Research Article
Fatemeh Heydari; Mohammad Javad Varidi; Mehdi Varidi
Abstract
The objective of this study was the evaluation of pH, Color parameters [lightness (L*), redness (a*), yellowness (b*), chroma (C*), hue (H*), a*/b* ratio, and color differences (ΔE)], Mb, MetMb, OxyMb, DeoMb and WHC in minced meat. Three types of meat ( Beef, camel and ostrich) and four mincing ...
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The objective of this study was the evaluation of pH, Color parameters [lightness (L*), redness (a*), yellowness (b*), chroma (C*), hue (H*), a*/b* ratio, and color differences (ΔE)], Mb, MetMb, OxyMb, DeoMb and WHC in minced meat. Three types of meat ( Beef, camel and ostrich) and four mincing processes (three using a grinder with 7.5, 4 and 3 mm diameter holes in the plate, and a fourth in which a cutter was used to obtain a finely minced product) were studied. The intact meat was used as the control. Significant differences were observed in the pH, Color parameters [lightness (L*), redness (a*), yellowness (b*), chroma (C*), hue (H*), a*/b* ratio, Mb, MetMb, DeoMb and WHC of various types of meat (P 0.05). WHC and chroma showed statistically significant differences (P 0.05) for the mincing treatment. The ΔE and OxyMb showed no significant differences (p>. 0.05) for mincing and also in meat types. High correlation between pH and L* (R2=0.999), pH and WHC (R2=0.997) confirms the decrease in L* and increase in WHC along with increase in pH.
Research Article
Reza Farahmandfar; Seyed Ali Mortazavi; Farideh Tabatabaei Yazdi; Arash Koocheki
Abstract
In this study, variations of the pasting properties, swelling power and solubility of two rice starches, low amylose (8.7%) and high amylose (26%) at two citric acid concentrations (0 and 0.01 M) was investigated. The results showed that the peak viscosity and breakdown viscosity of rice starch decreased ...
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In this study, variations of the pasting properties, swelling power and solubility of two rice starches, low amylose (8.7%) and high amylose (26%) at two citric acid concentrations (0 and 0.01 M) was investigated. The results showed that the peak viscosity and breakdown viscosity of rice starch decreased significantly (P<0.05) with increased the proportion of amylose while hot past viscosity and cold past viscosity increased significantly (P<0.05). As the concentration of citric acid increased, pasting properties decreased but did not change (P>0.05).The swelling power and solubility of both starch pastes with and without citric acid increased with the increase of the temperature. As the concentration of citric acid increased, swelling power of low and high amylose starch decreased and this event was clearer in low amylose samples. On the other hand, citric acid induced solubility of samples particularly in high amylose rice starches. Furthermore, the swelling power and solubility of treatments decreased and increased with increasing amylose content of rice starch, respectively.
Research Article
Hamed Hosseini; Mohammad Ghorbani; Alireza Sadeghi Mahoonak; Yahya Maghsoudlou
Abstract
An accelerated shelf-life test using elevated temperatures 62, 72 and 82 ˚C was conducted to predict the oxidation progression of walnuts over a long-term storage. Oxidation parameters including values of conjugated dienes (CD) and trienes (CT) values and thiobarbituric acid (TBA) value were employed ...
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An accelerated shelf-life test using elevated temperatures 62, 72 and 82 ˚C was conducted to predict the oxidation progression of walnuts over a long-term storage. Oxidation parameters including values of conjugated dienes (CD) and trienes (CT) values and thiobarbituric acid (TBA) value were employed to evaluate the oxidation processes. Changes followed an apparent first-order kinetic. Walnuts and walnut kernels were also kept in normal condition (20-30˚С; RH, 35-45%) for 12 months in order to validate the approach. A maximum of energy (62.24-75.67 kJ mol-1 K-1) needed for formation of primary oxidation products and a minimum of energy (35.65 kJ mol-1 K-1) to generate secondary oxidation products were calculated. Formation of oxidation products in walnut kernels was found to be a temperature-dependent reaction, with Q10 =1.44- 2.1. The results showed that CD and CT values could provide a proper estimation for oxidative stability of the nuts stored in ordinary condition, with an average error of approximately 12.9%.
Research Article
Hadi Bagheri; Mohebbat Mohebbi; Arash Koocheki
Abstract
The effect of wheat-sorghum flour ratio (0, 25, 50, 75 and 100%) on viscoelastic and farinographic behaviour of dough was investigated. Constants of Peleg - Normand model and the stress relaxation (% SR) was calculated for the variables and the correlation between farinograph characteristics and stress ...
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The effect of wheat-sorghum flour ratio (0, 25, 50, 75 and 100%) on viscoelastic and farinographic behaviour of dough was investigated. Constants of Peleg - Normand model and the stress relaxation (% SR) was calculated for the variables and the correlation between farinograph characteristics and stress relaxation test parameters were evaluated. The results showed that with increasing the ratio of sorghum in flour, the amount of initial force (F0), mixing tolerance index and the stress relaxation (% SR) increased. However, the rate of water absorption, dough stability and Peleg - Normand model parameters (K1 and K2) decreased with increasing substitution of sorghum flour. Survey results showed that the correlation between the parameters of water absorption, dough stability and K1 and K2 was a highly positive. The stress relaxation (% SR), mixing tolerance index and the initial force (F0) had also positive correlations. With increasing substitution of sorghum flour, dough indicated the liquid-like viscoelastic behavior. Fitting the experimental data with the model showed the efficiency of Peleg - Normand model at high strain (10%).
Research Article
Ghasem Yousefi; Zahra Emam-Djomeh
Abstract
The present research surveyed the effect of five factors including: microwaves power, air temperatures and its flow rates, microwaving time onset and amount of substances on the requested time and energy for combined fluidized bed- microwaves drying of black raspberry into 50% dry base wet content. Response ...
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The present research surveyed the effect of five factors including: microwaves power, air temperatures and its flow rates, microwaving time onset and amount of substances on the requested time and energy for combined fluidized bed- microwaves drying of black raspberry into 50% dry base wet content. Response surface methodology and Central composite was used as experimental design. Multiple linear regression was used for obtaining second polynomials models for each analyses followed by ANOVA analysis in order to confirming the adequacy and accuracy of resulted models. Using the empirical resulted model the relationship between variables and responses were determined via response surface method. Correlation coefficients of the regression models were 0.964 and 0.970 respectively for the drying time and energy consumption. The Optimized drying condition were including; 600 watts for microwaves power and microwaving onset from that time as the moisture content was 344% decreased,73 g for amount of substances, and 85˚C and 15 m.s-1 for air temperatures and its flow rates respectively. Under mentioned conditions, the fitted model was predicted 52.66 Min and 65.2 Kj respectively for the requested drying time and energy consumption at combined drier. As a conclusion, the results showed that requested drying time and energy consumption were decreased with increasing of temperatures, microwaving time and its power, and decreasing of air flow rates. In this regard, the drying kinetics curve samples were drawn under the conditions listed that showed drying time is reduced to 76% with increasing temperature from 55 to 85 and use the microwave reduced drying time until 30 to 80%.
Research Article
Hadi Almasi; Babak Ghanbarzadeh; Jalal Dehghan nia; Ali Akbar Entezami; Asghar Khosrowshahi Asl
Abstract
Fatty acid modified cellulose nanofibers (MCNFs) and TBHQ antioxidant were added to poly(lactic acid) (PLA) film. The combined effects of the MCNFs and TBHQ on the morphological, thermal, mechanical and barrier properties of PLA film were analyzed. The morphology of fracture surfaces evaluated by field ...
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Fatty acid modified cellulose nanofibers (MCNFs) and TBHQ antioxidant were added to poly(lactic acid) (PLA) film. The combined effects of the MCNFs and TBHQ on the morphological, thermal, mechanical and barrier properties of PLA film were analyzed. The morphology of fracture surfaces evaluated by field emission scanning electron microscopy (FE-SEM). XRD results showed that the crystallinity of the PLA film with added MCNFs was substantially higher than that of pure PLA and antioxidant active PLA films. Glass transition and melting temperatures changed with the addition of these two components. The addition of 3wt% of TBHQ to PLA films leads to a significant reduction (p
Research Article
Mahdi Barmour; Jalal Dehghan nia; Babak Ghanbarzadeh
Abstract
The objective of this study was to evaluate the effect of process conditions and different pretreatments including ultrasound, microwave and osmotic dehydration on mass transfer and oil uptake during deep fat frying of potato slices. Ultrasound pretreatment was performed at frequency of 40 KHz for 10 ...
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The objective of this study was to evaluate the effect of process conditions and different pretreatments including ultrasound, microwave and osmotic dehydration on mass transfer and oil uptake during deep fat frying of potato slices. Ultrasound pretreatment was performed at frequency of 40 KHz for 10 and 30 minutes, microwave pretreatment was conducted at 5 W/g power and osmotic dehydration pretreatment was done in NaCl solutions with concentrations of 1 and 3 percent. Potato slices were then fried at 150, 170 and 190°C for 90, 180, 270 and 360 seconds. The results showed that ultrasound pretreatment for 10 minutes increases oil uptake of samples as compared with control sample, but when samples were exposed to ultrasound for 30 minutes, oil uptake was decreased. In addition, microwave pretreatment reduced oil uptake of potato slices insignificantly. Furthermore, osmotic dehydration pretreatment reduced oil uptake. In order to model oil uptake, experimental data were fitted with 6 models. The aforementioned models had the highest R2 and a minimum value of RMSE.
Research Article
Soudabeh Einafshar
Abstract
Sour cherry is one of the most important horticultural products in Iran that consumes as fresh and dried fruit. In this research the effect of osmotic pretreatment on Physicochemical, antioxiative and microbial characteristics of 4 cultivars of sour cherry: Early Jibilium, Butermo, Sigany and Local were ...
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Sour cherry is one of the most important horticultural products in Iran that consumes as fresh and dried fruit. In this research the effect of osmotic pretreatment on Physicochemical, antioxiative and microbial characteristics of 4 cultivars of sour cherry: Early Jibilium, Butermo, Sigany and Local were investigated. The samples were placed in different osmotic solution, dried and vacuum packed in Polyamide pouches The physicochemical tests (pH, Bx, titrable acidity, moisture content, color, anthocyanin and phenolc compounds and antioxidative activities) and microbial tests were carried out after 6 and 12 months. The results showed that sour cherry Butermo var. had the most Bx, pH, acidity. Local and Early Jibelium var. had the least Bx and ph. The amount of moisture of Early Jibelium and Local var. were the most and the least, respectively. The chroma of Local var. was the most and had the more red purity than other varieties. Butermo and Local var. with 28.8 and 23.35 mg Cyanidin 3 Glychoside had the most and the least anthocyanins respectively. The amount of total phenolic compounds in Butermo Var. was significantly more than other varieties. The reducing power of Early Jibelium var. was the more significantly than other varieties. Osmosis process had no effect on the moicrobial growth, anthocyanins and phenolic compounds and antioxidative activities. One year storage significantly increased moisture, color, microbial growth, phenolic compounds and radical scavenging power of dried cherries but had no effect on other factors. The microbial conditions of samples were on the standard limits.
Research Article
Sepideh Amirabadi; Arash Koocheki; Mohebbat Mohebbi
Abstract
In this research, different concentrations of xanthan and Lepidium perfoliatum seed gums (0.1, 0.2 and 0.3%) were used to improve the quality and shelf-life of chiffon cake. For this purpose, specific gravity and apparent viscosity of batter, and the volume, specific volume, moisture, sensory and texture ...
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In this research, different concentrations of xanthan and Lepidium perfoliatum seed gums (0.1, 0.2 and 0.3%) were used to improve the quality and shelf-life of chiffon cake. For this purpose, specific gravity and apparent viscosity of batter, and the volume, specific volume, moisture, sensory and texture properties, crumb and crust color were examined. To investigate the effect of gums on the shelf-life, all cakes were stored for sixth days. Results showed that there were a positive correlation between viscosity of batter and cake volume. Both gums improved chiffon cake properties after removing from the oven and during storage. It was found that using 0.1% xanthan gum increased the cake volume, cohesiveness and sensory scores, decreasing firmness and moisture loss during storage of cake.
Short Article
Simin Gholami-Avarashk; Javad Sargolzaei
Abstract
Black nightshade is a weed plant that grows abundantly in most parts of Iran. In this study, central composite response surface method to investigate the effect of temperature 35-55 °C and pressures 170-350 bar during the dynamic time of 120 min, the particle size of 150 microns and flow rate of ...
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Black nightshade is a weed plant that grows abundantly in most parts of Iran. In this study, central composite response surface method to investigate the effect of temperature 35-55 °C and pressures 170-350 bar during the dynamic time of 120 min, the particle size of 150 microns and flow rate of 3 liters per minute on the efficiency of oil extracted from the fruits of black nightshade and optimizing operation of the extraction process using supercritical carbon dioxide was used. Extraction with an organic solvent hexane was chosen as a comparison. Based on the results, operating parameters including both pressure and temperature and their quadratic effects as well as the interaction between two parameter significant effect on the rate of extraction of oil(P
