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Showing 28 results for Staling


Volume 3, Issue 10 (10-2006)
Abstract

One of the most effective surfactants, which is increasingly used to retard the staling of bread, is Sodium stearoyl lactylate (SSL). This research was carried out to assess the staling of flat bread containing different levels of SSL with different methods. Therefore, Taftoon bread was baked from dough containing 0.25, 0.50, and 0.75% SSL with standard method, sensory and staling evaluations were done on days 1, 2 and 3 by means of 5 trained panels of referees. Moisture content of the breads was determined in the same days with standard method. The texture of breads was evaluated by tensile, compression and shear tests on days 1, 2, 3 and 4 with Instron. Trained panel of referees could not find any significant difference between the sensory characteristics of breads but showed that chewing ability of the bread containing 0.50% SSL was improved from 5.5 to 6.1. Results of texture measurement showed that the force required to compress, shear, and tensile breads was reduced in breads containing SSL With regard to the results of the other tests; we could reveal that compression test was not suitable for Taftoon bread, which is flat bread and has a low thickness. Moisture of the breads did not change significantly on the tested days. The scores of staling were reduced, although most of them were not significant and this decrease was from 3.4 to 1.8 for the standard and from 3.6 to 2 for the bread containing 0.25% SSL and from 2.4 to 2.6 for the bread containing 0.50% SSL and from 3.7 to 2.4 for the bread containing 0.75 %SSL. Therefore we could conclude that by using sensory evaluation and texture analysis together, we could assess the bread staling.

Volume 4, Issue 14 (10-2007)
Abstract

According to the statistics ,consumption of the bread has the highest value in Iran. Regarding the high wastage of different breads, which is mainly due to low quality, low shelf life and staling, we will answer one of the most important nutritional problems of our country , if reduce or at least retard its rate by means of research. This research was carried out to determine the effect of different levels of sodium stearoyl lactylate (SSL) on dough rheological properties and quality of Taftoon. So SSL was mixed with flour at levels of 0.25%,.0.50% and0.75%and the rheological properties of the resulting doughs were determined by Farinograph and Extensograph and optimum level of SSL addition was determined ,regarding the results. Different treatments of breads were baked and sensory analysis was done in days1,2 and 3 by means of trained panel of referees. The texture of breads were evaluated by krummer, compression and rubber tests in days 1,2,3 and4 with Instron. Moisture content of the breads was determined in days1,2 and3.Results of Farinograph and Extensograph , showed that SSL improved dough properties .The results indicated that bread containing 0.75%SSL had the best quality and was the one to mostly retard the staling rate and improve the texture of bread, but there was no significant difference between breads containing 0.50 % and 0.75%SSL .

Volume 4, Issue 15 (12-2007)
Abstract

The effect of retrograded waxy corn starch on the rheologlcal properties of wheat flour dough and the final quality of baguette breads was investigated. Waxy corn starch pastes (10%) were stored at 5 °C for 7 days and the powder specimens of retrograded starches thus obtained were substituted of wheat flour for bread making at levels of 3, 5 and 7%.The rheological properties of dough were evaluated by farinograph and extensograph. Specific volume, moisture content and firmness of breads, were measured over a period of 0, 2, 4, 6 days. Sensory characteristics of breads were evaluated in the period of 24, 48, 72 storage hours. Water absorption was increased by retrograded waxy corn starch. Generally, the substituted flours developed viscosity rapidly but could not maintain the stability of paste viscosity. The dough made from the substituted flours exhibit weaker and less stability than that made from the wheat flour. The bread which contained retrograded waxy corn starch showed an increase in specific volume and the result of sensory evaluation showed that they were very acceptable. During the storage of bread, increase in firmness was suppressed by adding retrograded waxy corn starch. Results showed that incorporation of 5 % or 7% retrograded waxy corn starch produced considerable improvement in the shelf life of bread. During of storage (6 days), the bread including retrograded waxy corn starch maintained moistness and softness. As a result retrograded waxy corn starch could be used for bread making to improve the quality of bread.

Volume 6, Issue 20 (4-2009)
Abstract

    Bread can be referred to as an unstable material, and bread staling as a multifaceted process involving physical, chemical, and sensory changes that are related together. Bread staling has been the subject of a number of studies to obtain an understanding of its intrinsic mechanism and thereby to modify dough recipes and increase shelf life. Because of the complexity of the process, most researches address specific bread properties during its shelf life. An overall description of the staling process remains to be evaluated. Bread staling is characterized by many physical and chemical phenomena such as changes in texture, water migration, starch crystallization, and component interactions. Analyses of bread staling have evolved over time, as instrumental technology and knowledge of the subject have progressed. Various analytical techniques are available for monitoring changes at macroscopic, microscopic, and molecular levels. Careful selection of techniques offers a strategy to investigate the bread staling mechanism.  Frequently experimental approaches attributes of stale bread have involved x-ray diffraction, differential scanning calorimetry (DSC), rheological, chemical, sensory and molcular investigations. The combination of various techniques can be a powerful approach to the study of physiochemical changes of complex phenomena. Choosing an appropriate method becomes a significant factor in interpretation of results in time-dependent processes. Scientists need to approach this complex problem with well-planned strategies so experimental data can serve as a fundamental understanding of molecular structure and function relationships in bread.

Volume 6, Issue 22 (10-2009)
Abstract

A structural study of traditional Iranian breads, in relation with staling has been carried out in this research by Scanning Electron Microscopy (SEM) employment. Popular Iranian flat breads of Barbari, Lavash an sangak were selected and stored up for durations  of  24, 48 and 72 hours. During these time intervals, staling  phenomenon occurred but the rate was varied among different bread kinds. It is evident that staling progress with time lapse, but it is different for 24, 48 and 72 hours of storage times. Microscopic study showed a quicker process of staling in Barbari bread during the first 24 hours of storage. Sensory evaluation was done for all the samples in respective time intervals. Results indicated no significant differences among panel judgements while there existed significant structural differences among bread samples. All samples became staled as compared with control, but Barbari bread became more stale as compared with  Lavash and Sangak. Overall results reveal that retrogradation of starch granules occurs during storage of bread, particularly at time lapses of 48 and 72 hours. Staling phenomenon occurred in all breads while its rates was different. In addition, it was shown that coagulation of gluten network during baking and its intensity during storage was an important factor. Flour components, baking conditions, time and baking process were also important interventing factors.

Volume 6, Issue 22 (10-2009)
Abstract

  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.  

Volume 7, Issue 26 (10-2010)
Abstract

(Received:87/4/26   Accepted:88/7/24)   In this study, lactic fermentation was used in order to improve the quality of loaf bread (baggett). Lactobacillus plantarium was cultivated in a medium composed of wheat flour and water and added in bread dough formulation at 0, 5, 10 and 15% concentrations. After baking, Staling, physicochemical (pH and acidity) and organoleptic properties (crust characteristics, taste and odor) were evaluated. Results showed that bread acidity as the concentration of sourdough increased in dough formulation. Acidity and pH of sample bread that contained 15% sourdough was 6.5 and 4.87 respectively. Also, in this sample staling and quality changes during storage were at least. Highest score of taste were belonged to sample contained 5% sourdough. Sample contained 15% sourdough gained highest score of odor and crust properties.

Volume 8, Issue 4 (10-2006)
Abstract

The effect of flour extraction rate on flour composition, dough rheological characteris-tics and the quality of Iranian flat breads (lavash, taftoon and barbari) and their staling rate was investigated. Flours with different extraction rates (70, 75, 80, 83, 86, 88, 90 and 93) were subjected to different tests. Resultes indicated that, by increasing the extraction rate, the amount of protein, fat, fiber, ash, wet gluten, water absorption and the color of the flours all increased but the moisture content, sedimentation value and falling number decreased. Rheological studies of doughs by farinograph showed a reduction in dough stability, whereas the dough mixing tolerance index increased along with the extraction rate. By using an extensigraph it was shown that dough resistance, extensibility and the area under extensigram curves were decreased by increasing the extraction rate. A study of the effects of flours with different extraction rates on bread quality, showed that the overall quality of breads is generally affected by the flour extraction rate. Sensory analy-sis of breads in respect to overall quality and staling indicated that the desirable rates of extraction for lavash, taftoon and barbari, breads are 88, 90 and 88 respectively.

Volume 8, Issue 28 (4-2011)
Abstract

Dietary fiber has become a matter of considerable public interest in recent years because of its known beneficial physiological and metabolic effects. Since, fiber intake is commonly lower than recommended amount (30g daily),the fortification of bread with fiber can play an important role in achieving health benefits. The aim of this study was to add oat bran at 5, 7.5 and 10 % levels to the Sangak flour and study the rheological characteristics and quality and shelf life stability of the bread. The rheological characteristics of dough were studied on the farinograph and extensograph. Then, Sangak bread baked under standard condition and kept for 24, 48 and 72 hours at room temperature and  samples evaluated  by 10 trained panelists. Texture of bread samples analyzed for extensibility, sliceability and  compression by Instron (Universal Testing Mashine) at 24, 48 and 72 hours at room temperature. Also, moisture of bread samples determined by standard method  and compared with control. Results indicated that use of oat bran increased  water absorption and  weakened dough. Also, the extensograph results  showed by the addition of the bran to the flour, resistance to extension increased and dough could kept the gases during fermentation. The results of the sensory test of Sangak bread  showed that by the addition of oat bran to the sangak dough , the quality of the bread was low and lower quality was in the case of high percent of the bran (10%). The texture properties of the breads at 24, 48 and 72 hours, showed they were delay in staling phenomenon and the late thoughness happened. Acid detergent fiber and neutral detergent fiber values increased with increasing levels of oat bran.  

Volume 8, Issue 32 (10-2011)
Abstract

  Enzymes of wheat flour have an important role on the quality of various backing products, especially bread. The knowledge of their activites can assist us to produce the high quality products. On the other hand, the most wheat flours in the countery have low α-amylase activity. Therefore, optimization of flour α-amylase activity is important for production of high quality bread. In the present work, chemical properties of three wheat flours varieties (Mahdavi, Kavir and M7318 that are produced in Isfahan province) were investigated. To show the changes of α-amylase activities, the activities of enzyme were measured during the germ growth times up to 72 hours. α-amylase activity of flours was also optimized according to falling number 250. The effect of this optimization on the bread texture in four different times after baking were then evaluated. The results showed that all three varieties had lower levels of α-amylase activity than the optimum level. The results indicated an increase in the activity of α-amylase during the growth of germ up to 72 hours. The results of the determination of the best blending percentage of germinated wheat flour with baking flour indicated that optimization of α-amylase activity is essential in terms of both wheat varieties of flour and germination times of wheat germ. Bread texture analysis indicated that bread produced with optimized α-amylase activity flours using appropriate percentage of germinated wheat flour have softer texture and lower staling. Wheat variety had also an important effect on staling so that bread produced with Kavir variety flour had softer texture than other varieties. Breads produced with optimized flour using 72-hours germinated wheat flour had softer texture than the breads made by optimized flours with other germination times.

Volume 8, Issue 33 (11-2011)
Abstract

In this research the effect of bioemulsifier(emulsan) on the staling process and the quality of  Barbari bread  was investigated. The bioemulsifier from the Acinetobacter calcoaceticus was produced at 1/8 gr in each littre of calture.After the extraction and purification ,0/05,0/2,0/5,0/75 and 1% were added to Barbari bread formulation and were compared with the control bread.The hardness of  bread were measured after 1st, 2nd and 3rd days of  baking. The sensorial tests were conducted on breads after baking.In this study,the pleasant effect for delaying the staling process by using 0/5% of emulsan was achieved. The results of  Instron test showed that the 0/5% of emulsan increased the stability of bread significantly,in a way that the average of the necessary power for cutting the samples reduced from 243/9 in the control sample to 225,206/5,186,180/6 and 154/5 in the samples with  0/05,0/2,0/75,1 and 0/5% bioemulsifier. During 3-days  storage  time of bread containing bioemulsifier on the 2nd and 3rd days after baking. As a result,bioemulsifier is effective in reduction of the staling on the2 nd and 3rd days after baking. The results of sensorial measurement over lapped with the achieved results of Instron.In addition to the results of the sensorial measurements,there has been a positive change.

Volume 8, Issue 34 (12-2011)
Abstract

At present one of the bread problems in our country, is its quality that has an important role in wastage. Among traditional breads, sangak has a better nutritional value and organoleptic properties, but unfortunately it's shelf-life is short and stales quickly. Addition of rye flour to wheat flour IS one of the methods which is used in retarding bread staling. Since rye flour has a high amount of pentosan , its addition to wheat flour improves bread shelf-life. In this research the effect of  adding rye flour to wheat flour on sangak bread shelf life also its influence on sensory characteristics of produced breads was investigated. At first rye and wheat four properties including moisture, ash, protein content, falling and zeleni number, and physical properties i.e particle size was determined. Then mixture samples were prepared by adding different ratios of 5, 10, 25 percent of rye flour to wheat flour. Physical, chemical and rheological properties of the samples and mixtures were determined. Doughs were prepared and composite breads were baked. Finally, rye breads were examined organoleptically by a trained sensory evaluation panel, one, 24 and 48 hours after baking for acceptance and staling rate. The results indicated that:addition of rye flour to wheat flour did not have significant influence on dough rheological properties such as farinographic and extensographic properties, however sensory characteristics of samples were affected i.e increasing rye flour resulted in form, shape and porousness improvement of samples but it had a negative effect on upper and bottom surface properties, coincidence no change was observed about samples chewing ability and hardness.

Volume 9, Issue 36 (10-2012)
Abstract

  Barbari is one of the most common flat bread in Iran, with a relatively short shelf life. In this study different packaging material and gas composition inside the packaging were investigated in order to extension the shelf life of Barbari bread enriched with whole soy flour. Gas compositions of packages were selected as 70%CO2 and 30%N2, 50% CO2 and 50%N2 and normal air considered as control. Bread samples were packed into the different packaging i.e. oriented polypropylene (OPP) (33 μ) as the control, high-barrier laminated of Polyethylene terephthalate – Aluminum – Linear low-density polyethylene (PET–Al–LLDPE) (12-7-65), and vacuum bags PET-PET-LLDPE (12-12-65). Quality characteristics of bread samples were evaluated during 21 days of preservation in ambient condition (25 ± 1°C and 38 ± 2% relative humidity). Microbial stability of bread, texture as staling rate index and organoleptic quality of the new products estimated periodically. In the treated and control samples increasing Co2 concentration caused increase in the both hardness and shelf life. Organoleptic test showed that, CO2 gas affected the bread taste with undesirable taste under MAP (modified atmosphere packaging) storage. 3 layers Packages contains aluminum due to high resistance to vapour demonstrated more effect on maintaining quality and softness of bread during time. Vacuum package and 3 layers Packages also prevents microbial bread spoilage by prevention of oxygen entering in packages.

Volume 10, Issue 38 (1-2013)
Abstract

In this research, different amounts of gum tragacanth (0.5%, 1%, 1.5% and 2% w/w) was added to wheat flour and its effects on bread quality parameters including moisture, specific volume, crumb firmness, color, water activity and bread staling during storage was evaluated. The results suggested that addition of gum tragacanth increased moisture but decreased crumb firmness, loaf volume and specific volume in all samples with reference to the control sample. Measurement of crust and crumb color showed that addition of gum tragacanth at all concentrations significantly decreased lightness of crust and crumb but increased red- and yellowness of both crust and crumb (p  

Volume 11, Issue 45 (3-2014)
Abstract

In this research modified corn starch(pregelatinisation) was used at levels of 3,5,7,10% levels to substitute wheat flour and production of barbary bread .Chemical analysis (moisture,ahe,insoluble ash, protien, fat, fibre, pH, particle size, moisture and dry gluten zeleny test, falling number was determined on corn modified starch ,blank and treated flour. The  rheological  properties of dough were also evaluated by farino,extenso amylographs. Staling analysis was done in days of 1,3and 5 by 6 trained panel. Moisture, ash, acid insoluble ash, moisture and dry gluten, protein,fat, zeleny number, pH was descreased by corn modified starch(pregelatinisation). falling number increased by corn modified starch(pregelatinisation).But  fibre content was not changed. The results of  rheological tests showed,That water absorption and softening degree was increased but stability,development time and  quality number was reduced in farinogram and resistence to extention, extensibility and  area under curves was improved in extensogram.The results of amylograph test showed that gelatinization tempretur was reduced,and peak viscosity of blank speciment was not significantly different with pregelatinization starch speciment(5%).The results of sensory test showed that treated breads quality were acceptable and were retareded staling.  

Volume 12, Issue 47 (7-2015)
Abstract

    Simple and corresponding impacts of adding acidic improvers (Lactic Acid , Acetic Acid and Citric Acid ) on bread staling has been researched twice in 3 levels( 0%, 0.25 % and 0.5 %) by factorial experimental method .There was an orthogonal comparison between the two treatments (acidified treatments and sourdough groups) in the second stage. The effect of lactic acid on bread staling was significant 24 hours after baking the bread .Different levels of lactic acid and citric acid had significant effect on bread staling 48 hours after bread baking. Finally -24 and 48 hours after bread baking- orthogonal comparison among our 6 selected treatments showed that there was a significant differences between two groups.The sourdough treatments had the least scores .Among the final treatments ,containing  0/25% acetic acid had the most scores, the treatments containing  0/25% lactic acid and the control sample had gradually a better score(from 24 to 48 hours).According  to these results, the sourdough can be processed , in a way that the bread has enough amount of acetic and lactic acid.    

Volume 12, Issue 47 (7-2015)
Abstract

Nowadays, additives are commonly used in cooking industry. Emulsifiers are one of the important materials generally used to improve the quality and efficiency of dough, to make the usability of dough easier, and to reduce dough wastage through delaying the staling time. The purpose of this study is to investigate the influence of adding two kinds of emulsifier including DATEM and Glycerol mono stearate  In 3 levels of %0,% 0/2, and %0/4 and Lipase Enzyme in 3 levels of 0, 100, and 200 PPM(activity 25KLU/g). The influence of adding above-mentioned materials was sought in qualitative and quantitative features of doughnut made from solid dough (texture, moisture, activity water  (AW), specific volume, porosity, and general acceptability). According to the random statistical study and the obtained significant difference (p<0/05) among treatments, it was shown that the combinations with %0/2 of Datem, %0/2 of GMS and 100 PPM of Lipase Enzyme presented the most specific  volume, porosity, moisture and the least hardness level, and consequently low speed staling 2 hours after cooking and 4 days after maintenance. This instance won the highest grade from tasting judges. The result indicated that after the experiment the qualitative and quantitative features of doughnut improved in comparison with the instance case. The case with %0/2 of Datem, %0/2 of GMS and 100 PPM of Lipase Enzyme showed lower speed of staling. Other parameters such as moisture level, activity water (AW), volume, porosity level, and general acceptability also presented better condition in this case.  

Volume 12, Issue 47 (7-2015)
Abstract

Because of  importance of  bread, shelf life and quality control be noticeable for bread specialist, cause of  this research was assaying synergistic effect of apple pomace and sodium stearoyl -2-lactylate on rheological properties and the shelf life of oven based  Barbary  bread. three percent of dried apple pomace (%5,%8,%11) was ready on cabinet drier on 58°c, and SSL was added up to %1,%5 (w/w of flour) . rheological properties of dough was studied with  two experimental method (farinograph , extensograph) and  texture of the bread sample analyzed for shear by instron (Universal Testing Mashine) at ,0,24,48,72 hours at room temperature sensory evaluation of  bread for sample and control  wasstimated in 1,2,3 days with 5 panelist. respect to rheological properties,sample with %8 apple pomace and %0/5 SSL was acceptable  to panelist .all sensory evaluations was upper  than control . and analytical resultsby instron indicated that this sample delay staling than control . results indicated by the use of  apple pomace in flat breads delayed the staling rate and addition of Appropriate emulsifier  has synergistic effect and itimproved the rheological properties  

Volume 12, Issue 49 (10-2015)
Abstract

  The effect of adding Eleaagnus angustifolia  powder to quality characteristics of burger’s bread                an 5,10 and 15 percent levels was checked. Moisture and tissue’s characteristics (Hardness,Springiness,cohesivness) of treatment and blank breads was measured in first, third and fifth days. A test was done  Hedonic test, color measurement and, assessment of porosity and scattering of cavities in bread’s texture in first day.The results show increasing levels of Eleaagnus angustifolia  in breads lead to increase moisture, decrease volume , porosity and darker appearance than to control sample.The evaluation of textural preperties determined above the 10 perecent levels of Eleaagnus angustifolia  powder lead to increase textural Hardness of bread.on the other hand, adding Eleaagnus angustifolia’s powder , in all levels , lead to reduction in of intransitive powder for cutting beard. In terms of staling process , during the retention time , the sample which contains 10 perecent of Eleaagnus angustifolia’s powder staled slower than the other sample in the period of maintenance and  15 percent’s sample had most stale’speed. According to analysing the sensory evaluation, 10 percent sample had most acceptance. Generally according to the results treatment bread included 10 percent of eleaagnus angustifolia’s powder,will suggest for greater acceptance ,lower hardness, procrastination in staling and increas the amount of fiber.  

Volume 13, Issue 51 (7-2016)
Abstract

Bread is the main source of a large part of the energy, protein, minerals and vitamins required by humans. Aloe Vera is one of the oldest medicinal plants that beside of fiber, minerals, vitamins, amino acids and natural sugars, have antimicrobial agents, anti-inflammatory and antioxidant Therefore, its use helpful for the prevention and treatment of Alzheimer's, heart disease, digestive problems. This study examined the effect of addition of aloe vera powder in quantities of 1, 3, 6 and 9% (w / w based on flour) on the quality of Barberi bread, as well as changes in microbial, texture, color and water absorption properties of bread within 72 hours in order to produce the functional bread. The results showed that the adding of aloe vera powder, causing controlling the activity of microorganisms and mold and yeast, increase swelling power and reduce staling the bread. However, volume, brightness, Points smell, taste and the ability to chewing has declined. In general, investigation of breads characteristics in this study showed that the adding powder of aloe vera until 1%, causing improve the quality of shelf life and increase the healthly value of Barbari breads that is produced.

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