Showing 27 results for Shahedi
N. Meghdadian, M. Shahedi, G. H. Kabir,
Volume 8, Issue 1 (spring 2004)
Abstract
Iranian flat breads generally have short shelf life. The result of this situation is usually enormous bread wastage. Among the most important factors involved are lack of proper packing and storage methods. In this study, the best temperature for bread packing was determined and the effects of three types of plastic wrapping on Taftoon bread baked of the typical flour were investigated after 72 hours of storage. These wrappings included a two-layer wrapping of oriented polypropylene and polyethylene (OPP/PE) with a thickness of 60 µ, a three-layer wrapping of PP/PE/PE with a thickness of 70 µ, and a two-layer polyethylene with a thickness of 70 µ together with cardboard and plastic. Bread packing was carried out at two different temperature ranges (20-25oC and 45-50oC). Results from moisture measurements and water activity test indicated that the characteristics of breads packed in different wrappings showed significant differences (p<0.01). Moisture percentage and water activity (aw) were lower in layers with higher permeability to moisture and water vapor and, consequently, algal growths reduced in these wrappings. Reduced moisture content, however, reduced the final bread quality score. It was also found that employing cardboard covered in polyethylene had no significant effect on bread shelf life during 72 hours of bread storage. Another finding from the present study was that packing a large number of 10×10 cm bread pieces within one single wrapping with cardboard and plastic was satisfactory and that the presence of the cardboard helped maintain bread shape during transportation and storage.
S. Bahrami, M. Shahedi,
Volume 8, Issue 1 (spring 2004)
Abstract
In this study, the effects of quality and quantity of protein in flours with 95% and 70% extraction rates obtained from Mahdavi and Tajan wheat cultivars each baked at two different durations (100 and 75 sec.) and temperatures (210 and 250°C), after wrapping in polyethylene packages with 40µm thickness were investigated. All tests were carried out during 168 hours after packing and at 24h intervals.
Results indicated that bread staling was affected by wheat cultivar, flour extraction rate, and storage time. Bread prepared from Tajan flour had lower firmness and staleness than that prepared from Mahdavi. High bran content bread was firmer than that with lower bran content. Organoleptic tests indicated that bread baked with 95% flour and bread baked at high temperatures with short durations were not very acceptable.
L. Rozbeh Nasiraei, Sh. Dokhani, M. Shahedi, R. Shokrani,
Volume 9, Issue 4 (winter 2006)
Abstract
The Two cultivars of kiwi fruit, Hayward and Abbot, with the desirable quality were harvested on time from Valiabad, a region in Tonekabon (Mazanddaran Provicnce). Fruits were graded and packed in the wooden boxes, cartons and low density polyethylene (LDPE) films, the fruits were cold stored in a proper and constant conditions (T= ±0.5 & RH=90-95%) for a period of 6 months. Samples were taken in completely randomised design from each package for intervals of 30±3 days and during storage (6 months). Chemical characteristics such as the total soluble solids(TSS), titratable acidity as citric acid, dry matter, vitamin C and the Physical characteristics such as yield point (Y.P.), yield point strength (Y.P.S.), penetration force (P.F.) and penetration stress (P.S.) were measured. Statistical analysis was performed with the factorial experiment in an unequal completely randomized design and the means compaired by Duncan multiple range test. The results indicated that, cv, Abbot has shorter shelf life, 4 months, compared to Hayward with 6 months storage period. Hayward contained more dry matter than Abbot throughout the storage period. Total soluble solids of cultivars increased and titrable acidity as citric acid decreased during storage. Vitamin C of Abbot was more than Hayward throughout the storage. Total factors in relation to texture and physical properties decreased by time such texture Hayward cv.after six month storage and in Abbot after four month storage was softer. As the final conclusion, wooden bins packaging for longer storage and plastic packaging for monotonous rippening of kiwifruit was the best in compared with other packaging.
M. Soleymani, M. Shahedi,
Volume 10, Issue 1 (spring 2006)
Abstract
The Drying process is one of the most important factors which are effective on the milling quality of rice and its economic value. In order to investigate the effect of dryer parameters on milling quality of rice and their relationships, one of the usual rice varieties (Binam) of Gilan province with an average milling quality and the initial moisture content of 20.5% was selected. Drying process was performed on the basis of a complete randomized design with 20 treatments and 3 factors including temprature (at five levels of 30, 40, 50, 60 and 70 °C) , air velocity (at two levels of 0.5 and 2 m/s) and final moisture content of paddy (at two levels of 10.5% and 14% on wet basis equal to 11.7% and 16.3% on dry basis respectively). Results of the experiments indicated that increase of temprature or air velocity reduces drying time but increases drying rate constant (K). It also revealed that decrease of final moisture content of paddy increases drying time significantly, but doesn’t have any significant effect on drying rate constant (K). Correlation test indicated that milling loss (breakage) has a negative relation to drying time and a positive relation to drying rate constant(K), however, bending strength has a positive relation to drying time and a negative relation to constant of K. Regression of qualitative properties of paddy including: milling loss (breakage) and the bending strength over drying time and constant of K revealed that drying time is a better criterion for predicting the mentioned qualitative properties.
M. Shahedi, Sh. Dokhani, Gh. Kabir, N. Zamindar,
Volume 10, Issue 1 (spring 2006)
Abstract
For production of fabricated potato chips, two potato- cultivars namely, Agria and Marfona, were obtained from Daran region of Isfahan Province and stored in cool storage at a proper and constant conditions ( T = 9°C and RH=85% ) . Specific gravity, dry matter and reducing sugars were determined at the time. Potato granule was prepared from both the cultivars by the Add-back procedure. To prepare a sheetable dough, potato granule, corn flour, emulsifier, shortening, water, starch, salt and wheat flour were used. After formulation of a non- adhesive dough, it was sheeted to thickness of mm and formed into slices of 3 cm diameter. These slices were processed by baking, vacuum drying, deep frying and combination of pre-drying and deep frying methods. To select the sample with the best texture a multiple comparison taste panel was held .The best method was baking at 125 for 30 minutes. To improve flavor and acceptability of selected chips, different seasonings (garlic powder, pepper, thyme, lactic acid, onion powder, salt, sugar) were used in chips formula and were compared by multiple comparison and triangle tests. Panelists selected treatments containing salt, pepper and garlic powder as the best formulatins.
M. Soleimani, M. Shahedi,
Volume 10, Issue 2 (summer 2006)
Abstract
Isotherm curves are useful for the designing of dryer as well as controling of the seed moisture content during storage and drying process. To study the curves, this research was performed on the basis of two factorial experiments including three factors: (1) hybrid at two levels (Three Way Cross 647 and Single Cross 704) (2) temperature at 6 levels (from 5 to 55°C) and (3) Relative Humidity (RH) at 5 levels (from 10 to 90 percent) for the analysis of the adsorption and desorption phenomena. For maintaining RH at the above mentioned ranges, glycerol solutions with different concentrations were used. The results showed that the relationship between solutions concentration and their RH was non-linear and somewhat related to temperature. Also, statistical analysis displayed that for 3 factors of tepmerature , RH and hybrid, the effects on Equilibrium Moisture Content (EMC) in both adsorption and desorption phenomena were significant at α=1%. Comparisons of means showed that hybrid 704 had higher EMC values than did hybrid 647 under the same conditions, in other words, hybrid 704 produced lower aw than did hybrid 647 at the same moisture content. Fitting experimental values on non-linear models (Henderson, Chung-Pfost and Oswin) showed Oswin as the best model for adsorption and desorption curves for hybrid 704 and also for adsorption curve for hybrid 647 , but the best model for desorption curve for hybrid 647 was Chung-Pfost.
M. Salehifar, M. Shahedi, Gh. Kabir,
Volume 10, Issue 2 (summer 2006)
Abstract
Bread is widely consumed as a staple food all over the world. The major ingredient of bread is wheat flour which suffers of a couple of shortcomings, such as essential amino acids. To overcome of this problem, a great deal of attention has been made by fortification of bread with different cereal and legume flours. In this study, wheat flour was replaced with 0, 10, 20, 30 and 40% of oat flour to investigate of its effects on dough texture and sensory attributes at room and lower temperatures for 0, 24, 48, 72 h in improved and unimproved breads. Improved formula containing levels of blanched oats, 1.5% fat and 60 ppm ascorbic acid. Addition of oat flour improved bread shelf life. Breads baked with up to 20% oat flour, were considered to be stable along over the time as indicated by sensory evaluation. Samples substituted with 30% and 40% oat flour had the high intensities of bitterness.
N. Zamindar, M. Shahedi,
Volume 10, Issue 3 (fall 2006)
Abstract
To prepare a sheetable dough, potato granule and potato puree of Agria and Marfona potato-cultivars, corn flour, emulsifier ,shortening, water,starch, salt, garlic and pepper powder were used. Dough was sheeted to thickness of 1-2 mm and formed to desirable shape. These slices were baked at 125oC for 30 minutes. Prepared potato chips were packed in air or nitrogen atmosphere and stored in dark at 25oC. Peroxide value, bending strength and color of the samples were determined in 30 day intervals. Peroxide value was detected just at the end of the third month. Peroxide value in chips packed in nitrogen atmosphere was less than that in chips packed in air atmosphere. Atmosphere of packages had a significant effect on the bending strength of the chips (p<0.01). The bending strength of chips packed in nitrogen atmosphere was more than that of chips packed in air atmosphere. Storage time had significant effect on bending strength (p<0.01). Storage time and cultivar effects on lightness and darkness of chips (L in hunter lab system) were significant (p<0.01). Storage time and cultivar effects on yellowness and blueness (b) of chips were significant (p<0.05). Storage time, cultivar and packaging atmosphere had no significant effect on redness and greenness (a) of chips (p<0.05)
A. Abdollah Zadeh, M. Shahedi,
Volume 11, Issue 40 (summer 2007)
Abstract
Lots of investigation has been done in order to increase wheat yield per acre in Iran, but there is not enough study about quality of produced wheat. Bread quality in Iran has been deteriorated in recent years, mostly due to employing wheat flours of low quality. Thus the present study was conducted to find the chemical and rheological properties of four bread wheat cultivars (Omid, Rosshan, Golestani and “Kal”) produced in Sabzavar region. The results indicated that the quantity and quality of “Kal” wheat gluten are more desirable in comparison to the other varieties. The rheological experiment results indicated that the Omid wheat flour is the best regarding the dough resistance coefficient and alfa amylase activity. The alfa amylase activity of all flours was low. Appropriate time for fermentation of bread dough for all flours was 75 to 90 minutes. Mixture of one to ten ratio of Roshan and Omid flour produced bread with better quality. The results also indicated that the rheological properties of “Kal” flour dough such as mixing resistance, breaking point resistance and valorimeter value are acceptable. The bakery properties of “Kal” flour is better than Rosham flour. The “Kal” variety of wheat is the same as Roshan variety and the only difference between them is the region of production and farming conditions. It shows that farming condition is one of the important factors affecting bread wheat quality.
R. Sadeh, M. Azar, M. Shahedi, M.t. Mazloomi,
Volume 11, Issue 41 (fall 2007)
Abstract
Homogenized milks at 0.5 and 2.5% fat content were each fortified with three levels of Vitamin A palmitate at 3000, 4000 and 5000 IU/L. Vitamin was added just before homogenization and then pasteurized milks were packed in polymeric pouches and glass bottles. All samples were refrigerated at 4-5 °C for 48 hours. Any reduction in vitamin A level was monitored using HPLC, while sensory evaluation was conducted in order to rank the samples. ANOVA and Friedman analyses indicated that fat content along with package type had a significant effect on the residue of vitamin A. The loss of vitamin A was significantly higher in 0.5% milk either packed in polymeric pouch or glass bottle. However, besides fat concentration, more vitamin A was lost in glass bottles rather than polymeric pouches. Sensory evaluation showed that milk fortification had no adverse effects on color and flavor of the product.
M. Ghanbari , M. Shahedi,
Volume 12, Issue 43 (spring 2008)
Abstract
Baking is obviously one of the most important stages of bread production. Baking time and oven temperature have greatest effects on bread quality. The aim of this study was to investigate the effect of baking time and temperature on bread quality and its shelf life. In this study, the effect of three rates of oven temperature (top and under bread surface) and baking time levels on bread quality and its shelf life was investigated. Baking temperature and time were 300 and 280 °C for 3 minutes and 20 seconds, 300 and 350 °C for 2 minutes and 30 seconds and 350 and 380 °C for 2 minutes respectively. Soluble starch and staling factors of the samples were measured. The data was statistically analyzed by complete randomized design and comparison was made between the means via Duncan,s multiple range test at 5% level. The results showed that the bread baked in various time–temperature conditions were different in moisture content. The bread baked at lower temperature and longer time had the lowest moisture. Also, the result showed that the amount of soluble starch increased by increasing the baking time and decreasing the baking temperature. The bread baked in various baking conditions showed significant differences in staling rates. Lower baking time and higher baking temperature caused the lowest bread staling rates.
M. Ghanbari , M. Shahedi,
Volume 12, Issue 43 (spring 2008)
Abstract
Effect of semihydrogenated vegetable oil (shortening) and sodium stearoyl lactylate (SSL) on retarding Barbari bread staling was investigated in this study. Three levels of 2, 3 and 4 percent shortening and SSL in two levels of 0.5 and 1 percent of flour were used in this research. Treatments included control sample (without shortening and SSL), bread with only shortening, bread with only SSL, and bread with 0.5 percent SSL and 3 percent shortening. Organoleptic properties and staling factors of the samples were determined. The data was statistically analyzed by complete randomized design and means comparison was done by Duncan’s multiple range test (5% level). The results showed that the breads containing SSL and shortening were significantly different in organoleptic properties, and samples with 0.5 SSL and 3 percent shortening had the highest quality. The results of staling test showed that samples with 0.5 percent SSL and 3% shortening had the lowest staling rates.
E Moharami, M Shahedi, M Kadivar,
Volume 13, Issue 47 (4-2009)
Abstract
Enzymes of wheat flour have an important role in production of various cereal products, especially bread, and therefore accurate measurement of enzymatic activity along with improvement of this characteristic is the basis of most studies in baking industry. In the present work, physical properties of three wheat varieties (Mahdavi, Kavir and M7318 that are cultivated in Isfahan province) and chemical characteristics of their flours were investigated. In order to study the changes in enzymatic activities (α-amylase, lipase and lipoxygenase), the activities of these enzymes were measured before and after germination. The relationship between root length and α-amylase activity was studied as well as the relation between lipase and lipoxygenase activities. α-amylase activity of flours was also optimized according to falling number 250 s. The effect of this optimization on the bread texture in four different times after baking, on the flour color in three different times, and on the flour acidity in two different times were then evaluated. The results of chemical measurements showed that M7318 and other two varieties can be considered as weak flours and medium flours, respectively, in terms of their protein and gluten contents. However, all varieties had low levels of α-amylase activity, although, kavir flour had more activity than the others. The results of germination tests indicated an increase in the activity of α-amylase and lipase, but not lipoxygenase. Moreover, during germination times a significant negative correlation between root length and falling number was found. Also, a significant positive correlation between root length and α-amylase activity and between activities of lipase and lipoxygenase was observed.
A Shaker Ardekani, M Shahedi, G Kabir,
Volume 13, Issue 47 (4-2009)
Abstract
Pistachio processing, such as production of pistachio butter, is one of the ways to increase the added value of pistachio. Pistachio butter is a paste containing mainly milled, roasted pistachio kernel and sugar. In this investigation, the effect of two emulsifiers (lecithin and mono-di glycerids) at three levels of 0.0, 1.0, 2.0%, on the oil leakage and the effects of BHT as an antioxidant at three levels of 0.00, 0.01 and 0.02% on the peroxide values of pistachio butter and paste after 4 months storage at 20 °C were studied. Each experiment was performed in triplicates. Rheological and organoleptic tests were performed on the finished products. The results were statistically analyzed by a completely randomized Design and by making comparisons between the means via multiple range Duncan's test (P <0.05). Roasting of the pistachios at 110°C for 15 min was the best condition as determined by taste panelists. Moreover, addition of 15-25% of sugar in butter formula, received the best score by the panelists. The results of organoleptic tests showed that the sample containing lecithin and mono-diglycerides had the least leakage of oil. Based on the results, pistachio butter produced in this investigation received higher score in terms of flavor and texture than industrial pistachio butter in the market. Results also showed that addition of BHT had a significant effect on shelf life of pistachio butter. Rheological experiments showed that pistachio butter produced in this investigation was 1.5 times softer than its industrial counterpart. The results indicated that the best formula for production of pistachio butter was 72.99 - 82.99 % roasted pistachio kernels, 15-25 % sugar, 1% lecithin, 1% mono di glyceride and 0.01 % BHT.
A Gholamhoseni Por, M.j Varidi, M Elahi, F Shahedi,
Volume 13, Issue 47 (4-2009)
Abstract
This research was carried out taking into consideration the defects of traditional process in and the most important factors affecting production of rock candy. Selected parameters used for effluent and rock candy consisted of supersaturation at 4 levels (1.3, 1.4, 1.5, and 1.6) and temperature at 3 levels (70, 80, 900C) with 3 replications. The physiochemical tests consisted of pH, color and invert sugar percentage done on all the samples. According to the results, the rise in super-saturation and temperature had significant effect on all the effluent and rock candy characteristics (P<0.01) such that color and invert sugar percentage increased and pH decreased as super-saturation and temperature increased. Furthermore, the interaction effect of super-saturation and temperature on pH, color and invert sugar percentage of rock candy was significant (P<0.01).
A Akbari, M Shahedi, N Hmadami, Sh Dokhani, M Sadeghi,
Volume 13, Issue 47 (4-2009)
Abstract
Sun drying is a well-known food preservation technique that reduces the moisture contents of agricultural products. Shrinkage, rehydration ability and color of food materials during air drying adversely affect the quality of the dried products. Since all fresh tomatoes can not be consumed at the time of harvest, preservation provides a larger market, allowing consumers to buy the preserved tomato through the year. A natural convection solar dryer consisting of a solar air heater and a drying chamber was manufactured in this research. Tomato slices were dried in the solar dryer and compared with open sun drying. Also, tomato slices were dried in a laboratory oven (operated at temperature 50, 60, 70, 80°C). With increasing the temperature, the time required to arrive certain moisture content is decreased. Also results showed that drying time in the solar dryer is shorter than open sun drying. In other words, drying time was reduced 17 to 45% by the solar drying in comparison to open – sun drying. The experimental shrinkage data showed a linear behavior with moisture content. Also, the experimental data didn't show a strong effect of temperature on the rehydration ability of the product. Thus, the effect of temperature and method of sun drying on the shrinkage phenomenon and the rehydration ability can be neglected. Tomato slices dried at 50°C had better appearance (lightness and red color) than at 80°C.
S. Zahedi, K. Shahedi, M. Habibnejhad Roshan, K. Solaimani, K. Dadkhah,
Volume 21, Issue 4 (Winter 2018)
Abstract
Soil depth is a major soil characteristic commonly used in distributed hydrological modeling in order to present watershed subsurface attributes. It strongly affects water infiltration and accordingly runoff generation, subsurface moisture storage, vertical and lateral moisture movement, saturation thickness and plant root depth in the soil. The objective of this study is to develop a statistical model that predicts the spatial pattern of soil depth over the watershed from topographic and land cover variables derived from DEM and satellite image, respectively. A 10 m resolution DEM was prepared using 1:25000 topographic maps. Landsat8 imagery, OLI sensor (May 06, 2015) was used to derive different land cover attributes. Soil depth, topographic curvature, land use and vegetation characteristics were surveyed at 426 profiles within the four sub-watersheds. Box Cox transformations were used to normalize the measured soil depth and each explanatory variable. Random Forest prediction model was used to predict soil depth using the explanatory variables. The model was run using 336 data points in the calibration dataset with all 31 explanatory variables (18 variables from DEM and 13 variables from remote sensing image), and soil depth as the response of the model. Prediction errors were computed for validation data set. Testing dataset was done with the model soil depth values at testing locations (93 points). The Nash-Sutcliffe Efficiency coefficient (NSE) for testing data set was 0.689. The results showed that land use, Specific Catchment Area (SCA), NDVI, Aspect, Slope and PCA1 are the most important explanatory variables in predicting soil depth.
M Rezaei Pasha, K Shahedi, Q. Vahabzadeh, A. Kavian, M. Ghajar Sepanlou, P. Jouquet,
Volume 23, Issue 2 (Summer 2019)
Abstract
One of the management practices to reduce the harmful effects of chemical fertilizers and to protect soil and water resources is applying a combination of organic and chemical fertilizers that can better than using them separately. Therefore, in order to understand and identify the effectiveness of this management practice, it is necessary to examine runoff and sediment production. This study was carried out in an agricultural sloping land located in the North of Iran, near Sari city. For this purpose, runoff measurement plots of 1 × 5 m were set up under natural rainfall based on a randomized block experimental design. Soil samples were measured at 0-10 and 10-20 cm depths. In this study, parameters such as runoff (volume, nitrate content, sediment yields), soil physical features (porosity and infiltration coefficient), and soil chemical properties (EC, OC, N, CEC, pH) were measured. The results showed that among soil chemical and physical properties, just N, EC and pH significantly influenced the Municipal Solid Waste Compost. A PCA was carried out, showing that these treatments explained 74.35% of the total variance of the results. Accordingly, it could be stated that using soil and water conservation management practices can rapidly significantly improve the soil properties in the sloping lands.
S. H. Roshun, K. Shahedi, M. Habibnejad Roshan, J. Chormanski,
Volume 25, Issue 2 (Summer 2021)
Abstract
The simulation of the rainfall-runoff process in the watershed has particular importance for a better understanding of hydrologic issues, water resources management, river engineering, flood control structures, and flood storage. In this study, to simulate the rainfall-runoff process, rainfall and discharge data were used in the period 1997-2017. After data qualitative control, rainfall, and discharge delays were determined using the coefficients of autocorrelation, partial autocorrelation, and cross-correlation in R Studio software. Then, the effective parameters and the optimum combination were determined by the Gamma test method and used to implement the model under three different scenarios in MATLAB software. Gamma test results showed that today's precipitation parameters, precipitation of the previous day, discharge of the previous day, and discharge of two days ago have the greatest effect on the outflow of the basin. Also, the Pt Qt-1 and Pt Pt-1 Qt-1 Qt-2 Qt-3 combinations were selected as the most suitable input combinations for modeling. The results of the modeling showed that in the support vector machine model, the Radial Base kernel Function (RBF) has a better performance than multiple and linear kernels. Also, the performance of the Artificial Neural Network model (ANN) is better than the Support Vector Machine model (SVM) with Radial Base kernel Function (RBF).
A. Zare Garizi, K. Shahedi, A. Matboo,
Volume 28, Issue 1 (Spring 2024)
Abstract
Water quality characteristics play a crucial role in water resources management, watershed health assessment, and implementing effective management strategies. The objective of this research was to present an overall assessment of the surface water quality in the Gorganrood River Basin to be utilized for developing effective watershed management plans and programs. Various physicochemical water quality data including main anions and cations, Total Dissolved Solids (TDS), Electrical Conductivity (EC), Sodium Absorption Ratio (SAR), pH, and total hardness recorded at 25 hydrometric stations across the basin were analyzed and assessed with the Canadian (CCME) Water Quality Index. The mean water quality index for drinking, agriculture, and industrial purposes indicated that headwaters and higher areas generally exhibited better water quality compared to the downstream areas of the basin. Geochemical processes and the introduction of various pollutants during water flow from the headwaters to the basin outlet contribute to a decline in water quality. The highest water quality was observed in the Kabudval and Shirabad stations, whereas the Baghesalian station exhibited the lowest. For drinking water use, hardness, bicarbonate, and chloride were identified as variables contributing to water quality decline in the headwaters and upstream areas. However, these areas predominantly maintained a moderate to good quality for drinking purposes. Conversely, downstream areas experienced a significant deterioration in water quality with higher pollutant levels such as total dissolved solids (TDS), sulfate, and sodium, resulting in relatively poor to poor conditions. Approximately 60% of the stations in the basin had excellent water quality for agricultural use, with no limiting factors. Only three stations near the basin's outlet exhibited relatively poor to poor water quality due to elevated chloride levels, sodium adsorption ratio (SAR), and electrical conductivity. only 28% of hydrometric stations demonstrated good water quality for industrial use. Hardness, pH, and TDS are the main variables contributing to water quality decline for industrial use in the upstream, while downstream areas are impacted by chloride and sulfate. The outcomes of this study hold significant implications for effective water resources management, watershed preservation, and natural resource conservation in the Gorganrood basin. From industry and especially health aspects, however, more detailed investigations are needed, taking into account some other important variables of water quality (including nitrate, total coliform, fecal coliform, etc.).
