Effect of Calcium Salts on the Firmness and Physicochemical and Sensorial Properties of Iranian Black Olive Cultivars.

Black olive has become one of the most prestigious olives processed in the olive industry, and its processing has been increased recently in different countries. The firmness of black olives may be changed by the processing methods, fermentation, and solution salts. In this study, the employment of CaCl2, Ca-acetate, and Ca-lactate during the processing of some Iranian black olive cultivars, including Mari, Zard, Rowghani, Shengeh, Dakal, Dezful, and Fishomi, was evaluated in terms of physicochemical and phenolic compounds and textural attributes. The results showed that Ca-lactate improved the firmness of the Mari cultivar from 1455 to 1765 N/100 g in the pitted olive, and the same trend was obtained for the other cultivars. Ca-acetate improved the black shiny color of the Mari cultivar from 4.36 to 4.85 and the sensorial properties of the black olives, including gustatory and kinesthetic sensations, were improved by using a Ca-lactate solution. The application of calcium salts in the salt-free preservation solutions imparted neither bitterness to the olives nor discoloration. The highest amounts of acid (1.42-1.56%), fructose to mannitol ratio (1-1.2), and phenolic compounds (955-963 mg/kg) were found for the Zard cultivar. Furthermore, the residual content of oleuropein was higher when CaCl2 was employed (357 mg/kg). All of the calcium salts improved the firmness of the black olives, although the maximum firmness was observed for the Ca-lactate. Consequently, the formation of a black shiny color is related to the diffusion of phenolic compounds; however, this needs further investigation to determine which kind of phenolic compound is responsible for its black color.

Textural and Rheological Properties of Sliceable Ketchup.

This study investigates the effect of different mixtures of gums [xanthan (Xa), konjac mannan (KM), gellan, and locust bean gum (LBG)] on the physical, rheological (steady and unsteady), and textural properties of sliceable ketchup. Each gum had an individually significant effect (p < 0.05) on viscosity; however, the addition of Xa in combination with other gums had a greater effect on viscosity. By increasing the use of Xa in ketchup formulations, the amount of syneresis decreased such that the lowest amount of syneresis related to the sample prepared with 50% Xa and 50% gellan. Although the use of different levels of gums did not have a significant effect on the brightness (L) and redness (a) indices (p < 0.05), the use of different ratios of gums had a significant effect (p < 0.05) on the yellowness (b) index. The effect of different levels of gums used had a significant effect only on firmness (p < 0.05), and their effects on other textural parameters were not statistically significant (p > 0.05). The ketchup samples produced had a shear-thinning behavior, and the Carreau model was the best model to describe the flow behavior. Based on unsteady rheology, G' was higher than G" for all samples, and no crossover between G' and G" was observed for any of the samples. The constant shear viscosity (η) was lower than the complex viscosity (η*), which showed the weak gel structure. The particle size distribution of the tested samples indicated the monodispersed distribution. Scanning electron microscopy confirmed the viscoelastic properties and particle size distribution.

Effects of Concentration and Heating/Cooling Rate on Rheological Behavior of Sesamum indicum Seed Hydrocolloid.

Hydrocolloids are known as natural hydrophilic biopolymers that can contribute viscosity and gelation in solution, as well as nutritional benefits, thus, they are widely used in the food industry. In our work, hydrocolloid was isolated by aqueous extraction of Sesamum indicum seed at 80 °C and pH 8.0. The chemical composition and functional properties of Sesamum indicum seed hydrocolloid (SISH) were characterized, and the effects of concentration including 1%, 2%, and 3% as well as heating/cooling rate (1, 5, and 10 °C/min) on the rheological behavior of SISH dispersions in aqueous solution were investigated. The viscoelastic properties of SISH dispersions were characterized by small-amplitude oscillatory shear measurement. The resultant SISH consisted of 60.95% carbohydrate and 23.32% protein, and was thus endowed with a relatively high water-holding capacity, solubility, appropriate emulsifying and foaming properties. Rheological results revealed that the aqueous dispersion of SISH exhibited a non-Newtonian shear-thinning flow behavior. The viscoelastic moduli changes were found to be dependent on SISH concentration, temperature, and heating/cooling rate. Increasing SISH concentrations from 1% to 3% promoted the development of stronger cross-link network. The mechanical spectra derived from strain and frequency sweep measurements showed that the storage moduli were always higher than the loss moduli, and the loss tangent was calculated to be above 0.1 and below 1.0. Furthermore, both moduli had slight frequency dependency, and the complex viscosity exhibited an almost linear reduction with the increase of frequency. Therefore, SISH dispersion behaved as a weak gel-like system. The hysteresis of viscoelastic moduli during heating and cooling reduced with decreasing the heating-cooling rates from 10 to 1 °C/min, suggesting that SISH molecules had enough time to develop a stable and thermally irreversible network. Overall, SISH can be regarded as an acceptable hydrocolloid for generating natural food components with intriguing functional and rheological qualities in the formulation of microstructured goods.

Rheological properties of dairy desserts: Effect of rice bran protein and fat content.

Rice bran protein (RBP) is an alternative plant protein that can be used in a wide range of foods due to its unique functional, nutritional, and hypoallergenic properties. The interactions of RBP with other biopolymers have revealed its feasibility for application in dairy products such as whipped cream and dairy desserts. Therefore, the effects of RBP and fat content on the rheological properties of dairy desserts were investigated. The pH value was not influenced by protein, but the nonfat milk solid content was changed by fat and protein content. All the desserts showed thixotropic properties which were mainly related to the molecular disentanglement at high shear rates. By increasing fat like RBP, the apparent viscosity (ηa ) was increased. Rheological parameters such as n value, thixotropic index, storage (G'), and loss moduli (G'') were increased by RBP. Moreover, the dairy desserts containing RBP and whole milk presented generally higher G', G'', complex modulus, and complex viscosity values, and lower tan δ values. The RBP enriched samples also had a higher hardness and gumminess. Syneresis was decreased by RBP, which was related to the formation of ordered mesh-like structures which enabled the entrapment of more water. There was a positive correlation between the rheological, textural, and physical properties of the dessert with added RBP, and therefore dairy dessert attributes can be improved along with fat reduction. However, a sensory evaluation is needed to unravel the acceptability rate of RBP in fat reduction from the view point of consumers. PRACTICAL APPLICATION: Rice bran protein (RBP) has nutritional and hypoallergenic properties which enable it to apply to many products such as dairy desserts. One of the main concerns in dairy technology is the growing interest in low-fat products due to health problems. RBP showed unique properties which makes the creamy behavior. The rheological results have elucidated the creaminess associated with RBP and can assist in the proper simulation of mouthfeel.

Effect of inulin/kefiran mixture on the rheological and structural properties of mozzarella cheese.

The relationships between chemical, textural, rheological and microstructural properties of low fat mozzarella cheese incorporated with different ratios of inulin/kefiran mixture were studied. By increasing inulin content, the protein and moisture content was increased and as a result, the meltability was reduced. Although, textural properties of low-fat mozzarella was completely influenced by inulin incorporation and hardness was increased, but the lower springiness and higher cohesiveness of cheese was achieved at high level of inulin which may be related to the increase in moisture and protein. Rheological properties of low-fat mozzarella cheese confirmed its shear-thinning behavior in which the G' value was more than G″. Mechanical properties of cheese showed that inulin incorporation into cheese did not significantly change the rheological properties of the cheese matrix. Consequently, the formation of a more rigid and cross-linked protein structure which is less plasticized achieved at high inulin incorporation through keeping more water and protein and less fat content. SEM results indicated the sponge honeycomb structure of mozzarella cheese which clearly confirmed the textural and rheological properties and there was an interrelationship among chemical, textural, rheological and microstructural properties of low-fat mozzarella cheese incorporated at different ratios of inulin.

Effect of basil seed gum and κ-carrageenan on the rheological, textural, and structural properties of whipped cream.

BACKGROUND: Basil seed gum (BSG) is a novel polysaccharide that has been found wide application in the food industry. It can be used in whipped cream due to its thickening and emulsifying properties. The effect of BSG and κ-carrageenan on the structure-rheology relationships of whipped cream was evaluated. RESULTS: The viscosity of cream containing BSG was higher than that of carrageenan. Basil seed gum resulted in a strong capacity to improve the viscosity of the cream. Rheological results showed the low-frequency dependence of the elastic modulus was improved by BSG, which had a strong effect on the rigidity of the emulsion. The fracture strain of the creams containing BSG or κ-carrageenan was between the normal cream and acidified caseinate stabilized emulsion foam. It was found that the protein segments of BSG could be adsorbed at the oil-water interface, resulting in the formation of a pseudo-gel network, which creates a stronger molecular protein network in the whipped cream. Microstructure study revealed that whipped cream containing κ-carrageenan exhibited some flocculation, which could be caused by non-adsorbed polysaccharides or proteins. In contrast, cream containing BSGshowed more voids, which have considerably decreased by fat content and enhance the foam structure. CONCLUSION: As a result, synergistic interactions between proteins and polysaccharides (BSG and κ-carrageenan) could promote the development of a cross-linked network. Indeed, due to its high levels of hydrophilicity, BSG absorbs water, acts as a thickening agent, and competes against caseinate at the interfaces and is incorporated into whipped cream to provide a more desirable physical structure for the product. © 2021 Society of Chemical Industry.

Impact of ultrasound processing parameters on physical characteristics of lycopene emulsion.

Using ultrasound technology for obtaining O/W lycopene emulsions needs analyzing the parameters for the enhanced application. To this end, O/W lycopene emulsions (30:70) were processed using ultrasound with powers of 240 W and 360 W in 5, 10, and 15 min. Afterward, the poly dispersity index, droplet size, ζ-potential, turbidity, phase separation, lycopene concentration, rheological behavior, surface tension, and morphology of emulsions was investigated. The experimental results showed good emulsifying characteristics with respect to droplet size and ζ-potential. If the mean values of the droplet size were significantly reduced and the ζ-potential increased. The ultrasound application had a significant impact on emulsion stability with no phase separation and significantly high lycopene retention. Ultrasound reduced the apparent viscosity by reducing the particle size due to the energy supplied to the system. The final emulsion that was treated at 360 W, and 2160 J/cm3 in 10 min, presented enhanced technological properties appropriate for food products.

Effect of microbial exopolysaccharide on wheat bran sourdough: Rheological, thermal and microstructural characteristics.

Rheological, thermal and microstructural properties of wheat bran sourdough (WBS) containing different levels of microbial exopolysaccharide (EPS) extracted from Lactobacillus plantarum were investigated. All sourdough samples showed pseudoplastic behavior and the highest apparent viscosity was achieved at 1.5% EPS. The values of consistency coefficient of 1 and 2.5% EPS were significantly lower than for the dough without EPS. Increasing EPS in WBS produced a decrease in the storage, loss, and complex moduli of the sourdough, except that made with 1.5% EPS. This can be attributed to the microbial EPS structure and its ability to bind with water. It can be concluded, due to high hygroscopicity of EPS, WBS containing EPS had a lower access to water and other dough constituents. Thermal and microstructural results showed that EPS strongly modified starch gelatinization by prohibiting water access to amorphous parts of the granules and stabilized crystalline regions of starch causing an increase of end set temperature.

Structure-rheology relationships of composite gels: Alginate and Basil seed gum/guar gum.

Structure-rheology relationship of binary composite gel (BCG) systems of alginate/guar gum and basil seed gum/guar gum at ratio 2:1 at different Ca2+ levels (2-10%) were evaluated. The highest value of structural strength was obtained at 2 % of Ca2+, which can be attributed to its stronger network as assessed by rheological experiments. Mechanical spectra of the alginate/guar gels explained pseudoplastic behavior with a highly interconnected elastic gel structure. The mechanical strength as well as other textural properties of the alginate and basil seed gum network was functions of its stoichiometry with calcium ions. Whereas alginate/guar gels showed an elongated globular denser structure as determined by SEM, the BSG/guar gels showed a rigid cubic as the pieces of a puzzle, presenting a softer and weaker gel structure. The alginate/guar gels showed less porosity without syneresis or shrinkage during storage as supported by its high elasticity and rigidity.

Optimization of textural characteristics of restructured pimiento strips by response surface methodology.

In this study, the effect of guar gum (0.5%-1% w/w), sodium alginate (1%-2% w/w), and calcium chloride (2%-8% w/w) on textural properties of restructuring pimiento strips (RPS) was investigated. The gums were added to the pimiento strip formula, and different quality attributes including rupture force, energy to fracture, hardness, adhesiveness, cohesiveness, springiness, and chewiness were determined. Based on the textural properties of RPS, it was optimized by response surface methodology. All the textural properties of RPS were found to be significantly affected by alteration in guar gum, sodium alginate, and calcium chloride. The regression models for product's response like rupture force and energy to fracture were highly significant. Results showed that restructured pimiento strip formula containing guar gum 1% w/w along with sodium alginate 2% w/w and 8% calcium chloride improved the textural and tensile properties. According to the RSM results on the textural properties of RPS, it is feasible to achieve the high elasticity and rigidity of pimiento strips as well as obtain the ability to tolerate thermal and mechanical stresses with appreciable textural integrity during processing such as pasteurization that would be investigated in another work.

Development of vanillin/ß-cyclodexterin inclusion microcapsules using flax seed gum-rice bran protein complex coacervates.

Encapsulation of vanillin through ß-cyclodexterin inclusion complex coacervates (ß-CD-IC) was developed to achieve higher thermal stability and controlled release of vanillin. The effect of protein to polysaccharide (Pr:Ps) ratio and core (Vanillin/ß-CD-IC) to wall (coacervate) ratio on the vanillin encapsulation as well as thermal, microstructural and physical characteristics of microcapsules were investigated. Microcapsules had particle size ranging from 0.75 to 4.5 µm with negative surface charge and narrow size distribution. Although particle size and encapsulation efficiency were increased by increasing the Pr:Ps ratio and core to wall ratio, the zeta-potential decreased. Vanillin/ß-cyclodexterin loaded microcapsules had the maximum encapsulation efficiency about 85% at core to wall ratio of 1:3 and Pr:Ps ratio of 9:1. Structural studies by Fourier-transform infrared spectroscopy (FTIR) indicated the entrapment of encapsulant and X-Ray diffraction data and scanning electron microscopy (SEM) images showed that microcapsules have amorphous structure with soft surface. Furthermore, FTIR results indicated the formation of vanillin/ß-cyclodextrin inclusion is the result of chemical interactions, but physical interaction between core and shell leads to encapsulate vanillin/ß-cyclodextrin inclusion in rice bran protein-flaxseed gum (RBP-FG) coacervates. Microencapsulation increased the vanillin thermostability and its shelf life. Therefore, it is possible to increase thermal stability of vanillin against environmental conditions.

Microstructure and chemorheological behavior of whipped cream as affected by rice bran protein addition.

The effect of rice bran protein (RBP) isolate addition on the rheological and structural properties of commercial whipped cream with 25% and 35% fat was investigated. Results showed that increasing the fat content from 25% to 35% leads to an increase in the elastic modulus. Furthermore, by increasing the amount of RBP from 1% to 3% in both creams, significant increase occurred in the complex modulus. As the fat content increased from 25% to 35%, the slope of flow behavior was increased, which revealed more thinning behavior and pseudoplasticity index of cream. The cream containing 35% fat and 3% RBP had also shown the low index (n = 0.298) which confirmed the firmer structure of the cream. The maximum consistency index (k) obtained was 9.41 for the cream with 35% fat and 3% RBP, which approved its strong foam structure. In general, according to our results it is obvious that whipped cream with the highest amount of fat and the lowest value of protein can lead to maximum stability of the whipping cream. Among the samples, the lowest stiffness was observed in cream of 35% fat, containing 3% rice bran protein. However, cream containing 35% fat and 1% RBP had convenient overrun and good stability. The microstructural results showed that the cream structure has relatively large globular aggregates in network and develops large pores, which permit to retain sufficient water/air. By increasing the fat content of cream from 25% to 35%, the voids and spaces in the cream were significantly decreased and the pores become less which improve the foam structure. Therefore, it can be concluded the cream with more fat has the more overrun and stability. In general, it is possible to improve the foam structure of cream by substituting fat by RBP.

Textural, mechanical, and microstructural properties of restructured pimiento alginate-guar gels.

Textural, mechanical, microstructural, and thermal properties of reconstituted pimiento alginate-guar gels subjected to thermal and mechanical stresses during pasteurization process were investigated. Alginate-guar gelling system at ratio 2:1 at different calcium chloride concentrations (2-8%) and varying acid conditions including citric and lactic acid 1% were evaluated. Textural profile analysis parameters viz. hardness, springiness, gumminess, cohesiveness, adhesiveness as well as mechanical properties, structural, thermal, and morphological characteristics of pimiento strips were examined. Gel strength and elasticity of pimiento strips were increased at higher calcium levels. Fracturability was decreased clearly revealed the gel system, regain its strength in spite of high pulp content (25%) and can maintain its own structure. Increase in hardness and reduction in springiness showed loss of elasticity, which may be attributed to the gel shrinkage during thermal processing, making it more compact and dense. Therefore, the restructured pimiento strips were completely thermo stable at pasteurization temperature. By increasing alginate and calcium level in the pimiento strip, glass transition temperature was reduced from 112 to 98°C. Fourier transform infrared spectroscopy studies confirmed that the gel network structure at acidic conditions was stable and acid type did not has significant effect on the chemical interactions. The microstructural results showed ellipsoidal and compact structure in which can be an evidence of high elasticity and rigidity of pimiento gels. These results completely approved the high elasticity and rigidity of the pimiento strips and their ability to sustain successfully thermal and mechanical stresses with appreciable textural integrity during processing such as pasteurization. PRACTICAL APPLICATIONS: Restructured pimiento strip for stuffing into cocktail olives is a challenging problem in binary composite hydrogels of alginate and guar gum. The strips should be designed to be strong enough to handle mechanically and cut easily without tearing. Furthermore, it had to withstand to pasteurization process and be flexible to bend like a hairpin into the pit hole of olive. In addition, it also had low syneresis and shrinkage that the strips not fall out of the olive hole during storage. In the view point of marketing and nutritional aspects, it is more advantageous to develop a restructured fruit gel systems several times higher than the limiting 10% pulp because of its weak structure. Therefore, alginate-gel systems containing 25% pimiento pulp were evaluated at different levels of calcium chloride and thermal processing.

Effect of high-amylose corn starch addition on canning of yellow alkaline noodle composed of wheat flour and microbial transglutaminase: Optimization by RSM.

Mixture experiment was applied to optimize the canned cross-linked high-amylose starch yellow alkaline noodle formula. Processing factors of canned yellow alkaline noodle (YAN) cross-linked by MTGase at different levels of Hylon VII were surveyed. The factors were wheat flour, Hylon VII starch (HAS) as a high-amylose starch, and water in the mixture to achieve reduction in cooking loss, water uptake, swelling index, and thickness. Due to the effect of retort processing on YAN, pH, color, and texture were also examined. Analysis of variance showed that the linear mixture had a significant effect on the noodle properties. Optimum conditions were as follows: wheat flour of 75 g, HAS of 15 g, and water 67 ml. Results showed the suitable effect of Hylon in improving texture of canned YAN as well as high gel strength, neutral pH, lowest cooking loss, water uptake, swelling index, and color after retort processing. Therefore, high-amylose decreased swelling of starch, cooking yield, and improved hardness which obtain a strong gel and better stability in canned noodle. The pH fall and the attainment of yellow color in the YAN containing Hylon can be explained by the availability of two important amino acids, lysine and glutamine which were involved in both cross-linking reactions. The synergistic effect of low amount of flour and Hylon produced more tensile and hardness properties in canned noodle. Overall, the canned YAN prepared by adding Hylon developed the stronger gel which can withstand at high thermal retort processing and finally improve the shelf life of the final product.

Rheological and structural properties of enzyme-induced gelation of milk proteins by ficin and Polyporus badius.

The rheological and microstructural characteristics of ewes' milk curd obtained by coagulating with milk-clotting enzymes, including ficin extract and Polyporus badius were evaluated. The gelation of milk was examined by small amplitude oscillatory shear measurements (SAOS). Different concentrations of ficin and P. badius extracts (1, 3, and 5%) were utilized to coagulate milk proteins. The ewes' samples containing ficin and mushroom enzymes were heated from 25 to 45°C at a heating rate 1°C/min and kept for 30 min. Then, the curds were cooled down to 25°C with the same heating rate. The ficin extract could induce stronger gels at 45°C and 5% ficin. Similar results were also found for 5% P. badius extract and incubation at 45°C. However, P.badius gels achieved a network with more viscous characteristics and had a softer texture than ficin gels. Therefore, it may be concluded the induced gels with mushroom had higher moisture and lower protein contents, which related to the high proteolytic activity of P. badius. The microstructure survey showed that the mushroom-induced gel had a more compact structure. By increasing enzyme concentration, both gels showed a coarser and more compact protein network. Whereas, the P. badius gels had more fusions and folds which indicate the greater proteolysis occurred during gelation and there was greater breakdown of protein. Our findings suggest the application of ficin and P. badius enzymes to develop a novel procedure to coagulate milk proteins and providing new structures in food systems.

Rheological characteristics of binary composite gels of wheat flour and high amylose corn starch.

The effect of addition of high amylose corn starch (Hylon VII or H) to wheat flour (WF) on the mechanical properties of the resulting binary composite gels (BCG) under small and large deformations was evaluated. To this end, the composite gels at different ratios of WF/H including 95:5, 90:10, and 85:15 were tested under a linear viscoelastic regime (LVE) in oscillatory angular frequency and a texture profile analysis in compression mode. However, the gel firmness was increased by Hylon VII addition, but the springiness was reduced. Since the adhesiveness and cohesiveness were not significantly different, no dilution effect was observed for the samples. Furthermore, the dominance of G' than G″ over the range of LVE and high fracture stress at high level of Hylon VII confirmed the high gel strength which can be attributed to the retrogradation of amylose and reduction of amylopectin from WF. The less frequency dependency of BCG revealed the solid-like response and strong gels structures with more elastic network. High value of α revealed a lower number of interactions within the gel network structures. Consequently, due to the high gel strength of BCG of WF/H, it can be exploited at high thermal operations such as retort processing as well as it can be utilized for dysphagia therapy due to the special textural parameters. PRACTICAL APPLICATIONS: Small and large deformation properties can provide profound insights toward the gel structure. The former gets knowledge about dynamic rheology and the latter gives the textural properties of the gel matrices. Since, achieving the desired texture of foods has a chief impact on the target consumers, and chewing and swallowing disorders such as dysphagia are common problems in older people, more effort is needed to modify the texture of food with a soft structure. On the contrary, supplying a more gel strength network, which can withstand at high thermal processing and not collapse, is so vital. Therefore, the current work was accomplished to provide some knowledge about the binary composite gel of WF and Hylon VII starch such as the gel strength, fracture stress, fracture strain and material stiffness which enables us to evaluate the nature of starch gels for further applications such as drug delivery systems, elderly diet and further processes.

Application of whey protein-pectin nano-complex carriers for loading of lactoferrin.

Our aim was to entrap lactoferrin (LF) in complex nano-particles of whey protein isolate (WPI)-high methoxyl pectin (HMP) with the ratios of 2:1, 1:1, and 1:2 through acidification at pH values of 3, 3.5, and 4. The zeta-potential, size, sedimentable-complex yield, LF content, encapsulation efficiency, SEM, AFM, FTIR, and DSC of nano-particles were investigated. Our results revealed that almost all analyzed parameters of the final nano-particles were related to preparation pH value, WPI/HMP ratios, and acidification methods In both methods of pre- and post-acidification, the zeta potential was decreased via decreasing of pH from 4 to 3 and particle size was increased at higher HMP ratios to WPI. In general, the pre-blending acidification provided a larger mass of complexes compared with post-blending counterparts. Also, the nano-particles produced by WPI/HMP with the ratio of 2:1 at pH=3.5 had the smallest sizes. The highest LF content of the complexes as well as the optimal entrapment efficiency was observed at pH=3.5, in both methods of post and pre-blending. Finally, the pre-blending by a ratio of 2:1 for WPI/HMP was chosen as the optimal treatment for producing nano-particles containing LF. This was confirmed by SEM, AFM, FTIR, and DSC studies.

Physicochemical, functional, and nutritional characteristics of stabilized rice bran form tarom cultivar.

Extrusion is a multistep thermal process which has been utilized in a wide spectrum of food preparations. The effect of extrusion processing on the physicochemical, nutritional, and functional properties of Tarom cultivar rice bran was studied. However, the color of rice bran was improved by extrusion processing, but the protein content was reduced in the stabilized rice bran, which can be related to the denaturation of protein. Extrusion had also a reduction significant effect on the phytic acid as well as vitamin E in rice bran. However, the content of niacin, riboflavin, pantothenic acid, and folic acid remained unchanged, but the dietary fiber was enhanced which has beneficial health effect on human consumption. In comparison with unstabilized rice bran, water holding capacity was enhanced, but the oil absorption capacity was reduced. Foaming capacity and foaming stability of extruded rice bran was more than that of untreated rice bran, although they were less than that of rice bran protein concentrate/isolate. In general, the extrusion process improves some functional and nutritional properties of rice bran which are valuable to industrial applications and have potential as ingredient in food to improve consumer health.

Effects of high amylose corn starch and microbial transglutaminase on the textural and microstructural properties of wheat flour composite gels at high temperatures.

Textural and microstructural properties of composite gels (CGs), along with wheat flour and high amylose corn starch (Hylon VII) mixed with microbial transglutaminase (MTGase) at different levels and temperatures were investigated. The results showed by increasing Hylon starch content, the firmness increased and adhesiveness decreased. Indeed, high level of amylose and cross-linking formed by MTGase enhanced the gel elasticity and reduced adhesiveness. Moreover, MTGase had more effect on the firmness and provided more cross-linked intermolecular gel structures at high temperatures. By adding MTGase to the CG, the lowest peak viscosity and final viscosity were found for 15% of Hylon starch. As the more Hylon content in the CG, the more water solubility index was particularly obtained at high temperature. Scanning electron microscopy (SEM) results showed that MTGase and Hylon starch addition enhanced the structure. The differences in SEM of CG were reflected the pasting properties of the gels. Consequently, MTGase treated gels can withstand high temperature as well as maintain the overall structure of the samples gels. Therefore, the increment of Hylon to the CG gels supplied tighter, stronger, and denser protein network which were formed by MTGase cross-linking within the network of starch and proteins. PRACTICAL APPLICATIONS: Although, transglutaminase was practically used in the production of noodles and pasta in Japan, but there is little academic and industrial knowledge concerning its utilization in the pasta or noodles. Moreover, long shelf-life noodle/pasta products have become popular in the Japanese market and in the emergency conditions like as floods or earthquake, but they can be stored for at least 5 months by applying heat treatment at 95C. Here, high amylose corn starch as a resistant starch, wheat flour, and microbial transglutaminase (MTGase) were selected as the main components in the composite gel (CG) systems to elucidate the effects of MTGase and Hylon on the texture, microstructure, and pasting behavior of CGs at high temperatures to produce long-life noodle/pasta products (about 2 years) through retort processing.

The influence of temperature, sucrose and lactose on dilute solution properties of basil (Ocimumbasilicum) seed gum.

Hydrocolloid interactions with solvent/cosolutes play a vital role in the resolution of their functional properties. Basil seed gum (BSG) is a plant-derived hydrocolloid which has been found many applications in food formulations as stabilizer, emulsifier, thickener and gelling agents. Sucrose and lactose are the most effective sugars in textural and sensorial properties of bakery and dairy products which adding them to solutions containing hydrocolloids can be helpful to approach a proper formula. In this paper, the effect of temperature (25-65°C), sucrose (10, 20, 30 and 40%) and lactose (5, 10 and 15%) were investigated through some molecular parameters of BSG. Results revealed high flexible chain (665.35), intrinsic viscosity (11.38 dl/g) and hydrogel content (73%) of BSG, which may be attributed to some extent by its high molecular weight (1.73×106Da). The density and intrinsic viscosity of BSG were diminished by growing temperature from 25 to 55°C. Among five models, which were applied to estimate intrinsic viscosity, Higiro-2 was the most suitable model at varying temperatures and cosolutes concentrations. The sugars showed a significant effect on the molecular parameters of BSG such as swollen specific volume, shape function, hydration parameter, and coil dimensions. The sugars showed more impact on the [η] of BSG and its molecular parameters than that of temperature. However, lactose had a more prominent effect on the BSG dimensions than that of sucrose, which can be related to its molecular conformation and spatial orientation. It is feasible to make a proper formula by BSG and explain some phenomena in its applications in food and pharmaceutical systems.