ma mohammadifar

Berberis vulgaris, an Iranian native plant, includes valuable compounds such as berberine with therapeutic, health-promoting and nutritional effects. However, major parts of this plant are discarded as wastes. The major aims of this study were optimization of berberine extraction conditions from the whole plant with maximum antioxidant activity, the extract microencapsulation using complex coacervation and two biopolymer gelatin/flake tragacanth (Astragalus rahensis) and analysis of the physical characteristics of the moist microcapsules.

Berberine extraction was optimized using response surface methodology based on three extraction parameters of time, temperature and solvent:water ratio at three levels and five central points. The berberine concentration was analyzed using high-performance liquid chromatography and its antioxidant activity was studied to investigate the optimized conditions. The optimum extract was microencapsulated using complex coacervation and gelatin/tragacanth with three ratios of 1:1, 2:1 and 1:2 w/w. Furthermore, yield, efficiency, particle size, solubility and the microstructural and release characteristics of the wet microcapsules were characterized.

Optimized extraction conditions with 0.88 desirability included 0.5 h, 22.9 °C and 75% solvent:water ratio. The average surface size of the microcapsules was in the range of 71.31–90.15 μm. Samples with 2:1 ratio indicateds the maximum yield 95.1 and sample with 2:1 ratio showed the maximum solubility of 10%. Efficiency in all samples were similarly 96% ±1.

Complex coacervation using gelatin/tragacanth with a ratio of 1:2 was developed to produce wet microcapsules of the optimum extract of berberine with the highest yield and efficiency and low solubility as well as particle sizes of smaller than 100 μm.

Despite the production and consumption of gluten-free breads in Iran, which, the bulk of formula is from rice, impact of rice characteristics on the quality of produced bread has not been investigated. This study aimed to compare the amount of broken rice varieties’ macronutrients from two different climate zones and to study the dough rheology, sensory properties and quality of produced bread from these varieties in a commercial gluten-free bread formula
In this study, the effects of four different broken rice varieties (Hashemi, Tarom, Khouzestan, Lenjan) from two different climate zones on dough rheology (dynamic oscillatory test) and quality parameters (color, specific volume, textural properties and sensorial properties) of a commercial gluten free bread was investigated. Flour characterization and hydration properties, and gelatinization temperatures were also assessed.
Significant differences were observed in proximate analysis and hydration properties of different varieties. Gelatinization temperatures and dough rheology showed correlation with the damaged starch contents. Specific volume of the breads did not have any correlation with damaged starch content nor the amylose content but showed a significant correlation with WBC. Crumb hardness of the breads had positive correlation with elastic modulus of the dough and WBC. Darker colors of bread were preferred according to the crumb color and sensory evaluation test.
Based on the outcomes of bread quality attributes, Khouzestan (warm and dry region variety) which is a cheaper rice variety was the most appropriate variety for gluten free bread production. Moreover, rice varieties being used in companies are not necessarily the best ones for gluten free bread making.

Nowadays, demands for hydrocolloids which improve the rheological properties of foods as well as retain their properties under the influence of food additives have increased. In this study, dilute solution properties were employed to understand the molecular and conformational properties of Alyssum homolocarpum seed gum (AHSG), in presence of sucrose and lactose. The model of Tanglertpaibul & Rao was selected as the best model for the estimation of the intrinsic viscosity. It was shown that except for water, the solutions of sucrose and lactose are poor solvents for AHSG as indicated by a decrease in intrinsic viscosity, swollen specific volume, shape function, and coil dimensions. As the sucrose and lactose concentrations increased, the coil radius decreased. The reduction in the shape and swollen volume parameters in the presence of sucrose and lactose as compared to the sugar-free solution indicated the negative effect of the opted sugars on the molecular volume of the gum. Evaluations of the dilute solution properties of the gum in sucrose and lactose solutions revealed that the existence of a conformation tending to ellipsoidal shape and the probability of the conformation of random coil with no molecular entanglements in AHSG solutions.

Collagen is a protein with several applications in the pharmaceutical, cosmetic, medical and food industries that is prepared from different sources such as cow, pig, poultry and fish. In this study, optimization of the extraction of collagen from eggshell membrane was examined.
The efficiency of extraction of collagen in different concentrations of sodium hydroxide (2/0-2 /1 N) at different treatment times periods (6-36 hours), different concentrations of pepsin (U/mg90-15) and enzymatic hydrolysis times (6-60 hours) was studied with response surface methodology (RSM). Also the properties of eggshell membrane collagen were characterized by amino acid analyzer, SDS- PAGE and solubility.
The most important factors for extraction of collagen using RSM according to central composite design were optimized. Optimum extraction conditions were as follows: NaOH concentration of 0.76 N, alkali treatment time of 18 h, enzyme concentration of 50 U/mg and hydrolysis time of 43.42 h. The experimental extraction yield under optimal conditions was found to be 30.049%. Collagen solubility in pH=3 and NaCl concentration of less than 2% was determined. The analysis showed that Glycine having 322/1000 amino acids as the most amino acids and the immune-acid (sum of Proline and hydroxylproline) of collagen was 19.5 %. SDS- PAGE protein pattern revealed two different a (α1 and α2) components with β and γ chains.
Collagen was extracted from eggshell membrane with optimum extraction efficiency, which can be used in film production, gelatin and functional food components to maintain health and control chronic diseases.

Dough is an intermediate product of bakery production that represents physicochemical properties of raw materials and also qualitative aspects of the final product.Due to the high performance of artificial neural networks in educability and parallel processing of data with non-linear relations, the purpose of present research is providing suitable models for predicting rheological properties of dough based on the physicochemical properties of flour. A range of flour samples produced in the factories of various regions and provinces of Iran were collected and seven physicochemical properties of them were evaluated. Oscillatory tests of stain and frequency sweep were done on the dough of samples, and two important parameters of them were selected for modeling. After training, and determining the specifications of networks with genetic algorithm and testing them, the sensitivity of output to input parameters was evaluated. Developed networks are four-layer perceptrons in which the first network, with removing gluten index and particle size index of flour, has 5 neurons in input layer and 15 neurons in the first and second layers for prediction of the incept, and the second has 7 neurons of input layer, 24 neurons in the first hidden layer and 17 neuron in the second hidden layer for predicting the slope of fitted model on frequency sweep. Developed networks predict rheological properties of dough with correlation coefficient more than 97%. Gluten index and zeleny number are introduced as important parameters on changing the rheological properties of dough. Artificial neural network-genetic algorithm is a powerful method in predicting dough's rheological properties. Sensitivity analyses of optimum network indicate in the importance of flour's physicochemical properties in predicting the changes in the fundamental rheological properties of dough.

The encapsulation of nutraceutical compounds in lipid-based carrier systems، such as nanoliposomes، is effective in preserving their native properties throughout their shelf lives. Liposomes are widely used in food industries because of their benefits، which include possible large-scale production using natural ingredients، entrapment and release of water-soluble، lipid-soluble، and amphiphilic materials and biodegradability. The present study prepared vitamin D3 nanoliposomes and characterized them using differential scanning calorimetry (DCS) and scanning electron microscopy. Nanoliposomes containing vitamin D3 were prepared using different quantities of phosphatidylcholine (PC) and cholesterol (60-0، 50-10، 40-20، 30-30 mg) equivalents (8-0، 7-3، 5-5، 4-8 mM) using thin-film hydration and sonication. DSC and determination of particle size and encapsulation efficiency were carried out to determine the physicochemical properties of the liposomes. The results shows that particle size was 78-89 nm and size distribution (span) was 0. 77- 0. 84 nm. In all formations، the encapsulation efficiency of vitamin D was >90%. The DSC thermogeram of the vitamin-loaded liposome showed the disappearance of the melting endothermic peak of vitamin D3 and a major endothermic peak at 227°C، indicating that vitamin D3 complex formed with the bilayers and was completely encapsulated by the lipid matrix of the nanoliposomes. The lower melting temperature of proliposome over bulk lecithin can be attributed to its small particle size. SEM analysis showed that the surface morphology of all freeze-dried liposome samples had a porous structure. Vitamin D3 nanoliposomes were prepared successfully using the thin film hydration-sonication method that achieved all expected features.

The mechanism of stabilization of oil-in-water emulsions using natural biopolymers has been a focus of many studies. The present study emphasized the importance of using native sources or a mixture of natural biopolymers as a substitute for small molecule surfactants. It also determined the effects of different concentrations of two types of Iranian gum tragacanth on the stability، rheological properties، particle size، and interfacial tension of oil-in-water emulsions. The emulsion stability of four concentrations (0. 2%، 0. 3%، 0. 4%، 5/0 w/w) of two types of gum tragacanth (Astragalus gossypinus and Astragalus fluccosus) was measured using emulsion stability tests. Then، to find and monitor the mechanism of stabilization، the rheological properties of the emulsions were measured using a rheometer immediately after production and 35 d after production at 25○C. Particle size distribution was determined using laser diffractometry and interfacial tension was measured using a tensiometer. The results showed that flow behavior parameters، particle size، and interfacial tension parameters were significantly affected by the concentration of gum tragacanth. The severity of this effect was influenced by the type of gum. Based on stability index data، samples containing only 5. 0% A. gossypinus showed higher stability than for the other concentrations. The use of appropriate types and concentrations of gum for oil-in-water emulsions can improve the stability of samples by affecting the physical and physicochemical properties of this model system.

Numerous attempts have been made to replace calf rennet with other milk-clotting proteases because of limited supply and high prices of calf rennet. Fruit of Withania coagulans (solanaceae)، a medicinal plant rich in milk-cloting proteases، have been traditionally used in the south of Iran as a plant coagulant for cheese-making. No systematic study on the characterization of W. coagulans milk-clotting enzyme has been conducted so far. The purpose of this study was to extract، partially purify and characterize the milk-clotting enzyme from W. coagulans. An enzyme extract was prepared from the fruit of W. coagulansusing using a 0. 85% NaCl solution، and the milk-clotting activity and characteristics of the milk-cloting enzyme (effect of temperature، pH، enzyme concentration and thermal stability) were assessed. The extract was partially purified، and the molecular mass of the crude extract and the fractions with the highest milk-clotting activity were determined by SDS- PAGE. The optimal temperature and pH for the enzyme were 70˚C and 4، respectively. Partial purification showed that the milk-clotting activity of the enzyme purified with 50% ammonium sulphate was greater than samples purified with other ammonium sulphate solutions at other concentrations. The molecular mass of this fraction using SDS-PAGE showed two bands، namely، 66 and 29 kDa. An important characteristic of the enzyme was its excellent thermal stability; it retained 74% of its milk-clotting activity at 60˚C for 30 min. It seems that W. coagulans proteases can be used as a suitable source of enzyme in the dairy industry as an alternative clotting agent.

Nowadays, many food systems, cosmetic and pharmaceutical products are consisted of emulsions. The formation of emulsions with membrane technique has attracted considerable attention in food industry due to its high energy efficiency. So, in the present study, the advantages, limitations and the factors which affect the efficiency of process are discussed. Factors which influence the formation of emulsion with membrane are diameter of pores in membrane, droplet size distribution, pressure gradients, the velocity of continuous phase, type and concentration of emulsifiers. Membrane technique is an appropriate and easy process for producing emulsions. The major advantages of membrane homogenizers are their ability to produce emulsions with very narrow droplet size distributions.

Gums play roles such as stabilizers, emulsifiers, texture improvement etc in food systems. Physico - chemical properties of gums determine their applications. In this study, some properties of Zedo gum, which exudes from Amygdalus Scoparia, were investigated. We harvested Zedo gums from the trees in Kerman province and separated into white, yellow and red groups. The gums were tested for protein, fat and ash content according to AOAC. Na, Fe, Mg, Ca, K and Zn were determined by ICP and total carbohydrate by phenol sulfuric method. Thermal analysis was done from 30 to 600 °C. Molecular mass was carried out by size exclusion chromatography and rheological behavior was assayed by a Physica MCR 301 rheometer at 25 °C on 2% (w/w/) dispersions. Zedo gums showed significant difference in some compositions and thermal analysis. All samples contained high molecular weight polysaccharides of above 1million Dalton. An increase in strain caused a reduction in storage and loss moduli. No jell-like behavior was observed among the samples and high temperatures had lowering effect on their viscosities. Zedo gums samples with three colors were investigated. It was demonstrated that some phisico-chemical and rheological differences existed among them. The results showed that Zedo gum and gum Arabic were two quite distinct polysaccharides with different properties.

Nowadays, a wide variety of natural and processed products can be classified as emulsions. These systems have attracted considerable attention in food industry due to physicochemical and rheological properties.but the main limitation of these systems is thermodynamically unstable. So, in review present study, many attempts have been carried out to understand the mechanism of stabilization. Sciencedirect, Springer and Google scholar databases were searched in order to achieve the desired articles. Review and research studies that have been conducted from 1980 till 2012, were recruited in this investigation. Previous studies showed that emulsions can be formed kinetically stable (meta stable) by using substances known as emulsifiers. Use of natural biopolymers as a substitute for small moluecle surfactant can be effective because they did not have side effects on people’s health. The surface activity of some polysaccharides can be explained by the presence of acetyl groups.SO surface-active ingredients can be adsorbed rapidly at oil-water interface and stabilized the emulsions by lowering the surface tension.

Investigation of the colloidal behaviour of protein-polysaccharide systems is becoming increasingly important to provide a foundation for their applications in areas such as production of biopolymer micro-and nano-particles، designing food analogues، and microencapsulation technology. The aim of the present study was to investigate the pH-induced critical transitions during associative phase separation between β-lactoglobulin (BLG) and tragacanthin (T). The formation of electrostatic complexes in BLG/T dispersions (0. 3wt. % total concentration; BLG: T ratio 2:1) was investigated as a function of pH (2. 00-6. 00) by spectrophotometry and particle size analysis. In addition، coupling of slow in situ acidification of the blend، with glucono-delta-lacton، and rheometry were used to monitor the structural transitions during the associative phase separation. The influence of salt type and concentration on the formation of micro-particles were also determined. The formation of soluble complexes started at pH ~5. 20، and at pH ~4. 85 the aggregation of intrapolymeric complexes occurred، followed by a bulk phase separation at pH ~4. 30. The data indicated that coacervation occurred at pH 4. 15. Finally، the mixture returned to a mono-phasic system at pH 2. 5. Particle size analysis showed that the assembled structures experienced a contraction process upon complexation. Rheometry provided deeper insights into the colloidal behaviour of the system and the results were in good agreement with quiescent pH-induced transitions established by HCl titration. The formation of the micro-particles was strongly salt-dependent. Under controlled pH conditions، electrostatic interactions between β-lactoglobulin and tragacanthin can be used to form a variety of biopolymer particles. These biopolymeric micro- and nano-particles may be used in the food industry as natural delivery systems or fat-replacers. Keywords: β-Lactoglobulin، Tragacanthin، Protein-polysaccharide interactions، Associative phase separation، Biopolymer micro-particles

Date syrup، as a native and nutritious additive، is one of the best choices for milk flavoring. In this study، some of the rheological، physical and sensory properties of date milk made from three different concentrations of two types of Iranian gum tragacanth، as a substitute for imported gums، were determined. Rheological properties of samples of date milk containing three different concentrations (0. 1%، 0. 2%، 0. 3% w/w) of two types of gum tragacanth (Astragalus. gossypinus and Astragalus. rahensis) were measured using a rheometer at 3○C، and at three different time periods (one، two and three days) after production. Particle size distribution was determined by laser diffractometry، and colorimetric assays were done by using reflection spectrometer. Sensory analysis was performed by 25 semi trained panelists، using a 5-point hedonic scale. Findings showed that flow behavior parameters، particle size and color parameters (L*، a*،b*) were significantly affected by concentration of the gum tragacanth and the impact severity was influenced by the type of gum. Based on sensory evaluation، samples containing 0. 3% A. gossypinus and 0. 2% A. rahensis showed higher desirability than others. Using an appropriate type and concentration of gum in date milk formulation can improve the milk texture and mouthfeel by affecting the particle size and flow behavior.

Phenylketonuria is a hereditary disease caused by a lack or deficiency of the enzyme phenylalanine hydroxylase, its most severe clinical manifestation being irreversible mental retardation. Presently, the only therapy available is the dietary restriction of phenylalanine. The objective of this study was to produce laboratory-scale low-phenylalanine milk to be used as a dietary supplement by phenylketonurics. Low-phenylalanine milk can be used to make a variety of palatable, low-phenylalanine foods and beverages. Three milk hydrolysates were prepared enzymatically (1g of enzyme/100 g of substrate), using a protease from Aspergillus oryzae and papain, separately and in combination (0.5 g of either enzyme/100 g of substrate), followed by adding different amounts of activated carbon (0.3, 0.9, and 1.5 g) to them to remove phenylalanine. The combination of Aspergillus oryzae protease and papain, along with the use of 0.9 g activated carbon in the post-hydrolysis process, resulted in the lowest final phenylalanine content. The best condition for removing phenylalanine from milk was use of a combination of Aspergillus oryzae enzyme(0.5g of enzyme/100g of substrate) and papain (0.5 g of enzyme/100 g of substrate) with 0.9 g activated carbon in the post-hydrolysis process, resulting in removal of 99% of the phenylalanine.

Chocolate is a popular product for cunsumers in different ages . Chocolate sweetness  is related to the sucrose in its formula , it can be replaced by sweeteners like low digestible carbohydrates (LDCS) .The results would be reduction in calories and glycemic index and prevention of tooth decay. The aim of this study was to replace  the sucrose with the inulin (as dietary fiber) and tagatose (as natural keto hexose  with sweetness similar to sucrose). The ratio of the replacements were 100:0 , 75:25 , 50:50 , 25:75 and 0:100 inulin:tagatose in milk chocolate formula and the chemical and rheological properties of samples were tested. Results indicated that when the amount of inulin reduced and amount of tagatose  increased in chocolate formula, moisture contents reduced but aw values increased . The hardness of samples was related to the percentage of tagatose when tagatose added  to the formula, hardness was increased and the hardness of sample with 100% tagatose and control were comparable. In color parameters the least amounts of l* ,a*,b*,c* and hue° were observed in chocolate with 100% inulin which they went up when amount of tagatose was increased in formula. When inulin reduced in samples,  and  incresed and the lowest real and linear yield stress occurred in the sample with 100% inulin. By reduction of inulin, apparent and plastic viscosity were reduced. The least amount of apparent and plastic viscosity was observed in sample with 25%inulin-75% tagatose and the viscosity in formula with tagatose had no significant difference with control. Flow property index also reduced with reduction of inulin. Results showed that the samples with 50% inuin -50% tagatose and 25% inuin -75% tagatose  and 100% tagatose were the best ratio of the sugars as replacement of sucrose in formula, the two formers formulas are the best formula from nutrition point of view and are considered  as a functional food.

Doogh is an Iranian traditional beverage based on yoghurt. In this product, serum separation occurs during storage due to its low pH. In recent years, studies have been conducted on the stabilization of doogh using hydrocolloids. The objective of this study was to compare the effects of different species of gum tragacanth (Astragalus gossypinus, Astragalus rahensis, and Astragalus fluccosus) on the stabilization and rheological properties of this typical Iranian dairy drink during storage. Gum solutions were added to Doogh samples prepared from yoghurt made with skim milk. Phase separation was measured using graduated cylinders during storage (30 days), and particle size distribution at ambient temperature was determined by laser diffractometery. Furthermore, steady and unsteady rheological tests were carried out using a controlled shear rate rheometer (CSR) at 3°C. Finally, sensory analysis was performed with 30 panelists familiar with the product, using a 5-point hedonic scale. In the samples containing 0.3% (w/w) A. gossypinus no phase separation occurred during the 30-day period. The data on particle size distribution indicated that addition of gum tragacanth resulted in a reduction in the size of aggregated particles, specially in the sample containing A. gossypinus. The apparent viscosity in this sample was higher than in the other samples. Also, its sensitivity to frequency (range = 0.01-10 Hz) was much less, which is very important from an industrial point of view. In addition, based on the sensory evaluation data, the sample containing A. gossypinus was the most acceptable product. The higher content of uronic acid and insoluble part of A. gossypinus can be the most probable reasons for the stabilized dispersion caused by A. gossypinus as compared to that caused by the other two species at the same concentration (0.3% w/w) in doogh.

Nowadays, acid-induced milk protein gels are used extensively in the dairy industry and are the base of many food products. Therefore, a deeper fundamental understanding of the effects of process parameters and system components on the mechanisms of gel formation and final gel properties in real and model systems is important for researchers and industries. The present study was designed to investigate the effects of casein-to-whey protein ratio, incubation temperature, and heating temperature on viscoelasic properties of the final gel in a model system. Samples of solutions with different casein-to-whey protein ratios (2.1:0.9, 2.4:0.6 and 2.7:0.3) were prepared and refrigerated overnight. This was followed by heating the samples at different temperatures (70, 80, or 90°C) for 15 minutes using a water bath and cooling to incubation temperatures (25, 35 or 45 °C). In the next step lucono-δ-lactone was added and the samples were transferred to a rheometer. The gelation process was monitored by the time sweep oscillatory test. A second-order polynomial model was fitted to the experimental data and the optimum response was determined using the Minitab15 software. Incubation and heating temperatures influenced significantly (P<0.001 and P<0.01, respectively) the G'200 value (storage modulus value of the final gel measured 200 minutes after addition of GDL). The casein-to-whey protein ratio had no significant influence on the G'200 value. Increasing the incubation temperature led to a decrease, whereas increasing the heating temperature led to an increase, in the G'200 value. The maximum value of G'200, 268/93 Pa, was obtained at the presence of 2.6152% (w/w) casein and at incubation and heating temperatures of 25 ºC and 90 ºC, respectively. Smaller quantities of casein and higher incubation and heating temperatures shortened the length of time required for gel formation. Finally, increased incubation temperatures and decreased heating temperatures led to increased the damping factor (tan δ). The effects of different process parameters on the viscoelastic properties of dairy gels can be determined and characterized by oscillatory rheometry. The findings of this study show that incubation temperature is the most effective factor, whereas casein-to-whey protein ratio has no significant effect on the final gel strength.

Chocolate is very popular among consumers of all ages. However, its consumption is limited for the obese and diabetic people due to its high energy and sucrose contents. Replacing sucrose by low digestible carbohydrates (LDCS) will result in lowering its energy content and glycemic index, as well as in preventing tooth decay. The objective of the present study was to investigate the effects of replacing sucrose with 2 sugar substitutes, namely, D-tagatose and inulin, on the physical, chemical, rheological and sensory properties of dark chocolate Inulin, a dietary fiber, and D-tagatose, a natural keto-hexose with a degree of sweetness similar to that of sucrose, were used as sucrose substitutes in dark chocolate formulas. The inulin:tagatose ratios in the mixtures were 100:0, 75:25, 50:50, 25:75, and 0:100. The physical, chemical, rheological, and sensory properties of chocolate samples prepared with the mixtures were determined. With a reduction in the inulin content and an increase in the tagatose content, the moisture contents of the chocolate samples decreased, while their aw increased. Increased D-tagatose resulted in increased hardness of the samples, the sample with 100% being the hardest, comparable to the control (sucrose) value. With regard to color indices, the least amounts of L*,a*,b*,c* and hue° were observed in chocolate samples with 100% inulin. Increasing D-tagatose led to increases in the color indices. The data also showed that reductions in inulin resulted in decreases in apparent and plastic viscosity and increases in τ0 and τ1. Thus, the lowest real and linear yield stresses were found to be in the sample with 100% inulin. The least apparent viscosity and the lowest plastic viscosity were observed in samples with 25% inulin-75% tagatose and 100% tagatose, respectively, with no significant difference with the control value. Overall acceptability of the chocolate samples increased with increasing the D-tagatose level. It can be concluded that in chocolate formula samples an inulin-tagatose ratio of 25%-75% and 100% tagatose are the best sucrose substitutes. As inulin is a dietetic fiber and tagatose and inulin have prebiotic properties, chocolate samples prepared using them are also desirable from a nutritional point of view and can be considered as functional foods. Keywords: Dark chocolate, Inulin, Tagatose, Stevia, Rheology

Due to their nutritional, physical and chemical characteristics, mycoproteins, produced in the process of fungal growth, have been proposed to be used as a food additive for man. In this study a central composite design was applied to assessing the effect of seed size and initial concentrations of carbon and nitrogen sources on mycoprotein production by Fusarium venenatum (ATCC20334) from date sugar. Chemical composition (percent dried cell weight, nitrogen, moisture, and ash) and pH of the substrate were determined. Vogel culture medium was used for maintenance and inoculum preparation, and incubation was done at 30 °C for 72h. Dried cell weight was measured by the oven method. The experimental results were fitted to a full quadratic second order polynomial equation and the optimization of response was done with Minitab 14 software. Optimum conditions were determined and a confirmation test was conducted. The regression coefficient of the model presented for mycoprotein production (based on dried cell weight) was 98.0%. The optimum conditions for the mycoprotein production included a seed size of 15.39 % v/v, and a carbon and nitrogen source of 20 and 4.35 g/L, respectively. The predicted value for the optimum production of dried biomass was 5.032 g/L. The reconfirmation test was conducted at the optimum conditions and the result obtained was 4.84 g/L of biomass production. The regression coefficient indicates accuracy and suitability of the model for the experimental data. By changing the inoculum conditions and the chemical composition of the culture medium, optimal growth of Fusarium venenatum and, consequently, maximum biomass production, can be achieved. Use of date syrup as an available and domestic Iranian substrate for modification of Vogel medium makes possible protein production at an industrial scale in surface culture.

Many studies have been carried out on structural and functional properties of gums from different sources. However, there is not much information available on the properties of gum exudates from different species of Astragalus. The objective of this study was to investigate and compare the chemical composition and rheological properties of two species of Astragalus under different conditions with regard to concentration, temperature and ionic strength.

Moisture, ash and protein contents of the samples were determined according to the Iranian official standards, while determinations of minerals were done using ICP-AES. All rheological measurements were made using Physica MCR 301 rheometer (Anton Paar). In addition, the flow behavior index (n) and consistency index (m) as parameters of power law model were computed, and the temperature dependency of consistency coefficient was assessed by fitting the Arrhenius model.

The moisture and ash contents of A. floccosus were higher, and its protein content was lower, than those of A. rahensis. At all concentrations and temperatures, the results of apparent viscosity versus shear rate for each two species were found to exhibit a clearly shear thinning behavior. At all concentrations and temperatures and shear rates, A. floccosus had a higher apparent viscosity. At similar concentrations and temperatures, the magnitudes of parameters (m) and (n) for the A. floccosus was, respectively, higher and lower than that of the A. rahensis.

In different food processing operations (stabilizing of soft drinks, using fat replacers, microencapsulation, and appropriate mouthfeel), the use and application of gums is based on the exact knowledge of their functional properties. In this study, it has been shown that different species of gum tragacanth have different characteristics. Therefore, in the processing of different foods (dairy, cereal, soft drinks, sauces, etc.), appropriate species of gum tragacanth should be selected and used.