Vahid Mohammadpour; Mohamad Taghi Hamed Mosavian
Abstract
Frying is an important unit operation used widely both in domestic and industrial cooking. Reduced pressure (vacuum), microwave, deep fat and pan frying are the most important methods of food frying. Final product has good organoleptic quality (colour, texture, and flavour). The accuracy of the knowledge ...
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Frying is an important unit operation used widely both in domestic and industrial cooking. Reduced pressure (vacuum), microwave, deep fat and pan frying are the most important methods of food frying. Final product has good organoleptic quality (colour, texture, and flavour). The accuracy of the knowledge of mass transfer parameters (effective diffusivity coefficient, dimensionless Biot number and mass transfer coefficient) in the case of frying is essential and important for designing, modeling and process optimization. This study is undertaken to develop a more realistic approach for determining mass transfer parameters during frying of potato slices for cylindrical coordinates. These parameters were evaluated from the plots of dimensionless concentration ratios against time in sunflower liquid oil at and . Effective diffusivity coefficient, dimensionless Biot number and mass transfer coefficient ranged between to , to and to , respectively. Effective diffusivity coefficient and mass transfer coefficient were found to increase with an increase in frying temperature, whereas Biot number decreased. An Arrhenius type of relationship was found between the frying temperature and effective diffusivity coefficient.
Nasser Valipoor Motlagh; Mohamad Taghi Hamed Mosavian; Seyed Ali Mortazavi
Abstract
In this research, attention is focused on the resistantance of packages containing silver nanoparticles to gases such as oxygen as well as to the antimicrobial property of these packages. The effect of these packages on increasing quality and shelf time of the barberry was investigated in comparison ...
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In this research, attention is focused on the resistantance of packages containing silver nanoparticles to gases such as oxygen as well as to the antimicrobial property of these packages. The effect of these packages on increasing quality and shelf time of the barberry was investigated in comparison with the current polyethylene packages. To do this, different microbial factors and the color of the barberry were investigated. The microbial experiments were done according to the national standards of Iran. The data obtained from microbial tests statistically considered by SPSS15 software. They showed decreasing microbial capacity, especially in the case of mold and counting total bacteria, packages containing silver nanoparticles had between 1% and 2% concentration of nanoparticles in comparison with the samples of polyethylene packages. Investigation of the apparent color of the samples was also done according to an average red color and brightness of the images taken from barberry seeds by Photoshop CS3 software, version10. The data obtained from these investigations statistically considered by SPSS15 software. The results showed that the apparent color is qualitatively better in the samples of packages containing 2% and 3% silver nanoparticles, compared with samples of polyethylene packages. However, a low concentration of nanoparticles, in the range of 200 part per million (ppm), did not produce a great effect on increasing either the quality or the shelf life in barberry, compared with ordinary polyethylene packages.
Keywords: Barberry, Nanosilver package, Silver nanoparticles, Microorganism, Antimicrobial property, Polyethylene
Effat Ghasemi; Mohamad Taghi Hamed Mosavian; Mohammad Hossein Hadad Khodaparast
Abstract
In this work, the effects of acetic and lactic acids addition to rice during cooking, on the texture and morphological properties, and too, the gelatinization temperature (GT) of the cooked Domsiyah rice was investigated. All experiments were carried out in triplicate and data analyzed in randomized ...
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In this work, the effects of acetic and lactic acids addition to rice during cooking, on the texture and morphological properties, and too, the gelatinization temperature (GT) of the cooked Domsiyah rice was investigated. All experiments were carried out in triplicate and data analyzed in randomized completely by SPSS15 software. The results showed that acid addition to rice during cooking cause a decrease in firmness and GT, but had no significant effect on adhesiveness of samples. Also, the results of the scanning electron microscopy on the outer surface of cooked rice kernel revealed that the acid's addition to rice during cooking cause a reduce in pore size and porosity. According to amylography and SEM results, it seems that acid's addition to rice during cooking, cause the better gelatinization and closer pores on the outer surface of cooked rice. The results of this research can be used in improving in quality attributes of cooked rice and other products that contain rice flour and rice starch, according to the aim and application of the desirable product.
Keywords: rice, cooking, acetic acid, lactic acid, gelatinization, texture, scanning electron microscopy (SEM).
Vahid Mohammadpour; Mohamad Taghi Hamed Mosavian; Ahmad Etemadi
Abstract
Knowledge of desorption kinetics is essential to predict the behavior of the material during drying
process and to design dryer equipment .The main objective of this study is to obtain the effective
diffusivity coefficient and activation energy of shelled pistachio. Another goal is to find drying
kinetics ...
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Knowledge of desorption kinetics is essential to predict the behavior of the material during drying
process and to design dryer equipment .The main objective of this study is to obtain the effective
diffusivity coefficient and activation energy of shelled pistachio. Another goal is to find drying
kinetics of shelled pistachio in fluidized bed dryer and so thin-layer characteristics of shelled
pistachios were determined experimentally as a function of temperature and air velocity .Accordingly,
6 mathematical models (Two term model, Exponential model, Logarithmic model, Page model,
Modified page model and Henderson & Pabis model) for describing the thin-layer drying behavior of
shelled pistachios were investigated. Tests were conducted using four air temperature (25,30,45 and 60
C) ,and three air velocities (6, 8 & 10m/s).Out of the 6 models considered ,the two term model were
considered to be the most suitable for describing the drying behavior of the shelled pistachios .Also,
for high air temperature and velocity, Henderson-Pabis model proved to be suitable .Results showed
that air velocity and operating temperature enhanced the kinetics of drying of shelled pistachio and the
drying air temperature had a great effect on the drying kinetics. By using of Fick’s second Law the
effective diffusivity coefficient and activation energy of pistachio was determined.
Keywords : Effective Diffusivity Coefficient, Activation Energy, Drying Kinetics, Fluidized Bed
Dryer, Pistachio Drying
