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  Effect of two storage temperatures -14±2˚c and -28±2˚c was investigated on distribution and redistribution of Fe, Cu, Zn, Mg, Mn, Hg, Pb and Cd metals in tissue and viscera of green back mullet. Statical results showed that average amount of Fe metal in tissue of mature and immature fish stored at -14˚c (respectively 77.1 ppm and 166.6 ppm ) was more than both fresh mature and immature fish (28.5 ppm and 88.1 ppm) and fish stored at -28˚c ( 26 ppm and 109.1ppm). Amount of Zn metal in the viscera of mature fish stored at -28˚c (56.8 ppm) was more than fresh fish (43.5 ppm) and fish stored at -14˚c (43.5 ppm). Likewise amount of Pb metal in the viscera of immature fish (59.9 ppm) and fish stored at -14˚c (58.3 ppm) was less than immature fish stored at -28˚c (110.2 ppm). Considering that the amount of other metal did not show significant changes during frozen storage, it seems that -28˚c temperatures provides better quality from the view point of distribution and redistribution of heavy metals, and fish tissues stored at this temperature have more food immunity and health for consumers.    

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  The flat breads (Sangak, Barbari) have got great importances Iranian diet. The quality of these breads is very important from consumer point of view and the inferior quality would cause the bread loss in the country. The aim of this research was to study the effect of the freezing, freeze storage and freeze thaw on the quality of two flat breads. For this Sangak and Barbari were baked and packed on polyethylene bags and stored at -18˚C in household freezer. The breads were taken out after periods of one, two, and three weeks from the freezer and thawed at room temperature and heat condition (80˚C). The textural properties of the frozen breads were determined in DSC and TPA apartuses, and the sensory tests were done with scoring method by trained panels. The results of the DSC study showed that in the periods of 1, 2 and 3 weeks the retrogradation stopped on these breads and the amount of starch retrogradation in thawed breads (at room temperature and heat condition) did not show significant differences (P<0.001). The results from the TPA showed that the amount of force needed to make slices of the breads were significantly different (P<0.001). The results of sensory test in the case of thawed bread under heat condition had acceptable quality. From the result of this research it can conclude that the freezing can be used for preservation of these breads and thawing of them should be done under heat condition.

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  According to increasing trend of the consumption of ready to use leafy vegetables, mainly impact of freezing on sensory attributes of the vegetables and necessity of determination of the best conditions for frozen storage of leafy vegetables, this research carried out for determination of the best frozen storage time and temperature of Allium ampeloprasum, Lepidium sativum and Stureia hortensis mixtures. This study was done at first for storage of ready to use and comminuted leafy vegetables entitled Ghormeh Sabzi mixture in -9, -12 and -18°C as well as 120, 150 and 180 days by explorer method. At second for frying of vegetables of Ghormeh Sabzi and comparison of sensory attributes of freezed vegetables at each month by experimental method. Sensory attributes all treatments containing color, taste and acceptability were evaluated and compared statistically. The results of freezing temperature in 3 times indicate that color in -18°C is the first rank (P≤0.05). Flavour has the first rank in -18°C in 120 and 150 days but flavour in 180 days in -12°C is the first rank without significant difference with -9°C and -18°C. Furthermore, acceptability in -18°C in 3 times is the first rank. The results of freezing time during 3 temperatures indicate that color, flavour and acceptability are not significantly different. The research results indicate that sensory attributes of the vegetables during 180 days frozen storage is affected by freezing temperature mainly rather than freezing time.  

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Effect of gamma irradiation on total volatile base nitrogen (TVB-N) and sensory evaluations of Indian white shrimp (P. indicus) held frozen (-18˚C), for 9 months and every 1.5 months, was studied. TVB-N values increased gradually during the storage period rn and decreased with increasing irradiation dose that reached 20.64, 27.45, 34.14, 35.45 mg N/100g flesh, respectively for irradiated and control samples. Also with organoleptic evaluation indicated that, shelf-life of 5, 2.5 KGy samples increased up to 3 months and 1 KGy samples increased up to 1.5 months compared to control samples. rn  

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Bread has great importance in nutritional needs in Iran. The main kind of the breads are flat breads, they have got short shelf life, and there high percent of wastage in the case of this types of   bread. Since the way which these breads preserves is important and one of the preservation method is freezing .the aim of this work was the study of the effect of the freezing and freeze storage on freeze thaw and the qualitative characteristics of Lavash bread. The raw materials were prepared, chemical specifications of  the frozen Lavash (different panel) after thawing, studied. The Level of retrogradation with the DSC and the textural properties of the breads determined with the Instron. The sensory properties evaluated by the ranking method and was done by trained panels. The statistical parameters were measured by descriptive statistics One-way ANOVA and Tukey's test. The ranking method use for analysis of sensory scores. Results showed that within period of freeze storage, the retrogradation stops, and the force needed to make the slices of  the bread was related to the period of freeze storage and there were significant (p<0.001). The amount of the retrogradation for the breads thawed by heat. The amount of the force needed for the slicing of the breads had significant differences and from sensory point of view the breads which thawed by the heat has higher score than the breads thawed at R.T. The results of this research indicated that, the Lavash bread was not affected that much by freezing, processes quality, and when it is thawed by heat it showed better quality and high acceptance by consumer, as a result, freezing method can use for Lavash bread storage and heat can be use for the thawing of bread.

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The aim of this study was to evaluate the quality of thawed silver carp in refrigerator. Silver carps were kept in -18°c for 3 months pre and post rigor mortis. After thawing they were kept in refrigerator for 12 days, meanwhile quality assessment of fishes was performed in days of 0, 3, 6, 9 and 12 by measuring chemical (FFA, TBA, TVB-N, Expressible moisture, pH and moisture contents), microbial (Total viable counts) and sensory factors (Raw and cooked fish). Freezing post rigor mortis and increasing storage time led to increase of FFA, TBA, TVN, Expressible moisture and pH contents, but decrease of moisture content. Although TVB-N elevated by increasing refrigerated storage, but its content for post-rigor frozen fishes was more than pre-rigor frozen fishes. Also, Total viable counts showed higher bacterial numbers in pos-rigor frozen fishes (p<0.05). Although silver carps were edible during 12 days, but sensory analyses of raw and cooked fishes indicated unsuitable quality of silver carps after 6 and 3 days in pre- and post-rigor frozen samples, respectively. Therefore, based on obtained results, freezing of silver carps before the onset of rigor resulted in increase of their shelf life during refrigerated storage

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  Introduction: Pure water freezes at zero degrees of Celsius. By dissolving any material in the water its freezing point will be decreased, similar to water, some ingredients of milk such as lactose, ion Chlorides decreases the freezing point. The main factors affecting the freezing point of milk are: added water during milking and gathering, high microbial load, mastitis, adulteration including the addition of Ionizable materials for example salt and etc.  Objectives: To determine the average bovine milk freezing point, the percentage of none-fat-solid (SNF) and  elemental mineral content(EMC) at the same time. Materials and methods: This is a descriptive analytical study which was done in Kermanshah province by using 100 milk samples from complete milk of healthy cow in definite time point by simple random sampling. The samples transported to laboratory in less than 3 hours , freezing point of each sample has determinated by calibrated cryoscope , the percentage of SNF and EMC   has determinate  by calibrated  Milk  analyzer . Results: beyond standard conditions of milking, collection and immediate testing, results showed that mean freezing point of milk was -0.519,  mean SNF was 8.23 and  mean mineral percentage was 0.74.. Conclusion: Since the Institute of Standards and Industrial Research of Iran in the 4th revision of the pasteurized milk standard (Standard 93) has limited the percentage of SNF of milk to  8 and freezing point  to -0/507 to -0/545, which are not at the same line. Moreover, other factors such as EMC have underestimated, we suggest that the freezing point of milk without measuring EMC 

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In recent years, following the mechanization of life, people tend to have products with higher quality and longer shelf life. Following this demand, studies have been introduced different technologies to the food industry; the part baked and frozen bread has been more attention. Although freezing, frozen storage and thawing have detrimental effect on bread properties. Use a variety breads improvement such as emulsifiers, oxidants and hydrocolloids can be used to reduce this impact without any negative effect. The aim of this study produce semi volume Barbari bread as part baked and frozen storage, in order to increase their shelf life and adding guar gum and lipase to formulation for improve quality, rheological and sensory characteristics in cycle freezing, storage and thawing. Bread prepared as part baked, freezing in -18ċ and storage for 15 day, after this time samples were thawing and full baked.  Then volume, porosity, texture, index image and sensory properties were measured. For Data Analysis used Statistica software and Duncan test, for mean comparisons. The result showed guar gum in 0.4 concentrations can be improvement volume, porosity, texture, index image and sensory properties, lipase at 0.05 level influenced on volume, porosity, texture in sensory properties and index image.  

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Objective: Evaluation of the effects of different doses of antioxidant Taurine on oxidative stress and human sperm parameters following cryopreservation. Materials and Methods: The semen of 20 fertile men were divided to 5 aliquot, one part considered as a fresh after analysis of standard semen parameters (Motility, Abnormal Morphology, Viability) and Protamine deficiency, DNA damage and measurement of ROS and RNS. The other part was loaded on to a 80% and 40% Allgrad gradient and centrifuged. The pellet was washed and divided into 4 separate fractions for control (non-frozen) and cryopreservation groups in absence or presence of 0.25 and 50 mM Taurine. The frozen specimen were thawed and then examined. Sperm Motility evaluated using a CASA software. The Viability of spermatozoa was assessed by the Trypan-Blue stain method. Levels of ROS determined by spectroflorometry assay using DCFH-DA. DNA fragmentation examined by SCD test and Protamine deficiency examined by CMA3+ staining. At the end results were analyzed using ANOVA test. Result: Cryopreservation procedure increased the amount of ROS and adding 25 mM of Taurine improved post-thaw motility, progressive motility and sperm protamine deficiency. However, different doses of Taurine (25 and 50 mM) had no significant effects in total abnormalities, viability, DNA fragmentation and ROS reduction. Conclusion: Antioxidant Taurine has no significant effects on ROS production following human sperm cryopreservation. But with dose of 25mM could improve the quality of spermatozoa due to the assessment of motility and protamine deficiency.

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The purpose of this study was to investigate the effect of different methods of preparation of raw rainbow trout (Oncorhynchus mykis) (full, empty stomach, fillets and fillets of butterflies) on quality and shelf life was over 4 months of storage in home freezers. To this end, rainbow trout  transferred to the laboratory and washed, were prepared by the method described and qualitative assessment of fish at the end of each month by measurement of chemical parameters (free fatty acids, thiobarbituric acid, protein, fat, moisture, ash, under pressure moisture, pH, heme iron content) and sensory (flavour, odor, texture, color) were performed. With increasing storage time heme iron content reduced, so that at the end of storage heme iron content was more in treatment of whole fish. Also under pressure moisture, TBA nad FFA increased in different treatments and in the fourth month of storage, the rate of these variables were lower in treatments of whole fish. Sensory analysis results indicate utility of all treatments decreased with increasing storage time but the rate of decline was less than in whole fish. According to the results, as can be fish kept in perfect shape than in other forms it is recommended.

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Simultaneous Heat and Water Model (SHAW) is based on the assimilation rate of melting and/or freezing of the accumulated snow as well as melting of ice in soil. The main objective of this study was to evaluate applicability of SHAW Model in determining maximum depth of frost penetration in soils in some typical climates of Iran. To this end, the daily data of air temperature, soil temperatures at different depths, duration of bright sunshine, and air humidity were collected for the period of 1992-2003 for four meteorological stations of Iran including Shahr-e- Kord, Urumia, Sanandaj, and Yazd. Then, the maximum soil frost penetration depth (SFPD) for each year in the above mentioned stations was determined based on both the measured temperatures at different layers of soil and the calculated values using SHAW Model. Results of the analyses indicated that there was a significant linear relationship between the observed and the calculated values of maximum SFPD. The obtained coefficients of linear correlation between the observed and the calculated values for meteorological stations of Shahr-e-Kord, Urumia, Sanandaj and Yazd were 0.90, 0.77, 0.84 and 0.94, respectively, all being significant at one percent level. According to the results, it was concluded that, with the yearly records of weather parameters and soil conditions, a reliable estimate of the maximum annual depth of soil frost penetration can be made in similar regions of Iran by application of SHAW Model.

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Application of combined technology can reduce the disadvantages of each other as compare to their individual process. Osmotic process along with hot air drying and freezing were applied on red beet pieces in this investigation. red beet divided to slices as well as cubes pieces before treatment with citric and ascorbic acids in two levels of 0.1 and 0.3 percent. red beet slices were semi dried in cabinet drier for period of 75 minutes and cubes for 115 minutes and then were placed into polyethylene bags for prior to freezing process in freezer with -25◦C. Different physicochemical characteristics such as acidity, water activity, image processing and texture were evaluated after 2 hour and 30 days. Statistical analysis of data with completely randomized design and SPSS software version 20 during one month preservation showed that cubes pieces of red beet in 0.3 percent of acid solution along with osmotic dehydration has the best and comparable texture, color and quality characteristics as compared to the fresh red beet.     

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Effects of Lepidium perfoliatum seed gum (LPSG) concentration (0, 0.3 and 0.6 wt%) and different processing treatments (freezing, pasteurization and sterilization) on physical and stability of oil-in- water emulsion prepared by whey protein (6 wt%) was investigated. For this purpose, particle size distribution, creaming index, microscopic characteristics, viscosity and flow behavior of emulsions were studied. Results showed that thermal processing increased the particle size of dispersed phase. Results also showed that the damage of membrane surface at high temperature such as sterilization was higher than other temperatures. At low Lepidium perfoliatum seed gum concentration, the emulsions were somewhat more resistant to thermal processes. However, at higher gum concentrations (0.3 and 0.6%), thermal processing did not have a negative effect on the emulsion stability. The viscosity and consistency coefficients also increased with increasing gum concentration. Shear thinning behavior for emulsions at all thermal treatments were also observed. Therefore, adding LPSG to the emulsion could increase its stability to the thermal processing.

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Maintaining the nutritional quality and preserving pomegranate seeds is a major challange due to the fast degradation of the texture, color and overall quality of pomegranate seeds. In order to investigate the freezing of coated pomegranate seeds with chitosan and determine its quality during freezing storage, an experiment was conducted, in a factorial arrangement in a completely randomized design with three replications. Factors were: chitosan at three levels (0, 1 and 2%), freezing temperature at two levels (-14 ° -24 ° C) and time at 5 different storage times (14 days, 30 days, 60 days, 90 days, and 120 days). The highest tissue firmness was observed for 14 days of storage under both chitosan concentrations. Interaction of different levels of chitosan coating and time had an increasing effect on the color component changes, so that the most color changes in the brightness (L*), redness (a*), and yellowness (b*) was related to the use of chitosan coating 2%, were maintained at 60 days. The highest total soluble solids were related to 1% chitosan under 4 months of storage at -14°C. Maximum total acidity (1.36 mg / L) was also attributed to coated pomegranate seeds during 120 days of storage under both freezing temperatures of -14°C and -24°C. The results of mean compares showed that the total phenol stability under freezing temperature was higher at -14°C and after 120 days of storage, more phenol content was observed in the seeds in -24^° C. The overall results indicated a positive effect of chitosan on maintaining the quality of pomegranate seeds during freezing, and the freezing temperature of -24^° C with decreasing color changes during storage, played an important role in reducing metabolic activity and reducing anthocyanin degradation and was effective in maintaining fruit quality.
 

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Mulberry is a fruit that has a considerable acceptance among consumers. The short harvest season and low persistence of this fruit have led to the use of methods such as freezing that have the least effect on phenolic compounds and antioxidant properties and sensory properties of the mulberry. One of the problems of sensory evaluation is the non-parametric results of the answers and the low accuracy of their analysis. Today, methods such as fuzzy logic allow inaccurate parameters to be analyzed by mathematical methods. In the present study, mulberry was stored in a freezer at -18 °C for six months and removed from the freezer at 0, 72 h, one month, two months and six months. After juice making, the sensory evaluation was performed using five-point hedonic method and the data were analyzed using fuzzy logic methodology, while attributes were color, aroma, taste, and feel mouth. Also, pH, acidity, antioxidant activity and total phenol content were evaluated. Sensory evaluation of the samples showed that the freezing of the mulberry increased the overall suitability of the samples in 72 hours and did not show a decrease in sensory properties during 6 months. Panelists assessed the importance of sensory attributes including taste, mouthfeel, fragrance, and color, as well. Although, sensory evaluation did not decrease the sensory of juice, significant decrease of pH (19.83%), increase in acidity (0.31%) and a decrease in antioxidant activity (about 14%) and phenolic compounds (about 21%) during freezing was observed. According to the obtained results, freezing can be suggested as an acceptable method for long storage of mulberry fruit.

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Heavy metals are elements that exhibit metallic properties such as ductility, malleability, conductivity, cation stability, and ligand specificity. They are characterized by relatively high density and high relative atomic weight with an atomic number greater than 20. Clay and other soils may become contaminated by the accumulation of heavy metals and metalloids through emissions from the rapidly expanding industrial areas, mine tailings, disposal of high metal wastes, leaded gasoline and paints, land application of fertilizers, animal manures, sewage sludge, pesticides, wastewater irrigation, coal combustion residues, spillage of petrochemicals, and atmospheric deposition. Heavy metal contaminants in addition to geotechnical problems creation and change in the soil strength parameters especially in clay soils, can cause environmental and human health risks due to penetrate through the groundwater. Most commonly heavy metal found at contaminated sites are lead (Pb), chromium (Cr), arsenic (As), zinc (Zn), cadmium (Cd), copper (Cu), mercury (Hg), and nickel (Ni). Also, freezing and thawing cycles have a significant effects on the behavior of stabilized clay soils specially on the heavy metal contaminated clay soils stabilized by cement od other additives. So, by population increasing, advancement of technology and consequently increase in heavy metals emissions, as well as being a quarter of the earth surface in the cold regions and the necessity of building design and construction on these soils, it seems necessary to study the impact of the freezing and thawing cycles on the stabilized clay soils. Different additives such as cement, lime, gypsum, fly ash and other additives were used for stabilization and solidification of heavy metal and oily contaminated soils, the cement is more practical among the stabilizer additives, because of its compatibility with pollutants and high efficiency, low cost and easy access. In this research used cement for stabilization of the lead heavy metal contaminated soil exposed to freezing and thawing cycles. According to the importance of the soil settlement in the clay soils, one dimensional consolidation test was conducted on the experimental samples. Also, due to extensive use of bentonite clay soil in contaminated sites, bentonite clay sample was used for experimental studies. The results of this research indicate that in most cases the critical cycle is a cycle 7. Also, The soil strength parameters such as over-consolidation stress increased about 2 to 8 times in different conditions by cement stabilization. Also, stabilization of heavy metal contaminated by cement clay soils that exposed to freezing and thawing cycles reduce the Cc and Cs coefficients of bentonite clay samples about 50 to 80 percent depending on number of freezing and thawing cycles and heavy metal concentration in bentonite clay sample and also causing preconsolidation in soft clay soils or normally consolidated soils throug the pozzolanic reactions of soil and cement at a low time. Furthermore, the optimum content of cement in contaminated and uncontaminated samples in different freezing and thawing cycles is variable, but in most cases is about 5% to 10% depending on number of freezing and thawing cycles and heavy metal concentration in bentonite clay sample. In continence, stabilization efficacy and the formation of hydrated compounds of cement and clay soil was investigated by using pH chemical test.

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Various solutions have been suggested to overcome the issue when cooling peak hours and electric energy consumption coincide. One of the solutions is to store the cooling load at off-peak hours. One of the most conventional types of storage systems is the ice-on-coil storage system. The low heat transfer rate in this system is one of the challenges. Since the conduction heat transfer coefficient of ice is low, by starting the ice formation, the heat transfer between the refrigerant inside the coil and the reservoir’s water will reduce. One idea to increase the heat transfer rate is to postpone the starting time of the freezing process to keep active the natural convection mechanism. In the present study, mechanical vibration has been used to linger freezing initiation in ice-on-coil energy storage system. The effect of longitudinal and lateral positioning of the probe, on the amount of temperature and initiation time of freezing as well as the amount and structure of formed ice has been investigated. The results revealed that placing the vibrator at the middle of coil over its two ends leads to further increase in the amount of formed ice. It is found that applying mechanical vibration can postpone the initiation time of the freezing process and decrease the subcooling temperature. Moreover, it is shown that the amount of ice formation is a function of subcooling temperature and initiation time of freezing. Finally, the energy consumption of the vibrator and the energy consumption reduction in peak-hour are calculated.

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Self-compacting concrete as a type of concrete that has no need to vibration can use for complicated frameworks and in conditions that compaction is hard. So this concrete is an excellent choice for repair and retrofitting of many kinds of concrete structures such as marine structures, bridges and so on. These concrete structures may be under aggressive environmental conditions and harmful agents. One of the most important damages of concrete structures is because of freezing and thawing cycles especially in exposed ones, like bridge’s decks. So, study of effect of different parameters on quality of self-compacting repair layer, its bonding to substrate and its durability under chemical and physical attacks is very important. In this study, effect of paste volume, water to cementitious materials and polypropylene fiber dosages in mix design on rheological, hardened properties and bonding of repair fiber-reinforced self-compacting concrete (FRSCC) to concrete substrate and its durability for freezing and thawing cycles has been assessed. Bonding between FRSCC as a repair layer and concrete substrate had been evaluate using pull-off test. The tests that failed exactly from the bond surface considered as a successful ones, and all tests that failure had been occurred in repair layer or concrete substrate is eliminated from the results. Freezing and thawing test was conducted according to ASTM C666. Both freezing and thawing processes were made in water. To assessment of bonding of FRSCC as a repair layer to concrete substrate, we made 15 cm cubes of substrate layer with compressive strength more than 50 MPa to ensure that the failure doesn’t occur in this layer while pull-off test. After six months (to have concrete substrate without shrinkage),we saw the cubes divided them to 3 pieces. With analyzing of effects of fiber dosages on rheological properties of the mix designs, we found that an increase in fiber percentage that leads to smaller diameter in slump flow test, higher flow time in T50 test, higher time in V-Funnel test, and lower ratio in L-Box test. Also, while compressive strength had no significant changes, tensile strength and modulus of elasticity experienced a big increase through adding polypropylene fibers. Shrinkage of repair layer had a great decrease after adding polypropylene fibers. The optimum dosage of polypropylene fibers for hardened properties of the mix designs was found 0.1% by volume. We can see that because of the positive effect of fibers on decreasing of shrinkage and increasing of tensile strength of repair layers, bonding between the repair layer and concrete substrate increased greatly especially by adding 0.1% polypropylene fibers (by volume). Also, increase of paste volume and water to cementitious materials (summation of cement and micro silica) had negative effect on bonding of repair layer to substrate. That is because of increase of shrinkage of repair layer. Although, adding polypropylene fibers improved bonding of repair layer and substrate in freezing and thawing cycles, we see smaller results for bonding. We defined debonding index (DI) that presents the rate of debonding during freezing and thawing cycles. Higher DI, higher rate of debonding. As we can see, for mixes that containing polypropylene fibers, DI is bigger in comparison with the ones without them.

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Hamburgers are one of the most widely consumed meat products in the world. The shelf life of this product is rather short, therefore the freezing process is commonly used to reduce water activity and prevent the growth of microorganisms. Accurate temperature prediction during freezing is important in designing optimum cooling procedures and to avoid quality deterioration. Models for predicting freezing times range from relatively simple analytical equations to the more complicated numerical methods which require a lot of computing time and a sophisticated computer. In this research, thermal properties of hamburger, including ice fraction, thermal conductivity and specific heat were determined mathematically and then the freezing process of hamburger patty was investigated by two different numerical models (finite difference& finite element). The results were compared with experimental data and it was found that although both two models could reasonably forecast the temperature of hamburger patties during freezing, the finite element model demonstrated better goodness of fit than finite difference model. This study shows that the use of CFD packages such as COMSOL software can be considered as a suitable option for the estimation of freezing time of meat products.