Mohammad Bagher Habibi Najafi; Mohebbat Mohebbi; Fakhri Shahidi; Seyed Ali Mortazavi
Abstract
The effect of pretreatment osmotic-ultrasonic dehydration on the drying kinetic, rehydration kinetic, texture, shrinkage and color change of quince slices was investigated. Quince slices were osmotic-ultrasonic processed at 27.25 min for ultrasonic time, 120 min for osmotic dehydration and 50.52 % for ...
Read More
The effect of pretreatment osmotic-ultrasonic dehydration on the drying kinetic, rehydration kinetic, texture, shrinkage and color change of quince slices was investigated. Quince slices were osmotic-ultrasonic processed at 27.25 min for ultrasonic time, 120 min for osmotic dehydration and 50.52 % for sucrose concentration. The un-treated and pre-treated samples were then dehydrated at80°C. The effective diffusivity calculated by applying the Fick’s diffusion model. The pretreatment caused a decrease in Deff. Application of osmotic-ultrasonic dehydration reduced the sample hardness, color changes and shrinkage while it had increased the sample springiness, and chewiness.
Esmail Khazaei; Fakhri Shahidi; Seyed Ali Mortazavi; Mohebbat Mohebbi
Abstract
In this research, the production of a new kiwi- based product by applying kiwi puree, agar (0.25, 0.5 and 1%), guar (0.25, 0.5 and 1%) and other formulation ingredients (kiwi puree, sweeteners and pH modulators) has been investigated. Dependent variables include moisture content measurement, instrumental ...
Read More
In this research, the production of a new kiwi- based product by applying kiwi puree, agar (0.25, 0.5 and 1%), guar (0.25, 0.5 and 1%) and other formulation ingredients (kiwi puree, sweeteners and pH modulators) has been investigated. Dependent variables include moisture content measurement, instrumental texture analysis and sensory evaluations were carried out in a factorial design and the means were compared at significance level of 5 % by Duncan test. The results indicated that guar had a significant effect on the moisture content of final product. Textural properties of the kiwi pastille were influenced by the type and amount of hydrocolloids. Synergistic effects of agar and guar on the textural properties were also observed. While all products were acceptable regarding sensory properties, the samples prepared with 1% agar and 1% guar obtained the highest score.
Ahmad Ehtiati; Fakhri Shahidi; Mohebbat Mohebbi; Masoud Yavarmanesh
Abstract
SMP was substituted by WPC in four levels for preparing reconstituted milk. Two ropy and one nonropy starter cultures was used for Doogh preparation. Yield stress, viscosity, consistency index and pseudoplastic behavior of Doogh increased by increasing WPC content. Results showed that WPC increased colloidal ...
Read More
SMP was substituted by WPC in four levels for preparing reconstituted milk. Two ropy and one nonropy starter cultures was used for Doogh preparation. Yield stress, viscosity, consistency index and pseudoplastic behavior of Doogh increased by increasing WPC content. Results showed that WPC increased colloidal particles dimension and constructed a network which led to a decrease in Doogh phase separation (%32 at the highest level of WPC) during storage. Starter type had no effect on the Doogh stabilization. It does not have any effect on the studied physical properties in the presence of WPC, as well. Adding WPC to milk leads to improve of physical properties and stability of Doogh but using EPS producing starter cultures requires further studies in this field.
Elham Ansarifar; Mohebbat Mohebbi; Fakhri Shahidi; Mehdi Varidi
Abstract
The objective of this study was to evaluate the effect of frying temperature, time and different batter formulations on the rheological properties and mass transfer during deep fat frying of Kurdish cheese nuggets. The effects of white egg (0, 5, 10%) addition to the batter formulation of cheese nuggets ...
Read More
The objective of this study was to evaluate the effect of frying temperature, time and different batter formulations on the rheological properties and mass transfer during deep fat frying of Kurdish cheese nuggets. The effects of white egg (0, 5, 10%) addition to the batter formulation of cheese nuggets and frying at 150, 170 and 190◦C for 0, 1, 2, 3 and 4 min have been investigated. The results showed an interaction effect of these processing conditions on mass transfer. The most reduction in fat absorption was observed when samples were coated with batter containing 10% white egg and fried at 150 ◦C. The kinetic model based on the Fick’s law was used to describe moisture transfer data. The effective moisture diffusivity of batter without white egg was within the range of 3.97×10−8 and 7.51×10−8m2/s with R2 between 0.91 and 0.86 .In the samples coated with the batter including white egg, the effective diffusivity ranged between 2.26×10−8 and 5.96×10−8m2/s with R2 between 0.98 and 0.87, and fat transfer rate constant was between 1.1×10−3 and 8.9×10−3 s−1 with R2 from 0.82 to 0.99. Activation energy obtained from the Arrhenius plot for the effective moisture diffusivity of batter with and without white egg was 30.01 kJ/mol and ranged from 38.42 to 36.52 kJ/mol, respectively
Roya Rezaee; Fakhri Shahidi; Mohammad Elahi; Mohebbat Mohebbi; Mehdi Nasiri mahalati
Abstract
In this research, the production of plum pastille-like with starch and gelatin was studied. Thirteen formulation of plum pastille-like were prepared according to a second-order composite rotatable design (with five central points). Response surface methodology (RSM) was used to optimize product formulation ...
Read More
In this research, the production of plum pastille-like with starch and gelatin was studied. Thirteen formulation of plum pastille-like were prepared according to a second-order composite rotatable design (with five central points). Response surface methodology (RSM) was used to optimize product formulation with: gelatin concentration ranging from 3.85 to 6.925 % (w/w), and starch concentration ranging from 0 to 3.85 % (w/w) as independent variables. The dependent variables were texture objective evaluation and total acceptance obtained from sensory analysis. The texture and flavor attributes of the samples were identified and evaluated by a trained descriptive panel. The thickeners strongly affected texture and flavor attributes of the samples. The resulting polynomial equation (R2=0.9325) revealed that a formulation with 5.38% gelatin and 3.85% starch had a maximum total acceptance.
Fakhri Shahidi; Mohebbat Mohebbi; Mohammad Noshad; Ahmad Ehtiati; Milad Fathi
Abstract
Banana is one of the most important tropical fruit from commercial and industrial point of view. This fruit is an extremely perishable fruit which can not be preserved using freezing process. Therefore, drying is the most promising method. Conventional air drying is energy intensive and consequently ...
Read More
Banana is one of the most important tropical fruit from commercial and industrial point of view. This fruit is an extremely perishable fruit which can not be preserved using freezing process. Therefore, drying is the most promising method. Conventional air drying is energy intensive and consequently expensive method. Pre-treatments can be used to reduce the initial water content or to modify the fruit tissue which will result in higher yield with lower costs. In this research, the effect of osmotic dehydration and ultrasonic pre-treatment variables prior to air drying of bananas, including the type of solution (Glucose, Sucrose), time of immersion in osmotic solution (30, 45, 60 min), solution concentration (Brix 30 and 50), ultrasonication time (10, 20, 30 min) on water loss, solid gain, shrinkage, effective diffusivities and color in the process were studied. Results showed that the highest rate of water loss and solid gain and also the lowest rate of shrinkage were obtained in both pre-treatments when 50% glucose concentration was applied. The results indicated that unlike ultrasonication, osmotic pretreatment had a significant effect on color parameters of dried bananas.
Keywords: Banana, Drying, Image processing, Osmotic dehydration, Qualitative characteristics, Ultrasound
Safie Khalilian; Fakhri Shahidi; Mohammad Elahi; Mohebbat Mohebbi; Majid Sarmad; Mansoureh Roshan Nejad
Abstract
In this study the effect of different levels of xanthan and pectin on water activity and sensory properties of fruit pastille formulation based on Cantaloupe puree has been studied. The effects of xanthan (0, 0.1, 0.2, 0.3 %) and pectin (0.2, 0.3, 0.4, 0.5 %) were analyzed in a completely randomized ...
Read More
In this study the effect of different levels of xanthan and pectin on water activity and sensory properties of fruit pastille formulation based on Cantaloupe puree has been studied. The effects of xanthan (0, 0.1, 0.2, 0.3 %) and pectin (0.2, 0.3, 0.4, 0.5 %) were analyzed in a completely randomized design with factorial experiment. Results of ANOVA revealed that different levels of xanthan, pectin and interaction effects between pectin and xanthan had significant influence on water activity of cantaloupe pastilles (p≤0.05). The effects of pectin and xanthan were evaluated on sensory attributes by using multivariate variance analysis (MANOVA). Generally, only pectin level significantly changed (Hotelling Trace = p≤0.05) the sensory attributes. Pectin showed significant influence (p≤0.05) on color intensity, flavor color and appearance acceptance of pastilles. Xanthan had significant effect (p≤0.05) on color intensity and surface adhesivness. Pectin-xanthan interactions also showed significant influence (p≤0.05) on color intensity and stiffness of pastilles. Results of PCA determined that texture and flavor properties were more important than appearance attributes on total acceptance of cantaloupe pastille.
Keywords: Fruit pastille, Cantaloupe, Sensory properties, Water activity, Principal Component Analysis
Arash Koocheki; Fakhri Shahidi; Seyed Ali Mortazavi; Mahdi Karimi; Elnaz Milani
Abstract
The effect of xanthan and Qodume shirazi seed gum on fresh bread quality and its influence on dough rheology were studied. Incorporation of 0.3 to 1% of these two gums was investigated to evaluate its effect on the Mixing tolerance index (MTI), dough development time (DDT), gelatinization temperature ...
Read More
The effect of xanthan and Qodume shirazi seed gum on fresh bread quality and its influence on dough rheology were studied. Incorporation of 0.3 to 1% of these two gums was investigated to evaluate its effect on the Mixing tolerance index (MTI), dough development time (DDT), gelatinization temperature (GT), viscosity, dough stability and quality of wheat flour. Addition of xanthan and Qodume shirazi seed gum increased the water absorption, viscosity and dough stability. In contrast, MTI and GT decreased with increase in gum concentration. DDT remained statistically unaffected by all the levels of gum. There was increase in softness of bread with increase in the level of these gums up to 1%. Hardness values indicated that the breads containing xanthan gum was softer than the one with Qodume shirazi seed gum. However, Qodume shirazi seed gum could also improve these qualities so that it could be used as a new source of hydrocolloid in bread.
Keywords: Bread, Gum, Alyssum homolocarpum seeds, Rheology, Hardness
Mahsa Deylami; Nasser Sedaghat; Fakhri Shahidi
Abstract
Compressed biscuits (CBs) were developed using wheat flour, soy flour, sugar, oil and malt extract. Combining of compression and dehydration technology were applied for production. Packaging CBs using vacuum packaged, use of oxygen absorber (OA) and identical samples were aerobically packaged and stored ...
Read More
Compressed biscuits (CBs) were developed using wheat flour, soy flour, sugar, oil and malt extract. Combining of compression and dehydration technology were applied for production. Packaging CBs using vacuum packaged, use of oxygen absorber (OA) and identical samples were aerobically packaged and stored at ambient and elevated (40°с) temperature for 12 weeks. The effect of different packaging and temperature on chemical (FFA, peroxide value, aw and pH) and sensory (taste, texture and overall acceptability) characteristics of CBs was examined during storage. Free fatty acid (FFA) values showed no significant differences for all packaging treatments. According to peroxide values (PV) oxidation rate in aerobically packed CBs was the highest. These data suggest that OA were effective in prolonging the lag time before the PV started to build up. During storage a decrease in aw and pH values and an increase in FFA and PV values were observed. Although elevated temperature accelerated all chemical reactions but all chemical parameters met national standards. Evaluation of sensory characteristics showed that storage temperature and packaging method had no significant effect on sensory quality of the samples. The good correlation between the PV and taste scores evaluated by panelists suggested that oxidation is one of the main reasons of off flavor in CBs. Overall, the developed compact biscuit was stable at least 12 weeks in all packaging treatments.
Key words: compressed biscuit, oxygen absorber, vacuum packaging, sensory evaluation
Aliakbar Gholamhosseinpour; Mohammad Elahi; Mohammad Javad Varidi; Fakhri Shahidi
Abstract
The rock candy is the grown sucrose crystal which has been produced in Iran and India for the first
time originally. In this process, the large sucrose crystals has been produced by cooling the
supersaturated solution. The traditional processing has not changed up to now. Recently, many efforts
were ...
Read More
The rock candy is the grown sucrose crystal which has been produced in Iran and India for the first
time originally. In this process, the large sucrose crystals has been produced by cooling the
supersaturated solution. The traditional processing has not changed up to now. Recently, many efforts
were done to optimize it. The production of rock candy evaluated under cooled crystallization process.
To increase the yield and the growth of sucrose crystals, the supersaturation and crystallization
parameters should be optimized. Due to low efficacy in this procedure, sucrose crystals with
dimensions less than 3 mm are usually produced by evaporating crystallizers. In this research,
traditional production process of rock candy is studied by doing experiments at different phases in a
traditional plant. According to the results, it takes more than 90 min to reach the suitable
supersaturation, an temperature (112°C) and extra evaporation. So the invert sugar content, reach
from 0.015 % in original sugar to 0.571 % in effluent (mother syrup). The produced rock candy has
0.553 % invert sugar. The pH of solution decreases from 7.3 to 5.2, the color increased from 70 (in
primary sugar) to 1240 ICUMSA unit in the effluent and more than 250 Iu in produced rock candy
(measurement in λ = 420nm ). The high color rate and invert sugar cause the effluent can not be used
in production process.
Key words: sucrose, rock candy, crystallization, supersaturation.
Amir Hossein Elhami Rad; Fakhri Shahidi
Abstract
Bulk tomato paste which is produced by most domestic factories in cocentrations more than 35% (35-40 degree of brix), and filled in to barels as bulk quantity under non - hermetic conditions.The microbial contamination level in this product is high since there is no any post heat treatment. for sterilization ...
Read More
Bulk tomato paste which is produced by most domestic factories in cocentrations more than 35% (35-40 degree of brix), and filled in to barels as bulk quantity under non - hermetic conditions.The microbial contamination level in this product is high since there is no any post heat treatment. for sterilization and microbial redaction Barels maybe stored at coldstore or ambient temperatures for more than 8 months. With limiting of raw material (tomato fruits) in winter ,bulk tomato paste is reconstituted and filled in cans as or commertial conservation. On the basis of the results obtained from the evaluation of fungal contaminations in bulk tomato paste in cold store ,it was determined that the main fungal flora of this product is contained different species of two genera Aspergillus and Penicillium.These moulds grow easily in temperatures near 0ْ C and influence the qualitative properties of the product. It was found that using high brix (≈38 ) in production of tomato paste and storing in 0ْc had only limiting effect on the fungal growth and could not prevent it completely.
