Roya Nejatbakhsh; Sara Movahhed; Hossein Ahmadi Chenarbon
Abstract
Introduction: The quality of breads depends on the baking capability of flour, fermentation time, protein content, and type of additives. An economically important concern of the baking industry is delayingthe bread staling. In addition, the staling process changes outer and inner properties, scent, ...
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Introduction: The quality of breads depends on the baking capability of flour, fermentation time, protein content, and type of additives. An economically important concern of the baking industry is delayingthe bread staling. In addition, the staling process changes outer and inner properties, scent, flavor, and chewiness of breads, which in turn leads to staled or, in other words, non-fresh breads. The application of lactic sourdough and/or other techniques such as improved dough making, improved baking quality, packaging, and use of additives and improvers can be highly effective in delaying this process. One of the additives that improve the properties of baked products is the α-amylase enzyme. α- amylase can improve the elastic properties of the texture while delaying staling. This enzyme can also form useful sugars for yeasts and increase gas formation in dough, which in turn improves and increases the bread volume. Against this background, the current study analyzed the effects of sourdough and α-amylase on qualitative characteristics, physicochemical properties, staleness, size and sensory profile of the toast breads.
Materials and methods: The ingredients of the toast bread dough, i.e. 78% wheat flour (1 kg), sugare (1-2 w/w%), salt (1.8-2.2%), oil (3-6%), yeast (1.5-2%), α-amylase (0.01-0.03%), lactic sourdough (4 and 6% of wheat weight), were prepared and weighed to make the dough required for the baking process. The dough samples were spread and then rolled after an initial resting of 10-15 minutes. The rolls (approx. 580 g) were transferred to a cast. The dough samples were finally moved to the fermentation chamber at 35°C and 80% relative humidity for final fermentation and baking. Their analyzed using different physical, chemical, and sensory tests. A completely randomized design with three replications was used to analyze experimental data (except for staleness data of bread samples from sensory and instrumental tests which were analyzed using factorial experiment with a completely randomized design). Means were compared by Duncan's multiple-range test (α = 1%) in SPSS 16.
Results and discussion: According to the results, α-amylase and lactic sourdough caused an increase in bread’s MC compared to the control samples. In other words, starch hydrolysis by α-amylase created free water in the dough. Moreover, sourdough increased water absorption of wheat through mechanisms including production of exopolysaccharides and increased production of pentosans. The application of α-amylase and lactic sourdough also increased the ash content of the breads compared to the control samples because they increased the production of dextrins and synthesis of exopolysaccharides. It should be mentioned that these additives decreased the pH of breads compared to the control samples. This is because the sourdough bacteria produced lactic, acetic and other acids that acidified the medium and reduced the pH. This enzyme also produced metabolites like dextrins and increased the amount of fermented active ingredients, which further reduced the pH. The proteolytic activity of lactic bacteria of the acid in sourdough led to decomposition of proteins, particularly gluten, into amino acids. This also reduced the protein content and diluted the gluten in breads. The results showed that the lactic acid bacteria of the sourdough hydrolyzed the fat control of bread samples by their lipase and thus lowered the fat content in bread samples compared to the control. The fiber content of samples was higher than that in the control as a result of enzyme and sourdough application. This is due to the fact that fermentation increases the pentosan content and reduces their molecular size. It also increased solubility of insoluble fibers like beta-glucans. On the other hand, their application led to larger bread size than the control because α-amylase hydrolyzes the starch and breaks the amylose and amylopectin chains to convert them into disaccharide substrates. Accordingly, yeasts could grow better and produce more CO2 in the dough, increasing the bread size. The application of this enzyme and lactic sourdough gave a brighter appearance to toast bread samples whereas a* and b* were reduced. This is because the bread undergoes changes in its crust color during the baking process, which are mainly caused by maillard and caramelization reactions. It is worth noting that these additives reduced the staleness of the samples. With respect to staling, the gluten content and its ratio to starch are highly effective. During the bread shelf life, as its kinetic energy decreases, the cross-linking increases and intensities. In other words, the bread becomes harder and staler. However, using α-amylase and sourdough, the bread hardness and staleness are decreased as the starch swelling is limited and cross-linking between protein and gluten is inhibited. These two additives improved most sensory properties including resistance to breakage and rupture, porosity, kernel color, crumb color, proportionality of shape, back-side uniformity, flavor, taste, texture, chewiness, and larger size of the bread samples. This reason for these improvements can be due to starch hydrolysis by α-amylase and production of dextrins and CO2. According to the results, the bread sample containing 0.03% α-amylase and 6% lactic sourdough was selected as the best sample.
Ryhaneh Moghaddasi; Sara Movahhed; Hossein Ahmadi Chenarbon
Abstract
Introduction: The rheological properties of a bread dough describe its behavior under different process conditions. They are also central to its formulation, optimization, quality control, and better process capacity. A number of additives can improve the rheological properties of dough and breads. Fiber-based ...
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Introduction: The rheological properties of a bread dough describe its behavior under different process conditions. They are also central to its formulation, optimization, quality control, and better process capacity. A number of additives can improve the rheological properties of dough and breads. Fiber-based compounds and prebiotics in addition to gluten and starch, which have a large tendency to absorb the flour water, can affect the moisture distribution across the dough structure. Inulin and resistant starch are two types of prebiotics. Inulin is a water-soluble dietary fiber that is not absorbed by the enzymes at the upper section of he the digestive system and is partially fermented and metabolized by the microbial flora of the colon. Digestion-resistant starch is another prebiotic that acts as a food fiber and adds to the nutritional value. It can also improve the structure of the final product. In recent years, the rise in consumer awareness about health benefits of prebiotics has increased interests in functional foods particularly in bakery products. The present study qualitatively analyzed the effect of the prebiotics (i.e. inulin and resistant starch) on rheological properties of baguette bread doughs.
Materials and Methods: The study treatments are: Baking dough w/o inulin and resistant starch (Control); baking dough w 2.5% inulin (based on flour weight); baking dough w 5% inulin (based on flour weight); baking dough w 2.5% resistant starch (based on flour weight); baking dough w 5% inulin (based on flour weight); baking dough w 2.5% inulin + 2.5% resistant starch (based on flour weight); baking dough w 2.5% inulin + 5% resistant starch (based on flour weight); baking dough w 5% inulin + 2.5% resistant starch (based on flour weight); baking dough w 5% inulin + 5% resistant starch (based on flour weight). The treatments were rheologically tested by farinograph and extensograph after preparation. Study data were then analyzed using the completely randomized design. Means of data were also compared by Duncan's multiple-range test (α = 5%) in SPSS 16.
Results and Discussion: According to the results, the different levels of prebiotics (inulin and resistant starch) significantly improved dough water absorption compared to the control samples. This can be due to the presence of hydroxyl groups in the structure of the prebiotics, which increased the number of hydrogen bonds and thus water absorption in all treatments compared to the control. Moreover, these additives led to significantly higher dough development time than the control. This can be due to the hydroxyl groups in the structure of inulin and resistant starch, which increased the number of hydrogen bonds and thus cross-bonding with water. These additives also significantly increased the dough stability time compared to the control.This is a result of hydrogen attachments and hydroxyl bonding between gluten proteins (made up of glutenin and gliadin) and the prebiotics (inulin and resistant starch) that in turn improved the stability and strength of the doughs. As the dough stability increased, the dough softening degree after 10 and 12 minutes was also reduced, which was due to the hydrogen bonds resulting from hydroxyl cross-links of gluten with inulin and resistant starch. Note that the quality index increased when the stability and strength were improved compared to the control dough. According to the results, by adding different levels of inulin and resistant starch, the dough energy rised higher than the control sample after 45, 90 and 135 minutes. This is again due to (OH) hydroxyl bonds with hydrogen attachments between glutens and the prebiotics. In this regard, the highest resistance to extension after 45, 90 and 135 min was recorded for the treatments containing inulin and resistant starch whereas its lowest value was recorded for the control. This is due to the stable continuous lattice made by amylose in resistant starch granules, which led to the higher strength of other treatments than the control. Additionally, the increased dough resistance to extension can be due to the interaction of inulin and resistant starch with flour proteins. Regarding extensibility, significant differences were observed between the treatments and the control within all three time intervals. Accordingly, after 45, 90 and 135 min, the control treatment had the highest extensibility whereas the treatment with 5% inulin + 5% resistant starch (based on flour weight) had the lowest level of this parameter within these times. The increases in strength and stability of the doughs were caused by strong links between glutens and these prebiotics, which reduced the dough extensibility. The results showed that the highest dough ratio number after 45, 90 and 135 min belonged to the treatment with 5% inulin + 5% resistant starch (based on flour weight). The lowest ratio number was recorded for the control in these time periods. The gluten was the main factor behind dough stability. The large amount of hydroxyl groups in the structure of inulin and resistant starch led to formation of a better structured three-dimensional gluten lattice. In general, by taking all parameters into account, the treatment with 5% inulin + 5% resistant starch was selected as the best treatment.
Zahra Najafi; Sara Movahhed; Hossein Ahmadi Chenarbon
Abstract
Introduction: Cake is one of the most important and widely used cereals and a product of wheat flour. Usually, high-calorie in a variety of cakes is attributed to oils, eggs and sugar in their formulation. Nowadays, the risk of cardiovascular diseases is increasing in most parts of the world and the ...
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Introduction: Cake is one of the most important and widely used cereals and a product of wheat flour. Usually, high-calorie in a variety of cakes is attributed to oils, eggs and sugar in their formulation. Nowadays, the risk of cardiovascular diseases is increasing in most parts of the world and the demand for using the low fat and low cholesterol foods is increasing due to the relationship between excess fat and various diseases. Therefore, it seems that the partial or complete removal of oil and egg and replacing them with other substances in the formulation of the cake is very important. In recent years, the use of dietary fiber of different sources in food products is increasing due its beneficial effects on human health. Among agricultural products, the residues from the processing of oranges are rich in fiber that can be used as a dietary fiber in the food industry. Fiber is a general term for many different types of carbohydrates that is obtained from plant cell walls and is not decomposed by digestive enzymes in the human body. Formulating the food with citrus fiber could be very beneficial since the exisence of a variety of fiber compounds in the peel of citrus with neutral pH that the property may leads it to be widely used in a variety of foods. Others advantage is that it lead to improve the cooking performance, increase the water binding capacity, the oil absorption and improve the final texture of product with lower costs.
Materials and methods: In this study, the use of citrus fiber was studied in order to improve the structure and nutritional properties of muffin with a new formulation. In this regard, the orange fiber at three levels (0.5%, 1% and 2%) and with 25% of decrease in oil and egg was used in the muffin production process. In this study, the raw materials, including null flour, sugar, liquid oil, eggs, milk, salt, vanilla, baking powder and orange fiber were prepared from France ID Food Company. Two-step mixing method was used to prepare the dough. The cakes were placed at 180 ° C for 30 minutes. In all tests, the control treatment with code T, treatment containing 0.5% of orange fiber with code T1, treatment containing 1% of orange fiber with code T2 and treatment containing 2% of orange fiber with code T3 were determined. First, the chemical tests including moisture, ash, fiber and pH were conducted on the wheat flour. Then, viscosity determination was carried out usinga Brookfield viscometer, Also the density measurement performed on the muffin cake dough. Afterwards, the production of different treatments, the chemical tests including moisture, ash, fiber and pH as well as the staling tests were performed by two sensory and instrumental methods by Instron device and also the organoleptic characteristics (volume, crack, balance of shape, taste and aroma, chewiness, apparent texture, uniformity of pores in the cake center and the color of cake center and the outer shell) were conducted by using five senses on the produced Muffin Cake according to the standard method.
Results and discussion: For statistical analysis of data from physicochemical and sensory tests, completely randomized design and data from staling test from factorial experiment in a completely randomized block design was used and the mean comparisons were conducted by Duncan's multiple range test at probability level of 1% (α=1%) and by using SPSS software, version 16. Considering the results of viscosity and density of the muffin cake dough, the highest amount of viscosity and density belonged to the treatment containing 2% of orange fiber (T3) and control (without orange fiber). The highest percentages of moisture, ash and fiber were calculated for the treatment T3 and the lowest amounts were calculated for control. Also, the highest and the lowest amounts of pH were observed in the treatments of control and T3, respectively. Also, considering the results of staling test by both sensory and instrumental methods and in the intervals of 24, 48 and 72 hours after baking and in all time periods of treatment T3 had the highest score of freshness (delay in staling) and the treatment containing 1% of orange fiber (T2), containing 0.5% of orange fiber (T1) and control (T) had the lowest score of freshness, respectively. The control sample had the highest amount of staling in all days and the amount of staling increased in all treatments over time. It is noteworthy that at all time intervals, the control sample had the highest rate of staling and the staling rate increased for all treatments over time. Considering the results of sensory test, T1 was introduced as the best treatment and in most of the organoleptic characteristics such as taste, flavor, uniformity of pores, chewiness, and overall acceptance had no significant difference with the control sample and was the nearest sample to the control and had the highest score and the highest level of consumer acceptance.
Conclusion: The results showed that adding different levels of orange fiber has a significant effects on physicochemical and organoleptic properties of the muffin cake and replacing 25% of oil and egg used in muffin cake with 0.5% of orange fiber is possible and has enough acceptances.
Sara Movahhed; Elham Kakaei; Hossein Ahmadi Chenarbon
Abstract
Introduction: The most important treatment for celiac disease is a gluten-free diet throughout the lifetime of the patient. Corn flour is one of the alternatives for wheat flour in baking of bread and bakery products that are of high nutritional value and because of lack of gluten are suitable for people ...
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Introduction: The most important treatment for celiac disease is a gluten-free diet throughout the lifetime of the patient. Corn flour is one of the alternatives for wheat flour in baking of bread and bakery products that are of high nutritional value and because of lack of gluten are suitable for people with celiac disease. Moreover, potato flour is one of the best wheat flour alternatives in bread-making and is consistent with that; and now, not only in production of bread but also in production of other bakery products. Hydrocolloids are a branch of additives which are widely used in food industry. One of the most widely used gum in food industry and bakery is hydroxy propyl methyl cellulose gum, which is a derivative of cellulose. Considering the above mentioned facts; the aim of this study was to prepate baguette bread with a mixture of equal parts of corn and potato flour with hydroxy propyl methyl cellulose gum. In this regard, the effect of different levels of gum on qualitative properties of produced baguette bread was investigated.
Materials and methods: Treatments included an equal mix of corn flour and potato flour with 0.25, 0.5, 0.75, 1% hydroxy propyl methyl cellulose gum were prepared. Different chemical tests such as moisture content determination, ash, proteins, fiber and pH measurement were performed on samples of corn and potato flour and after baking on baguettes bread. Yield of dough and bread was calculated in order to determine the strength of dough, porosity and hollow of bread. To evaluate the organoleptic characteristics of baguette bread samples, the analysis of properties of bread with the five senses were using. Staling test based on sense and instrument method at intervals 24, 48, 72 hours after baking was performed on all samples of gluten-free baguettes. Simon Henry method was used for determining the volume of the sample bread. In order to analyze the results of test, a completely randomized design with three replications was used and the means by Duncan's multiple range test, in probability level a=1% by SPSS software in 16 versions compared.
Results and discussion: According to results, addition of hydroxy propyl methyl cellulose gum causes yield of dough to increase significantly comparing to the control sample. Generally, gums are hydrophilic compoundsand usually they are interacting with water to reduce the spreadability and stability of the presence of water in the system. Also, adding HPMC gum, decreases yield percent of baguette gluten free bread comparing to contrl samples. Reason of diminishing returns of bread samples containing gum is structural nature of HPMC gum that is capable of properly maintaining carbon dioxide. But there was no significant difference in ash and protein that it was for structure of used gum. By adding HPMC gum, water content of samples in compared to C treatment increased due to the high water holding capacity of used gum. Also adding HPMC gum will increase the amount of fiber in samples containing gum compared to instance treatment. Moreover, HPMC gum increases the volume and improve the color appearance of baguette bread samples containing gum in compare to instance treatment (C) but there was no significant difference in uniformity characteristics of back of gluten-free baguettes samples. Its reason is because of gum hydrophilic property which by increasing the viscosity can keep gas in dough and bread. Color improvement of baguette bread samples containing gum is increasing browning reaction because of adding gum. According to the results, HPMC gum at level of 0.75 and 1% of weight had positive impact on internal characteristics of baguette. Increasing porosity of baguette bread containing gum and improving their hole and seeds shape is for gum ability to maintenance of carbon dioxide and increase bread volume, also this gum prevent dry and hardening of bread texture due to water absorption. Aroma of bread is depend on maylard and caramelization reaction, so scent in bread with suitable browning reactions, increased and as gums are effective in increasing browning reactions of maylard so has desired effect on bread aroma. Also more used gum, will reduce water consumption, improve freshness and softening of bread tissue due to the interaction of hydrocolloids with water and reducing water retention during cooking and was thus a positive effect on the texture of bread. According to results, adding HPMC gum in level of 0.75 and 1% causes the staling time to reduce in three 24, 48 and 72 hours after cooking baguette bread containing gum (by sensory and device) compare to the treatment C. Furthermore, adding HPMC gum increases the volume of baguette bread samples containing gum compare to the instance treatment (C). Volume increasing is because of hydrophilic properties of gum that improve dough spread and maintenance of CO2 gas.
Conclusion: According to the results, treatments containing 1% HPMC gum had the highest water content and fiber. The amount of ash and protein in the samples containing hydroxy propyl methyl cellulose to the instance samples had a slight increase, but this difference was not significant. On the other hand treatment containing 1% gum had the highest dough yields and the control sample had the lowest. Also, yields decreased with increasing gum than the control bread. Other treatments containing 1% gum had the highest privilege organoleptic than other treatments. Also according to the staling test results in sensory and device method, at intervals 24, 48 and 72 hours after baking, treatment with 1% gum has the lowest time of staling. Also treatment containing 1% gum had the most volume and the control the lowest one.
Fatemeh Roshani; Sara Movahhed; Hossein Ahmadi Chenarbon
Abstract
Introduction: Potato is raw food stuff with high popularity worldwide when deep fried. Deep frying is a fast budget process used for preparing savory food. In this process, oil is used both as a heating intermediate and as an ingredient producing calorific products. Nutrition has become a major health ...
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Introduction: Potato is raw food stuff with high popularity worldwide when deep fried. Deep frying is a fast budget process used for preparing savory food. In this process, oil is used both as a heating intermediate and as an ingredient producing calorific products. Nutrition has become a major health concern, particularly in developmental countries where obesity has turned into an ever-increasing problem, mostly among children. Deep frying is a widely-practiced method for cooking fast foods with desirable sensory properties. Frying is a process of simultaneous heat and mass transfer where heat is transferred by a combination of convection and conduction. At high temperatures, a great amount of moisture content is also lost as vapor, compensated by oil uptake in foods. Oil uptake of foods is an important concern associated with their moisture loss. Thus, it is important to examine moisture loss during frying. Today, the interest in production and consumption of low-fat French fries is on the rise. At the same time, the frying method has a great effect on quantitative and qualitative characteristics of foods. The final moisture content in French fries is about 38% of the product’s final weight. sufficient moisture content is therefore required in French fries to achieve both a soft moist core and a crunchy tasty crust. Numerous methods or pretreatments such as ultrasound and drying may improve these properties. Moreover, finding relationships between different variables during deep frying by modelling may provide an optimal control over process conditions thereby improving the quality of the final fried product. In the present study, effects of ultrasound and drying pretreatments on moisture content, oil uptake, activation energy and effective moisture diffusion coefficient in Satina potato slices during deep frying were investigated. Material and methods: 10kg of Satina potatoes were provided and stored at room temperature. Bahar vegetable frying oil containing cotton seed, sunflower and soybean oils was used for frying. For each experiment, potatoes were washed, peeled and sliced by a household French fry cutter with 1.2×1.2×4 cm dimensions. The cut samples were placed in a plate to avoid moisture loss and were washed with distilled water to remove surface starch before frying. The excess surface water was also removed by a hygroscopic paper. Then ultrasonic pretreatments at two frequencies of 20 and 40 kHz were applied for 15min, and the drying pretreatment was also conducted at 60°C for 15min. To fry the samples the fryer was filled with 1.5 lit of oil. The deep fryer was set to adjust temperature and frying time automatically. When the temperature reached the set value, 100-120g potato samples were placed in the frying basket, which was then submerged in oil automatically. The pretreated samples were fried at 170°C and 190°C for 5, 7 and 10 min. Oil uptake and moisture loss during frying were recorded at certain time intervals. Next, the fried samples were removed from the deep fryer and were placed on a mesh tray to remove the excess oil. The oil uptake and moisture content were analyzed. Oil content was measured by the Soxhlet method. It is based on extracting fat from foods using proper solvents. Moisture content was measured by drying in a convection oven at 105°C until reaching a constant weight. Moisture content and oil uptake of potatoes slices during deep frying were also modeled versus time. The factorial experiment was laid out in a completely randomized design with three replications, and means were compared using Duncan’s multiple-range test. SPSS 14 was used for statistical analyses. Results & Discussion: According to the results, samples pretreated with 20 kHz ultrasound at the same temperature and time conditions had higher moisture content than those treated with the 40 kHz frequency. The highest moisture content was found in samples pretreated with 20 kHz at 170°C for 5min. On the other hand, samples receiving 40 kHz ultrasound pretreatment showed higher effective moisture diffusion coefficient and activation energy than those receiving the 20 kHz pretreatment. The highest diffusion coefficient was achieved using 40 kHz at 190°C for 5min, whereas the highest activation energy was observed with 40 kHz at 170°C for 10 min. It should be mentioned that the effective diffusion coefficient was within the 6.95 × 10-8 – 8.80×10-8 m2/s (R2=0.99) range. Activation energy was also in the range of 13.161 – 16.307 kJ/mol (R2=0.99). Conclution: Samples pretreated with 40 kHz ultrasound showed the lowest oil uptake as compared with those pretreated with 20 kHz frequency. The highest oil uptake was observed for samples pretreated with 20 kHz at 170°C for 10 min. Through the multivariable regression analysis, it was found that the exponential model had the best fitting in predicting changes in moisture content and oil absorption.
Sara Movahhed; Sanaz Zharfi; Hossein Ahmadi Chenarbon
Abstract
In recent years different additives have been used for enhancing quality and nutritional value of bread. Banana flour is a useful additive that contains significant amounts of fiber, protein, minerals and vitamins. In this research chemical tests (moisture, ash, protein and fiber) were carried on the ...
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In recent years different additives have been used for enhancing quality and nutritional value of bread. Banana flour is a useful additive that contains significant amounts of fiber, protein, minerals and vitamins. In this research chemical tests (moisture, ash, protein and fiber) were carried on the wheat flour, Banana flour was then added at levels of 10, 15 and 20% and toast breads were prepared according to semi-industrial method. Some rheological properties of dough samples containing banana flour were determined and then organoleptical properties of Toast breads as well as control treatment were measured by sensory panelist. Based on the results, incorporation of banana flour at various levels (10, 15 and 20%) improved all organoleptical properties of banana breads compared with control samples. Also increased the absorption of water, extension time, resistance, volumetric value and decreased the extremely ability of the samples. Also that all the samples of banana powder improved the resistance of the batch to tension and energy tests. In addition, samples containing 15 and 20% banana flour were found to be the best samples.