جستجوی مقالات مرتبط با کلیدواژه « خمیر » در نشریات گروه « صنایع غذایی »

Increasing shelf-life and nutritional value of bakery products always are important. In this research, curcumin (CUR) loaded in nanogel-reinforced hydrogel (isolated soy protein (ISP)/Sodium alginate (SA) nanogel-based cress seed gum (CSG) hydrogel) was used to improve rheological characteristics of dough and technological and organoleptic properties of Barbari bread (traditional Iranian bread). The effects of nanogel-reinforced hydrogel (at 0, 5, and 10% levels (flour basis)) with and without CUR on Barbari bread quality were investigated. The rheological properties of dough were evaluated by farinograph and extensograph analysis. The results showed that water absorption, consistency, energy and extensibility of dough increased with addition of composite hydrogels, while degree of softening 10 min after beginning reduced. Addition of hydrogel increased specific volume, porosity and hardness of the bread. The crumb lightness of CUR-composite hydrogel increased (75.51±0.06) in compared to control (69.19±0.07). Presence of 10% hydrogel </strong>composite significantly increased (a*) parameter of crust (9.96±0.13) (P</em><0.05). The enthalpy and endothermic peak temperature reduced due to incorporation of 10% (w/w) CUR-composite in bread. The results showed the addition of 10% CUR-composite improved the organoleptic properties of the bread and its shelf life.

The effects of adding powdered leaves of Portulaca Oleracea</em> on the physicochemical properties of wheat flour dough were evaluated  with farinograph test. The amount of fat, protein and fiber was more in powdered leaves of Portulaca Oleracea</em>  than wheat flour. Farinograph test results show  an increase in water absorption, stability time and Farinograph quality number and a decrease in the Degree of Softening in dough with increasing replacement of powdered leaves of Portulaca Oleracea</em>(P< 0.05). Farinograph quality number with increasing in the percentage of powdered leaves of Portulaca Oleracea</em> to10% was decreased, but 15% powdered leaves of powdered leaves of Portulaca Oleracea</em> showed highest number Farinograph quality(P< 0.05). With increasing levels of powdered leaves of Portulaca Oleracea</em> decreased Degree of Softening in dough and created significant changes in dough development time(P< 0.05). Farinograph assessment of dough provided with powdered leaves of Portulaca Oleracea</em>, dough prepared with 10% leaf powder introduced as the best example in terms of the rheological properties.

Water plays a key role in dough formulation and bread quality. Particularly in gluten-free doughs containing hydrocolloids, water is important in regulating the solubility of the components, dough consistency and resulting bread texture and quality. Therefore, the texture and quality of gluten-free bread is strongly influenced by the selection of its ingredients, especially the amount of water. The purpose of this study was to investigate the effect of adding different amounts of water in 6 levels (80, 90, 100, 110, 120 and 130%) on the rheological properties of the dough (extrusion test and leavening properties), technological properties (volume, baking loss, porosity, firmness and shelf-life) and the sensory properties of gluten-free bread. Rheology results showed that by increasing the amount of water from 80 to 130%, the consistency of the dough decreased and the leavening ability of the dough was improved. An increase in the amount of water up to 130% increased the amount of bread specific volume from 1.86 to 3.14 mL/g. In terms crumb structure, an increase in the amount of water up to 130% increased crumb porosity. Bread firmness (24 h after baking) decreased from 0.325 N to 0.273 N by increasing the amount of water. The results showed that samples containing high amounts of water (120 and 130%) were more susceptible to mold growth than those with low water content (80 and 90%). Sensory results showed that increasing the amount of water from 80 to 130% improved sensory characteristics such as bread volume, porosity and firmness, and increased the overall acceptance of samples. Overall, samples containing 120 and 130% water in formulation, received the highest overall acceptance scores.

Celiac disease is a common autoimmune diseases caused by gluten protein.The only effective remediation is a gluten-free diet. So, production of gluten-free is one of priorities in food industry, for help to these individuals.In this study, te effect of malted millet flour (0, 10, 20 and 30 %) and xanthan gum (0,0.1 and 0.2%) on physical propertiesh of gluten free batter evaluated and to outrance,cakes of it, from viewpoint texture properties analysised. The results showed that addition of malt millet flour in formulation, because of high enzyme activity and the absence of gluten protein to To produced a weak batter that in whichincrease levels of malted millet flour, Leading to a significantly reduction in viscosity andincrease specific gravity of batter compared with the control sample. But xanthan gum with confined water and increasing the capacity to it, Significantly improved the physical parameters of batter. About textural properties observed that absence of gluten network, significantly reduction textural coherencess and resilience to be created and interaction whit xanthan gum significantly increased this parameters.According to the results, Sample containing 10% malted millet flour and0.2% xanthan gum was reported as an optimum combination in the formulation of gluten-free cake.

Converting milk into milk powder increases its shelf life up to almost 1 year, without substantial loss of quality, even at ambient temperatures. Dairy powder is frequently used because of convenience in applications for transportation, handling, processing, and ease of product formulations. Functional properties of milk powder are important due to its wide range of applications, especially in bakery products requiring desirable texture and moisture content. These functional properties include emulsification, foaming, water absorption, viscosity, gelation, and heat stability. Fresh milk and milk products such as condensed or dried milk which have not been exposed to sufficient heat treatment are not suitable for good quality bakery products as properly heated milk, mainly due to the destruction of proteolytic enzymes by heat, denaturation and coagulation of the proteins, changes in the colloidal properties of the salt and alterations in the oxidation-reduction systems. Kirk (1971) has outlined a list of functional contributions provided by skim milk powder (SMP) in various bakery food products, such as increased absorption, buffering value, lactose color reaction, tenderizing effect, improved body and resilience of crumb. This is in agreement with the results showed by Pyler who added SMP to bread and cake affected. Pyler noted the advantages of lactose in food systems. Lactose mostly affect relative sweetness, browning reaction, protein stabilizing properties, alteration of crystallization patterns, flavor accentuation, selective fermentation, and has nutritional value.
Yazdi cake was produced using baking wheat flour (from Golha factory), sugar (sucrose), hydrogenated vegetable shortening, baking powder, and baking soda. Eggs were bought the day before baking and refrigerated at 4°C. The dough was prepared in ratio of 30 % oil, 46 % sugar, 50 % water, 11.7 % eggs, 4 % baking powder and 1 % baking soda rather than flour. For improvements of flavor and taste, an equal value of vanilla was added to the whole dough formulations. Skim milk powder containing 1.5 % fat, 3-4 % moisture has bought from Pegah factory. 25 and 50 percent of skim milk powder was also added to the dough. Dough was prepared based on the method of double mixture steps and was baked at 180°C in oven for 30 min. Samples were vacuumed and kept at ambient temperature for further experiments
Result and The differences in specific volume and consistency of the dough values were found to be significant (p>0.01). According to Baeva studies, there is an inverse relationship between specific gravity and the entry air bubbles in the dough, so the sample with 50% had the lowest specific volume. The consistency of the dough increased significantly by increasing in SMP content (P

Sourdough is a complex biological system, consisting of such components as cereal carbohydrates and proteins, lactic acid bacteria and yeasts and different enzymes from which each of these taste, flavor and shelf life of bread can be improved with optimal use of sourdough. The aim of this study was to determine the effect of spray dried sourdough addition on gluten development through studying dough microstructure using epi-flurescence microscope. Therefore, the traditional dough was prepared by adding 15% sourdough powders containing three lactobacillus strains, which were previously isolated from Iranian traditional sourdoughs (Lactobacillus plantarum, Lactobacillus curvatus and Lactobacillus Paralimentarius), to the dough. According to microscopic observation with simultaneous staining of dough samples with rhodamine 1% and FITC 0.1%, it was showed that samples had continuous gluten network layer and protein network was not destroyed. Which can be attributed to the insufficient amount of microorganisms, low resting after preparing the dough and insufficient activity of microorganisms.

Ozone is triple form of oxygen which in addition to antimicrobial and disinfectant nature has several properties and applications in the food industry such as improvement of flour quality because of the chlorination replacement. In this study¡ the effect of ozonation on the microbial population of flour and rheological properties of dough (water absorption¡ dough development time¡ stability¡ mixing tolerance index¡ valorimeter index¡ resistance to extension and extensibility) were investigated in 2×4 factorial experiment with two levels of the flour type (strong and weak) and four levels of ozonation period (0¡ 15¡ 30 and 45 minutes) in Completely Randomized experimental Design (CRD) with replications. Results showed that ozone as an oxidizing agent had not significant effect (p

Bread is traditional food generally prepared from wheat flour. Flat breads are the oldest and well-known kinds of bread worldwide. The main wheat component responsible for bread quality is gluten, which is an essential structure-binding protein. Although important, this protein can cause health problems in predisposed individuals with celiac disease. Consequently hydrocolloids are used to substitute for gluten and mimic the viscoelastic properties of it. In order to consider the influence of xanthann and CMC on dough rheological properties, they used in 0.5,1,1.5% to evaluate the influence of each level separately and in 0.5, 1% (flour basis) for incorporative effects of them. In farinogragh measuring, treatment4 (1.5%Xanthan) and treatment11 (1%CMC,1%Xanthan) resulted in highest water absorption. Increasing the level of xanthan led to increasing water absorption significantly in comparison to CMC. Xanthan and CMC decrease and increased dough time development respectively. Addition of xanthan resulted in a farinogram which resembled that of a standard farinogram obtained by wheat flour. In dough dynamic measuring, hydrocolloids caused higher viscoelastic modulus and increasing the level of them made them greater. The highest G' was in treatment4, between used separate gum treatments. tanδ in treatments contain CMC was more than treatments contain xanthan and it was the most in treatment7(1.5%CMC). G' and G" in treatments contain incorporative gums was more than treatments contain separate gums. In these treatments, Xanthan decrease the tanδ resulted in treatments including CMC seperately. Treatment11 has higher dynamic modulus and tanδ than treatment4. In all cases xanyhan had affect on increasing water adsorption, decreasing dough time development, elastic modulus acceleration and decreasing tanδ.

Barbari bread is one of the most widely used breads in Iran which has high loss. Consequently, finding a solution for quality improvement of this type of bread seems to be necessary. One way to achieve this goal is optimizing of flour enzymatic activity by using enzyme sources such as barley malt. The purpose of this research was to optimizing the percentage of barley malt flour in order to improve the quality of Barbari bread. To this purpose, barley malt flour was added to flour at concentrations of 0.5, 1, 2 and 4% based on flour weight and five bread samples including control sample (without barley malt) and four samples containing mentioned added amount of barley malt were prepared. In the next step, some experiments were fulfilled to measure the quality of bread samples. By adding barley malt flour up to 1% on flour weight, width/height ratio, oven spring, water absorption, dough development time and Farinograph quality number increased; whereas the falling number and crumb hardness of fresh bread was decreased with the increasing amount of barley malt. Microstructure of bread which were studied by SEM, showed that barley malt up to 1%, creating some type of fluidity in cell walls. Sensory evaluation showed that the quality of the sample containing 4% of barley malt flour was lower than the control sample because of its malty taste and sticky crumb. As a result of this research, the sample with 1% of barley malt flour was recognized as the best bread sample.

Purslane and flaxseed are rich sources of alpha-lineoic acid (omega-3)، lignans، dietary fibre and various anti-oxidants. Health benefit of such components in prevention of certain diseases is the major reason for fortification of functional food products with these ingredients. In this study، effect of incorporating an equal (50:50) mixture of flaxseed andpurslane powders on physicochemical characteristics of flour and dough rheological properties was investigated. Addition of 5، 10، 15 and 20 %w/w of the mixture led to an increase in total protein and crude fibre contents of the supplemented flours، while wet gluten and Zeleny number were decreased. Addition of 5% flaxseed-purslane powder increased Farinograph water absorption، whereas above that level، water absorption of flour was not significantly (p<0. 05) influenced. All levels of incorporation (except 20%) significantly increased Farinograph quality number. Farinograph results showed shorter stability time، higher softening degree for the supplemented flours compared to those of control flour. Extensigraph experiments revealed a significant increase in maximum resistance to extension (Rmax) for supplemented flours. Nevertheless، dough extensibility (E) was declined.

Inulin is a fat – replacer added in bakery products to increase the fiber and decrease the calorie content. In this research, effect of the replacement with Inulin was studied. Physical properties of batter such as specific volume, density and rheological properties of batter such as viscosity were evaluated. Results showed no significant differences in the density and specific volume between control batter and batter prepared with 20% fat-replacer level. Increasing Inulin level in the batter showed there were significant differences in the physical and rheological properties. Batter prepared with 20% fat-replacer level showed lower viscosity than that of control. Evaluating the effect of inulin on the textural attributes showed cake prepared with 20% fat – replacer level was as firm as the control sample. Increasing the level of replacer showed the hardest texture. The hardest texture was observed in the cake prepared with 60% fatreplacer.

Kefiran is an exopolysaccharide which is produced mainly by lactic acid bacteria and fungi in kefir grains during growth. In this study، kefiran was added at levels of 1، 2 and 3% w/w (flour basis) to wheat flour and its effects on physicochemical characteristics of wheat and flour and rheological properties of dough was investigated. Physicochemical properties of wheat and its flour were analyzed by inframatic and the rheological of dough by farinograph and extensograph instruments. The results of physicochemical properties of the tests wheat and its flour showed that wheat had hectoliter and thousand seed weight، water absorption، flour yield and falling number higher than standards، whereas its hardness، wet gluten، moisture and protein content along with zeleny index and SDS-sedimentation height were higher than those of standards. Results of farinograph evaluation of dough showed that addition of kefiran significantly (P<0. 05) increased dough water absorption، dough development time، departure time and valorimeter value، while decreased mixing tolerance index and dough degree of softening after 10 and 20 minutes. Nevertheless، dough stability did not change significantly (P<0. 05). The results of extensograph showed that kefiran significantly (P<0. 05) increased resistance-to-extension and energy for extension in over the time while، dough extensibility was significantly (P<0. 05) decreased due to increasing levels of kefiran. It was concluded even though kefiran had no significantly effect on dough stability، could significantly increase resistance-to-extension and decreased mixing tolerance index and dough degree of softening after 10 and 20 minutes. Therefore، kefiran can be used to improve rheological properties of weak dough and its processing conditions.

In this study three different methods of batter making including sugar-batter, flour-batter and all-in processes were studied. The effect of mixing method on batter physicochemical properties such as specific gravity and consistency, quality properties of product such as moisture, water activity, apparent density, volume, specific volume, symmetry and uniformity, texture, color and also sensory properties 1 and 5 days after production was evaluated. Results showed that all-in method leads to higher specific gravity and consistency values in batter and a darker color compared to other methods. Samples prepared by sugar-batter method had higher (P<0.05) water activity, volume and symmetry values. Samples produced by sugar-batter and flour-batter methods had similar moisture content, whereas all-in method produced cakes with a lower moisture content (P<0.05). Instrumental measurement of texture showed that cakes produced by sugar-batter method had the softest (P<0.05) texture at the first day of evaluation. There were no significant differences between cakes prepared by flour-batter and all-in methods. In the 10th day of texture evaluation sugar-batter cakes showed the softest texture; but flour-batter cakes had the harder texture in comparison with sugar-batter cakes. Samples prepared by all-in-one method had the hardest texture. There were no significant differences between three methods in apparent density, specific volume and uniformity of cakes. Sensory evaluation showed that sugar batter cakes gave the most acceptability values.

Purslane seeds are rich sources of alpha-lineoic acid (omega-3) in all green plans that ever examined. This plant also contains substantial amounts of lignans، dietary fibre and natural anti-oxidants such as tocopherols. Health benefit of such components in prevention of certain diseases is the major reason for fortification of functional food products with purslane. In this study، effect of the addition of purslane powder on physicochemical (particle size distribution، protein، fiber، wet gluten and zeleny number) properties of wheat flour as well as rheological properties (in farinograph and extensograph) of the corresponding doughs was investigated. Purslane seeds powder was used to replace 50، 10، 150 and 200 g kg-¹ of wheat flour. Total protein and crude fiber contents of supplemented flours increased while wet gluten content and zeleny number of flour blends decreased as the amount of purslane seeds powder increased. Farinograph results showed lower water absorption، farinograph quality number، shorter stability time a higher softening degree for purslane supplemented flours compared to those of control flour. This indicates the weakening of dough rheological properties upon the addition of purslane seeds powder. Extensograph experiments revealed a significant increase in maximum resistance to extension (Rmax) for supplemented flours، except for 5 and 15% supplementation. Dough extensibility and extension energy were declined for all treatments، except for 5% supplemented flour.

Some hydrocolloids are capable of improving the quality of bread and retarding staling. With the aim of improving the quality and delaying the staling of pan bread pectin and cross-linked pectin were added at 0، 0. 5، 0. 75 and 1% (w/w، flour basis) to the bread recipe and effected of these components on the properties of dough and bread were studied. The results showed that addition of pectin and cross-linked pectin had positive effects on water absorption of the flour. Determination of the farinograph parameters of the dough showed that addition of these components could decrease the dough arrival time، while increased the dough softening، however، other farinograph parameters remained unchanged. The control sample had the hardest texture while the sample containing 1% pectin and 0. 5% cross-linked pectin had the softest texture. The highest volume was observed for the bread containing 0. 5% pectin. Determination of the crust color showed no significant differences between breads containing either pectin or cross-linked pectin، while the control had the lightest crumb color. In general، addition of pectin and cross-linked pectin could improve the quality of bread and delay its staling. However، pectin had more positive effects on bread quality compared to the cross-linked pectin.

Natural fermentation based on the inherent flour microflora is an ancient sourdough making process. Nowadays، selected starter cultures are used to provide quality consistency in the sourdough making process. In this study، the effects of two-stage or sponge-and-dough process using L. reuteri starter culture versus single-stage or straight dough processes on the properties of resulting dough and bread were assessed. In general، the sponge-and dough process led to lower pH and higher total titrable acidity in the resulting dough. The straight dough process resulted in breads with significantly higher pH and lower total titrable acidity than those of sponge-and-dough process. Loaf volume and bread height was increased when straight dough method was applied. However، bread moisture content remained higher for sponge-and dough process. There was no significant difference between sensory scores of breads prepared from both dough making processes. Nevertheless، sponge-and-dough process resulted in softer breads with low staling rate. Moreover، sponge-and-dough breads showed better shelf life with delayed mold growth.

Gluten strength is the major factor affecting mixing characteristics، extensibility، elasticity، and stability of dough. Wheat bug injects a protease enzyme into immature wheat kernels while feeding. This enzyme remains in flour made from bug damaged wheat and، in dough، digests gluten to produce slack، sticky dough and poor quality bread. The effect of sonication conditions on dough rheology affected by protease inactivation in flour made from bug damaged wheat were investigated. Results showed that sonication with 70% amplitude in 5 min maintained rheological properties of dough. Sonication improved water absorbtion، dough stability، extensibility، and resistance to extension. Bread baked from bug damaged flour treated by sonication had better color، texture، specific volume، and appearance.

The effect of flour hydration on the rheological characteristics of bread dough was investigated. For this purpose، hydrated zero-developed (zero mechanical energy developed; ZD) doughs، which hydrated out side of the mixer were used. The influence of hydration temperature (5 and 25 °C) and time (1. 5، 4 and 24 h) on hydration ability of doughs was investigated. Farinograph and Extensigraph experiments were used to study the behavior of hydrated doughs upon different hydration treatments. Results indicated that increasing hydration time and temperature led to an increase in hydration performance، thus hydration phase in Farinograms was decreased and finally disappeared. Comparing doughs prepared from ZD doughs versus those mixed from conventional flour-water mixtures showed that reduction in hydration phase (arrival time) in ZD doughs، especially upon hydration at 25 °C for 24 h، arrival time was totally disappeared. However، doughs prepared with ZD-dough had lower Farinograph «stability» and higher «degree of softening» values compared to those mixed from flour-water mixtures. Only hydration at 25 °C for 24 h gave suitable doughs for Extensigraph experiments. Evaluation of Extensigram of such dough compared with doughs mixed from flour-water mixer showed better rheological performance (higher Rmax، energy to extension and Ratio values).

The effect of three hydrocolloids with different chemical structure and from different sources on the rheological properties of wheat flour dough، fresh baguette bread quality and its influence on bread staling were studied. The influence of the selected hydrocolloids (Guar، Pectin and Xanthan gum) on rheological behavior of dough was tested by using extensograph and farinograph. Rheological characteristics of wheat flour doughs were modified to different extent by hydrocolloids of varying chemical structure. The greatest effects، but not the better ones، at dough level were promoted by xanthan followed by guar، these hydrocolloids strengthen the wheat flour dough. Hardness and sensory characteristics of bread after storing for 24 and 48 h. Hydrocolloids affected in different extent to stored bread. Although different improvements were observed associated to specific hydrocolloid، guar was the hydrocolloid with an improvement effect on all the parameters tested، specific volume index and crumb hardness. In addition، during storage، guar gum showed an anti staling effect، reducing the crumb hardening.

Studying dough microstructure is considered as a useful and effective tool to understand the effect of different process parameters on dough and the final product characteristics. In this study, sample preparation and staining protocols were established to study the dough micro-structure with epi-fluorescence light microscope (EFLM). For this purpose, dough sample preparation and staining conditions with respect to the type of staining dye, solvent, dye concentration, staining time and the type of filter used for EFLM were studied. The results showed that sodium Fluorescein (1% w/v) and Rhodamine B (0.1% w/v) in 2-methoxyethanol solvent give the best staining results. The double staining technique used enabled us to simultaneously and successfully observe the starch granules and protein network in the dough. The resting time after the addition of the dye had an impact on the quality of microscopic images. Among different resting times investigated, 60 min time gave the best results. Among the different EFLM filters, the MWBV2 filter for 420 nm spectrum gave the best results. Using image processing software and the specialized plug-ins the quality of EFLM images was improved. When a suitable protocol and methodology was established, the microstructure of dough was studied under different mixing regimes (under-mixing, optimal mixing and over-mixing). Overall, the results indicated that EFLM can be successfully used for studying the dough microstructure and this technique gives comparable results to well-known CSLM technique.