the phosphate buffer (pH=7.4) showed amending effect of PVA and PVP and freeze-thaw cycles on the particles. In phosphate buffer media the freeze dried calcium alginate particles (ALG), the particles which improved by PVA and PVP (FD) and particles reinforced by freeze-thaw cycles (FT) showed swelling of 244.65, 152.15 and 126.34% respectively after 8 hours. On the other hand release rate of caffeine as a hydrophilic compound delayed in the FD and FT particles. According to the FTIR spectra, caffeine was entrapped physically in the particles. Results showed that calcium alginate particles reinforced with PVA and PVP especially those were undergone on freeze-thaw cycles could be applied for more efficient encapsulating of bioactive compounds without any chemical cross-linkers.