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Showing 11 results for Jahanbakhshi


Volume 0, Issue 0 (ARTICLES IN PRESS 2024)
Abstract

The present study investigates the effect of baking temperatures (140, 160, 180, 200, and 220℃) on texture kinetics. It also explores a statistical classification meta-algorithm, called Adaptive Boosting (AdaBoost), to predict texture changes during conventional cake baking. The experimental results indicated that texture properties were significantly affected by baking temperature and time. As time and temperature increased, there was an increase in hardness, cohesiveness, gumminess, and chewiness and a decrease in springiness. However, the impact of time and temperature on resilience was inconsistent, as it was maximum in the last quarter of the process. The predicted results revealed that the AdaBoost algorithm accurately predicted the texture properties with a high coefficient of determination (R2 > 0.989) and minimal root mean square error (RMSE < 0.0019) across all textural properties. Therefore, it can serve as an efficient tool for predicting the texture properties of cakes during baking. Furthermore, the proposed methodology can be extended to predict the texture properties of other baked goods.
 

Volume 1, Issue 1 (3-2013)
Abstract

This study was carried out to investigate alternative instead of corn gluten meal in diets and the effects of this substitution on blood biochemical and hematological parameters of common carp juvenile. Juvenile's carp with an average 11.5 ± 0.5g, 9 ± 1cm weight and length respectively, were fed with experimental diets for 8 weeks. Diets with 31% crude protein and 3100 kcal kg-1 raw energy alternative levels of 150, 270 and 490 (gr kg-1) and a control diet without corn gluten was made. At the end of the experiment, blood biochemical parameters, including glucose, cholesterol, triglycerides, and hemoglobin, hematocrit, white blood cells (WBC) and red blood cells (RBC) in juveniles fed the experimental diets compared with the control group showed a significant difference (P0.05). Also with replacement value of corn gluten in experimental diets, it was concluded that growth and nutritional factors treatments compared with control group significantly decreased (P

Volume 15, Issue 84 (2-2019)
Abstract

In this study the herdel effects of heating time, basil seed mucilage and Sodium Nitrite during preservating time on qualitative characteristics of 40% sausage by RSM method were investigated in order to decrease using nitrite at sausage. At first section the effect of different herdels on qualitative characteristics of sausage including residual nitrite, color and the number of Clostridium Perfringens and texure were investigated. In the second part, the optimization and the validity of developed model were performed. The results indicated that by increasing nitrite, the residual nitrite amount increased and by increasing of preservation time the nitrite amount was decreased. Overall changes are influenced by nitrite amount, basil seed mucilage, and heating time. Chlorostidium number was influenced by nitrite square and preservation time, so that the lowest Clostridium Perfringens amount was acquired at the highest nitrite concentration. Also only effective parameter on the sausage texture was basil seed mucilage. By increasing of mucilage content hardness of sausage was decreased by optimization the amounts of 95.38 ppm nitrite, 0.76% basil seed mucilage, the heating time of 112.15 minute at the preservation time of (24 days) were selected- which this formula lead to decrease at about 30ppm of the added nitrite- based on Iran national standard. The theoretical and the experimental results were in great agreement so RSM could be used for modeling and optimization of such processes.

Volume 16, Issue 88 (6-2019)
Abstract

The aim of this study was to determine the kinetics, effective moisture diffusivity, activation energy, specific energy consumption, and also predict the moisture content of white mulberry during the drying process with microwave-hot air dryer using mathematical models, Artificial Neural Networks (ANN) and Neuro-Fuzzy Inference System (ANFIS). Drying process was accomplished in three temperature levels (40, 55, and 70°C), three inlet air velocity levels (0.5, 1 and 1.5 m/s) and three microwave power levels (270, 450 and 630 W). To estimate the moisture ratio of white mulberry, 10 mathematical models, ANN and ANFIS were used to fit the experimental data of thin-layer drying. The results showed, the maximum and minimum effective moisture diffusivity during drying was calculated 3.56×10-9 and 3.86×10-10 m2/s, respectively. Also, the minimum and maximum effective moisture diffusivity during drying was achieved 48.54 and 1380.88 Mj/kg, respectively. Among the mathematical models under study, the Page model was the best model for describing the behavior of the thin layer of white mulberry drying. The mean square error (MSE) values for the mathematical models, ANN, and ANFIS were 0.00059, 0.0052 and 0.0044, respectively. Therefore, the ANFIS model with the highest Correlation Coefficient (R2=0.99995), the least percentage of mean relative error (ε=1.84) and mean square error (MSE=0.0044) were used to evaluate the moisture ratio in comparison with other methods implemented in this research Selected as the best model
Akram Jahanbakhshi, Afshin Ahmadi Nadooshan, Arash Shad, Mahsa Farzaneh,
Volume 17, Issue 3 (5-2017)
Abstract

In the present paper, the effect of fins presence on natural convection between coaxial annuli was investigated, numerically. The external duct was circular and the internal ducts included three circular, square, and triangular cross sections for discussed annuli. As a geometrical constrain, both cross section area and diameter of external duct of annuli were considered equivalent together for all investigated cases. The area of fins installed on the internal ducts was constant, and their effects on thermal behavior of annuli were compared with considering the constant wall temperature boundary condition for surfaces in the range of 105≤Ra≤108. The results showed that with increase of Rayleigh number and consequently velocity, the heat transfer coefficient was increased for both surfaces. However, presence of fins reduced the values of heat transfer coefficient of internal ducts about 50%, while they increased those values for external ducts. Also, in the case of circular annulus, with increase of Rayleigh number, the Nusselt number wincreased about 71% and 64% for non-finned and finned ones, respectively. As a result, fins increased the overall heat transfer rate of both surfaces of annuli about 13% in comparison of non-finned surfaces.
Akram Jahanbakhshi, Afshin Ahmadi Nadooshan,
Volume 17, Issue 11 (1-2018)
Abstract

In this paper, natural convection heat transfer is numerically investigated in a square enclosure filled with power law non-Newtonian fluid model and central heat source for steady and quiet state. The top wall of the enclosure is thermally insulated and the vertical walls are at constant temperature of TC. The down wall of the enclosure also has four equal parts at constant temperature of TC and TH. The governing equations for the power-law fluid flow are solved with the numerical finite difference method based on the control volume formulation and SIMPLE algorithm. The results show that for small Rayleigh numbers the Nusselt number will not be affected by changes of the power law index but in Ra=106, thermal performance changes are more significant with the change in power law index. With a smaller the Rayleigh number in all indexs, the center of flow lines rotation, regarding to the axis parallel to axis Y, in the middle of the enclosure, will be more symmetrical. Also with stronger natural convection in the square enclosure, the average of Nusselt number for non-Newtonian fluid increase with increased power law index and improved thermal performance by increasing the Rayleigh number is impressive for the density power law fluid (n˃1). Results also show that the Rayleigh number for the start of natural convection in the square enclosure is reduced by increasing the power law index.
Akram Jahanbakhshi, Afshin Ahmadi Nadooshan,
Volume 18, Issue 2 (4-2018)
Abstract

In this paper, the interior air of the room heated by the solar wall (Trombe) with respect to Heat conduction in the wall is numerically simulated. Momentum and energy equations have been Algebraic with finite volume method and at the same time are solved with SIMPLE algorithm. First, a reference model is introduced and the results are presented and then with this reference model, the effective parameters on the performance of the wall were investigated and ultimately the most optimal geometry for the solar wall with the best performance was voted.As well, rectangular fins has been put on the surface of the absorbent wall, in order to increase its efficiency. The results show that solar wall with rectangular fins in all air gaps has better performance than plain wall and for example, with rectangular fins in the air gap equal to 1 m, room temperature is approximately 1.24% more than the simple Trombe wall. Then, using Artificial Neural Networks and ANFIS the values increase of room temperature by increasing the number of fins has been projected on the wall. The neural network was trained in such a way that the average temperature of the room depends on the number of fins on the surface of the absorbent the solar wall. The results compare mean squared error and root-mean-square error showed that ANFIS With the mean squared error equal to 0.742599 has good performance and acceptable accuracy compared with Neural Network With the mean squared error equal 1.1 to predict temperature.

Volume 18, Issue 118 (December 2021)
Abstract

Enzymatic treatment of wheat flour is an interesting function to improve its functional properties. Because enzymes with different biochemical activities can have synergistic effects on dough behavior or product quality, the individual use and combination of enzymes used in bread production processes is important today. The aim of this study was to evaluate the synergy of glucose oxidase and lipase enzymes in physicochemical properties of barberry flour and bread formulated with relative replacement of corn flour. Treatments in 7 groups (T0 control sample, T1 containing 5% corn flour 0.05% glucose oxidase 0.05% lipase, T2 containing 10% corn flour 0.07% glucose oxidase 0.07% lipase, T3 containing 15% flour Corn 0.09% glucose oxidase 0.09% lipase, T4 contains 20% corn flour 0.011% glucose oxidase 0.011% lipase, T5 contains 25% corn flour 0.13% glucose oxidase 0.13% lipase, T6 Containing 30% corn flour (0.15% glucose oxidase (0.15% lipase) were prepared).
 The chemical results of the treatments showed an increase in moisture, ash and gluten index so that the highest amount of the mentioned factors was observed in T6 sample. Zellini number, phallus number, protein and gluten showed a significant decrease.  Farinograph test results showed no significant water uptake, reduced spreading time and resistance with increasing corn flour replacement percentage in the treatments. The tensile strength of the treatments in the extensograph test showed an increase and a decrease in tensile strength and tensile strength of the treatments, respectively (p<0.05).
 Histological results showed that the use of lipase enzyme and corn flour reduces the stiffness of the treatments. While the addition of corn flour caused the doughs to stick and the enzymes were ineffective. The elasticity of the doughs was also improved by the addition of glucose oxidase. The results of sensory evaluation introduced T4 treatment as the superior treatment.

Volume 19, Issue 132 ( February 2023)
Abstract

In the present study, the properties of polylactic acid marker film combined with red cabbage and beet anthocyanins were investigated. There were four samples: 1 (polylactic acid without anthocyanins), 2 (polylactic acid containing red cabbage anthocyanins), 3 (polylactic acid containing beet anthocyanin) and 4 (polylactic acid containing beet anthocyanin and red cabbage). Thickness, solubility, mechanical properties and changes in color indices were analyzed. The results showed that there were no statistically significant differences in the thickness of the film samples (p> 0.05). The highest solubility belonged to the sample 1 and the minimum solubility was detected insample 4. The highest increase in elongation at break was seen in samples 3 and 4 and the lowest increase in elongation at break belonged to sample 1 (p≤0.05). In all the films except sample 1, by pH rise (up to pH = 14), L * factor increased significantly (p≤0.05). In all pH ranges, sample 1 had the highest L * and sample 3 had the lowest one (p≤0.05). a * indice in sample 3, at pH = 1-6, had an increasing trend and then decreased to pH = 14 (p≤0.05). In samples 2 and 4 at pH = 1-13, a decreasing trend was observed and then up to pH=14 an increasing trend was observed (p≤0.05). For b *in sample 2 there was a decline at pH = 1-12, then up to pH = 14, an increasing trend was detected (p≤0.05). The b * of sample 3 and 4 had a fall until pH=11 and 12 respectively following an increasing trend up to pH=14 (p≤0.05). The best sample was sample 4 due to suitable physical properties and clearer color changes at different pH.
 


Volume 22, Issue 158 (April 2025)
Abstract

:. In this study, the effect of pH, acidity, moisture content, reheating time, reheating drop as well as sensory evaluation at different thicknesses of chicken pieces (1.5, 2 and 2.5 cm) and different reheating temperatures (150 and 230 ° C) in chicken feed The kebab was examined. The results showed that with increasing the thickness of the chicken pieces and increasing the reheating temperature from 150 to 230 ° C, the reheating time increased but its value did not exceed the standard range (2 hours) and its maximum value was 2.5 cm thick and the temperature 150 ° C was observed for 18.58 minutes. Also, with increasing the thickness of chicken pieces and increasing the reheating temperature to 230 ° C, due to the decrease in surface moisture and dryness, the taste characteristics were more damaged and less acceptable in terms of taste, and  when chicken pieces were 1.5 cm at 150 ° C reheating had the highest quality in sensory evaluation with a score of 8.38. With increasing the thickness of chicken pieces and increasing the reheating temperature, the pH increased and the highest value was observed at 2.5 cm thickness and 230 ° C. In contrast, the acidity was decreased and the lowest was observed at a thickness of 2.5 cm at 230 ° C at 1.51. It should be noted that the moisture content of chicken parts with increasing thickness (2.5) and increasing the temperature to 230 degrees tended to the highest value of 38.04% and the lowest moisture content at 150 ° C was 34.36%. The results also showed that with increasing the thickness of chicken pieces, the heat loss decreased and this factor tended to the highest value of 0.968 at 150 ° C.

Volume 26, Issue 3 (5-2024)
Abstract

Ascorbic Acid (AsA) is a water-soluble antioxidant that makes plants resistant to environmental stresses by neutralizing free radicals. However, it is unknown to what extent this antioxidant may help Improve Irrigation Water Use Efficiency (IWUE) and reduce the adverse effects of water deficit on mung bean growth and yield. In an attempt to clarify whether exogenous application of this antioxidant could alleviate the adverse effects of water deficit on mung bean plants, two seasons (2019 and 2020) of field experiments were conducted using twelve combinations of three AsA levels (distilled water as a control and 10 and 20 mM of AsA) and four irrigation water amounts (25, 50, 75, and 100% of the plant water requirement). Based on the results, the maximum IWUE was obtained with W50AsA20 in the two seasons. The beneficial effect of AsA application on IWUE was determined under water stress conditions (W50). High water deficit (W50) plus applying 20 mM ascorbic acid, i.e. W(50)AsA(20) treatment, improved seed yield about 43.7% as in the two seasons compared to high water deficit without ascorbic acid, i.e. W(50)AsA(0). In 2019 and 2020, water saving in W(50)AsA(20) compared to the control, was equal to 50% (2,550 and 2,500 m3 ha-1, respectively). In W(50)AsA(20) treatment, the increase of seed yield ranged between 79-107% in both seasons. Thus, the results reveal the potency of AsA to save water under low water supply and increase yield in mung bean fields.

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