Showing 21 results for Kashaninejad
Volume 11, Issue 2 (Number 2 - 2009)
Abstract
Drying is an important operational step in pistachio processing. There is a decrease in moisture content of pistachio nuts from 56-57% (d.b.) to 5-6% during the drying process. Drying conditions affect the quality of dried pistachio nuts, therefore, this calls for an accurate description of the drying trend in the process. In this study finite element formulation and solution of diffusive moisture transfer equation was presented to improve the drying simulation of nut as an axisymmetric body. The Fick’s diffusive model was solved with effective moisture diffusivity of 5.24×10-10 m2 s-1 for 55C and 7.01×10-10 m2 s-1 for 70C. For experimentation, thin layers of pistachio nut, ‘Ohadi’ variety, were dried at high drying air temperatures (55 and 70°C), three replications for each treatment, along with drying air velocity and relative humidity of 0.5 m s-1 and 20%, respectively. Good agreement was observed when the output of model was compared with the experimental data. Mean Relative Deviation (MRD) calculated for the model and the experimental data for the air temperatures 55 and 70C, were found to be 6.2% and 8.1%, respectively.
Volume 14, Issue 1 (1-2012)
Abstract
In this article, the size, dimensions, volume, bulk and particle densities, empyting and filling angles of repose and friction coefficients against different surfaces were evaluated for two varieties of barley, Sahra and Valfajr, as a function of moisture content in the range of 10.12 to 42.17 (w.b.%). Most physical properties of barley varieties were significantly affected by moisture content variation. The length, width, thickness and unit mass of Sahra variety increased from 9.88 to 10.16 mm, 3.37 to 3.89 mm, 2.54 to 2.80 mm and 0.048 to 0.074 g, respectively, as the moisture content increased. The respective values for Valfajr varied from 8.37 to 8.87 mm, 3.03 to 3.21 mm, 2.21 to 2.37 mm and 0.037 to 0.043 g, respectively. In Sahra variety, sphericity, geometric mean diameter, bulk density, particle density and porosity increased from 44.59 to 47.40%; 4.38 to 4.79 mm; 568.10 to 613.68 kg m-3; 1,099.65 to 1,245.72 kg m-3 and 48.34 to 50.74%, respectively. The coefficient of static friction increased linearly against all the tested surfaces as the moisture content increased. In Valfajr variety, sphericity increased from 45.79 to 45.89%; geometric mean diameter increased from 3.82 to 4.06 mm; bulk density increased from 579.68 to 608.58 kg m-3; particle density varied from 1,410.82 to 1,230.61 kg m-3; porosity varied from 58.91 to 50.55% and the coefficient of static friction increased linearly against all the tested surfaces as the moisture content increased. The angle of repose for emptying and filling increased linearly as well.
Volume 15, Issue 5 (9-2013)
Abstract
Flow characteristics and rheological parameters of “Malas Yazdi” pomegranate (Punica granatum L.) juice were investigated using rotational viscometer at different temperatures (10, 20, 30, 40, 50, 60 and 70ºC) and concentrations (12, 22, 32, 42 and 52º Brix). The experimental data had the best fitness with Herschel-Bulkley model and the values of flow behavior index (n) varied between 0.97 and 1.45 at all temperatures and concentrations, revealing the shear thickening nature of pomegranate juice. The activation energy of flow (Ea) calculated with respect to apparent viscosity at 40 rpm increased from 9.07 to 24.05 kJ mol-1 as the juice concentration increased from 12 to 52º Brix. Power equation indicated that consistency coefficient increased non-linearly with concentration increase. A mathematical model was developed to describe the influence of temperature and soluble solids on the consistency coefficient of pomegranate juice for the studied conditions.
Volume 16, Issue 7 (Supplementary Issue - 2014)
Abstract
The aim followed in the present study was to evaluate the antioxidant activity of individual vs. combined extracts of rosemary leaves and oak fruit to detect the possible interactions in their antioxidant activity following combination and in order to find a way to use oak fruit natural antioxidants as an available massive source in Iran. Towards this end, methanolic extracts of rosemary and oak fruit were prepared and antioxidant activity of individual vs. combined extracts evaluated through 2,2-Di Phenyl-1-Picryl Hydrazyl (DPPH) free radical scavenging activity, Total AntiOxidant Capacity (TAOC), reducing power assays as well as peroxide value measurement in soybean oil. Rosemary extract revealed a significantly (P< 0.05) higher antioxidant activity than the extract of oak and than the synthetic antioxidant BHT taken as standard. In combined samples, all the three kinds of interactions were observed namely: as additive effect at 50 and 150 µg ml-1 in DPPH assay, synergistic effect at 150 and 200 µg ml-1 in total antioxidant capacity assay and antagonistic effect in the process of peroxide value measurement in soybean oil. In the peroxide value measurement assay, antioxidant activity of the combined extract was significantly (P< 0.05) higher than those of the individual extracts and that of BHT. Thus, the combined extracts of oak and rosemary can be used as natural sources’ to replace such synthetic antioxidants as BHT to either alleviate or prevent the oxidation process in vegetable oils.
Volume 16, Issue 86 (4-2019)
Abstract
Millet is one of the cereals that used in the preparation of gluten-free products for celiac patients. Physical modification methods such as heat-moisture treatments and microwave can be used to improve the performance of gluten-free flours in the baking industry. Millet seeds have limited shelf life in normal storage condition due to its relatively high fat content and high activity of lipase enzymes. In this study Heat-moisture treatments at different levels of moisture (11,15 and 20%) and two different temperatures (90 and 110°C) for 3 hours in oven and microwave treatment at different levels of moisture (11,15 and 20%) were used at different times (30,60 and 90S) with a constant power of 900 W. Then, in order to ensure the effect of the above treatments, the amount of free fatty acids of the treated flours was measured every 10 days as well as the level of lipase activity on the first day and after 30 days. In the heat-moisture treatment, the rate of inactivation of the lipase enzyme increased with simultaneous increase of moisture and temperature of the oven as well as in the microwave treatment with simultaneous increase of moisture and microwave time and the amount of free fatty acid flour during 30 days of storage was reduced. The highest rate of inactivation of lipase enzyme and the least change in the free fatty acid content of flour in heat-moisture and microwave treatments were observed in treatment with 20% moisture content and 110°C, and treatment with 20% moisture and 90S.
Volume 16, Issue 87 (5-2019)
Abstract
In recent years, infrared radiation (IR) has been considered as one of the suitable methods for drying and decontamination of different spices. However, the low penetration depth of the IR limits its use for food processing in the industry. Due to the importance of Carum carvi as a spice with medical properties, this research aimed to determine the effect of the sample’s structure (powder and seeds), water activity (0.24, 0.56 and 0.89) and the power of IR emitter (222 to 960W) on the penetration depth of the IR into Carum carvi For this propose, the heat fluxes received by copper black body that placed under samples with different thickness was measured. Afterward, the penetration depth was calculated through a mathematical model. The results indicated while aw of the sample, the IR power, and their interaction had a significant effect on the penetration depth of the IR, the structural properties of the sample had no significant effect on it. Increasing the infrared power to 601W enhanced the penetration depth in all of the samples. The highest penetration depth into the powder and the seeds of Carum carvi with aw 0.24 was achieved at the IR power of 601W, and was recorded 4.07±0.27 and 3.85±0.23mm while the samples with aw 0.89 were shown the highest penetration depth when they were irradiated by IR power of 845W) 4.12±0.18 and 4.09±0.13mm). According to the results, determining of IR penetration depth in the spice can be used to determine of their optimal thickness during the infrared food process.
Volume 16, Issue 87 (5-2019)
Abstract
Production methods of concentrated yoghurt (labane) varied from traditional methods, which are tedious, such as separation of whey by fabric bags, to complicated methods. These raise demand to establish more suitable methods such as “wheyless process” by dried milk, concentrated milk protein or concentrated whey protein. So the influence of different ingredients such as milk protein concentrate (MPC), whey protein concentrates (WPC) and konjac gum (KG) on rheological properties of labane was investigated through mixture-process design methodology and optimized these properties by firefly algorithm. The results of the combination of back extrusion and texture profile analysis (TPA) indicated that increasing KG significantly increased hardness, adhesiveness and adhesiveness force especially for samples with high amount of CWP but increasing MPC and decreasing CWP decreased cohesiveness in samples with high amount of KG. Strain sweep test of the labane indicated that all sample had gel-like structure (weak gel) at 1 Hz and 20˚C. Rheological results also showed that increasing KG significantly increased G’LVE, G” LVE, γc, τy, τf and Gf especially for samples with high amount of CWP. The optimal results of different gum percentages to achieve maximum Hardness, Cohesiveness, G΄LVE, γc, τy, tan δ LVE, Gf and minimum Adhesiveness, Adhesiveness force, G˝LVE using the firefly algorithm in PC space, it has been shown that the optimum amounts of KG and MPC were close to each other and had more variance of the data which shows the similarity of the effect of these two component on the rheological parameters.
Volume 16, Issue 87 (5-2019)
Abstract
In this research, the effects of Konjac gum (0.2-0.6%), Fat content (18-25%) and Homogenization pressure (100-200 bar) on rheological properties of low fat cream were investigated. The results of the back extrusion test indicated that increasing konjac gum, fat content and homogenization pressure, significantly increased hardness, consistency and adhesiveness. The simultaneous increasing of homogenization pressure and fat content also led to increasing adhesiveness of the samples, which showed their synergistic effect of them on the adhesiveness. The results of the steady shear test showed that the flow behavior index (n) of all samples was less than one which indicates a shear thinning behavior (pseudoplastic) of all samples. Also increasing fat content, significantly decreased the flow behavior index of the samples and increased the consistency. konjac gum and homogenization pressure had no significant effect on the flow behavior. The optimum processing conditions for producing low fat cream with the high hardness, consistency, consistency coefficient and low flow behavior index for response variables were 146/51 bar homogenization pressure،18/01% Fat content and 0.59% konjac gum.
Volume 16, Issue 88 (6-2019)
Abstract
Roasting is an important step in nuts processing and one of the ways to improve the color, flavor and unique aroma and taste, which can, in addition to positive changes, reduce the amount of nutrients in the nuts. So, It is very important to select the appropriate conditions for roasting. In this study, the effect of infrared (IR) power (400-600 W) and roasting time (4-10 min) on energy consumption, color parameters (L*, a*, b* value, ΔE, BI, SI, WI, hº), texture, moisture content and sensory properties of sunflower kernel were investigated. In addition, the regression models for the responses were obtained and the proper roasting conditions were determined using response surface methodology (RSM). Quadratic model was proposed for color change (L*، a* ،ΔE، hº، WI) and linear relation for texture, BI and moisture content and 2FI for energy consumption. Roasting at 492.5 W IR power for 9.1 min were found to be convenient or proper roasting conditions. Also, roasted kernels had acceptable quality in terms of sensory properties compared to the conventional method (hot air).
Volume 16, Issue 88 (6-2019)
Abstract
Roasting is an important step in nuts processing and one of the ways to improve the color, flavor and unique aroma and taste, which can, in addition to positive changes, reduce the amount of nutrients in the nuts. So, It is very important to select the appropriate conditions for roasting. In this study, the effect of infrared (IR) power (400-600 W) and roasting time (4-10 min) on energy consumption, color parameters (L*, a*, b* value, ΔE, BI, SI, WI, hº), texture, moisture content and sensory properties of sunflower kernel were investigated. In addition, the regression models for the responses were obtained and the proper roasting conditions were determined using response surface methodology (RSM). Quadratic model was proposed for color change (L*، a* ،ΔE، hº، WI) and linear relation for texture, BI and moisture content and 2FI for energy consumption. Roasting at 492.5 W IR power for 9.1 min were found to be convenient or proper roasting conditions. Also, roasted kernels had acceptable quality in terms of sensory properties compared to the conventional method (hot air).
Volume 16, Issue 90 (August 2019)
Abstract
Usually, raw and unmodified flours are used in the gluten-free products industry and the most common way to increase the quality of gluten-free products is to use gums. In order to increase consumer demand for non-additive products, we can improve the quality of flour and gluten-free cake by using physical treatment of cereal grains. The aim of this study was to compare the effect of xanthan gum with the effect of heat-moisture treatment on physicochemical and sensory properties of gluten-free cake from millet and rice flour (50:50). In this study, the effects of xanthan gum on two levels 0 and 0.15 %, heat-moisture treatments at three levels of moisture 10, 15 and 20% and two levels of temperature 90 and 110° C on physicochemical and sensory properties of batter and gluten-free cake from millet and rice flour (50:50) were compared. The results showed, with increasing moisture and temperature in the heat-moisture treatment, the specific weight of the batter decreased and its viscosity increased. also, the physicochemical and sensory properties of cake such as specific volume, porosity and texture of cake were significantly improved on the baking day and during maintenance compared to the control sample (p <0.05). So that the samples containing millet flour obtained at 20% moisture and 110°C did not show significant differences in the physicochemical and sensorial properties of the samples containing 0.15% xanthan gum (P<0.05). Based on the findings of this study, heat-moisture treatment can be a good alternative to gum in gluten-free cakes.
Volume 16, Issue 91 (September 2019)
Abstract
Astaxanthin is a carotenoid pigment that is used as a repellency for free radicals and active oxygenates, dietary supplements and natural colorants, as well as its therapeutic applications, and has been called natural super-antioxidants. Furthermore, astaxanthin due to its high unsaturate is susceptible to environmental factors, which can be applied encapsulation in suitable coatings and added to food products to be controlled and released under specific conditions. In this research, Astaxanthin encapsulation has been carried out in a combination of Arabic gum and whey protein concentrate. In this stage, the independent variables, the ratio of each of the walls, Arabic gum (0.5, 1, 1.5 w / w), whey protein concentrate (2, 4 and 6 w / w), as well as pH (4.5, 6.5, 8.5) were considered and their effects on turbidity, viscosity, drope size, zeta potential, and stability of nano-complex were investigated. In order to find the optimum pH of the complex formation, the adsorption rate was investigated in a wide range of pH (3-9) and pH 4.5 was determined to for a complex of whey protein concentrate –Arabic gum. Based on the results obtained from the surface response method, the treatment with number -16 (%1.5 GA, % 6 WPC in pH = 4.5) with the least stability, has the highest viscosity and maximum turbidity, the smallest drope size and the highest zeta potential was determined as the optimal sample. In the final, ratio of 6 to 1.5 between WPC and GA came up with the highest complex formation.
Volume 17, Issue 102 (August 2020)
Abstract
Chicken nugget is one of the most popular convenience food in the world. Because of high-fat content in preparation of nuggets with regular methods that causes obesity and other related diseases, other techniques like pretreatment using gum and drying came into attention. In this study, chicken nuggets coated with batter containing Balangu gum (0.25 and 0.5%) were cooked by infrared-frying method in three heat fluxes of 18.5, 21.6, 24.7 kW/m2 for 12 minutes. The effects of the process and gum concentration on moisture content, fat, total weight loss, color parameters (a*, b* and L*) and texture properties of this product were investigated. The sample containing 0.5% gum had the highest moisture content (51.80%) and by increasing the power of the infrared radiation, moisture content decreased. The lowest fat content was related to the sample with a heat flux of 24.7kW/m2 containing 0.5% Balangu gum. By decreasing gum concentration and decreasing the power of the infrared radiation, fat content of samples increased. Also, Color attribute L* which shows lightness had the lowest amount in the control sample because of higher heat during the cooking process. The hardness of chicken nugget in various treatments did not change significantly, which can be important in consumer acceptance, but cohesiveness of samples treated using infrared-gum treatment showed significant difference compared to the control sample (P<0.05).
Volume 18, Issue 112 (May 2021)
Abstract
In this study, the effect of different amounts of skim milk powder (SMP) (5 to 11.5%), milk protein concentrate (MPC) (1 to 5%) and soy flour (0 to 5%) on acidity, pH, viscosity and sensory characteristics (flavor, color and overall acceptance of concentrated yogurt were investigated using mixture design. The results of acidity and pH showed that increasing the MPC and SMP decreased the acidity and increased the pH of the sample significantly, while increasing soy flour increased the acidity and decreased the pH of the samples. The results of viscosity showed that only the linear effect of SMP and the MPC on the viscosity of samples was significant and increasing of SMP and MPC increased the viscosity of samples but soy flour had non-significant effect on the viscosity of the samples. The results of sensory score also showed that with increasing SMP and MPC, flavor, color and overall acceptance of samples increased significantly, but increasing soy flour decreased the sensory score. The results of variable importance in projection in PLS regression also showed that SMP had the highest positive significance and soy flour had the highest negative significance in terms of pH, viscosity, flavor score, color score and overall acceptance. The optimum formulation was obtained using numerical optimization algorithm in
in Design Expert software were SMP 9.8%, MPC 1.72% and soy flour 1%.
Volume 18, Issue 117 (November 2021)
Abstract
In this study, the effect of different amounts of flaxseed extract (0, 2.5, 5, 7.5, 10, 12.5 and 15%) on the physicochemical and rheological properties of kashk was investigated Then, in order to better understand the effect of flaxseed extract on the evaluated properties, Sensitivity Analysis (SA) of selected regression models was performed. The results of analysis of variance showed that the effect of flaxseed extract concentration on moisture, fat, protein, pH and solubility of kashk samples was significant so that according to the results of sensitivity analysis for each one percent increase in flaxseed extract about 4.38% moisture, 11.82% fat and 0.78% pH of the samples increased. Also, for each increase of one percent of flaxseed extract, about 7.01% of protein and 2.72% of solubility of samples were reduced. Therefore, according to the results of sensitivity analysis, fat had the highest sensitivity and pH the lowest sensitivity compared to physicochemical properties to changes in flaxseed extract. Also, the results of analysis of variance of the samples showed that the effect of flaxseed extract concentration on all parameters of Herschel model (flow behavior index, consistency coefficient and yield stress) was significant So for each one percent increase in flaxseed extract about 9% consistency coefficient and 11.82% fat and 9.03% the yield stress of the samples increased.
Volume 18, Issue 118 (December 2021)
Abstract
In this study, the drying process of pumpkin thin layers was investigated by cast tape drying (CTD) and convective hot air drying
(CHD) methods and the effect of temperature and drying kinetics of the pumpkin was determined along with the best mathematical model to fit the changes on moisture content to time ratio. At first, Pumpkin slices were prepared with 3, 5 and 7 mm thicknesses. Drying was performed at 75, 85 and 95 (°C) by CTD method and at 55, 65 and 75(°C) by CHT method in triplicate. Based on the kinetic model evaluated by Hii, Law and Cloke, the 7 mm thickness was selected as an optimum thickness in both drying methods. The optimal drying temperature ranges were 55 and 95 (°C) by CHD method and CTD method
, respectively. Five mathematical kinetic models were fitted on the experimental data using four criteria including, Determination of Coefficient (R
2), Root Mean Square Error (RMSE), Sum of Squares (SSE) and Chi-square (χ
2). Also, effective diffusion coefficient (D) and activation energy (Ea) were calculated. The results showed that
Hii, Law and Cloke’s model predicted the drying behavior during CTD. Activation energy of 37.5310588kJ/mol and 20.32657 kJ/mol was calculated for CHD and CTD methods respectively. The best mathematical model for drying a thin layer of pumpkin by CTD and CHD method was proposed Hii, Law and Cloke’s model.
Volume 19, Issue 124 (June 2022)
Abstract
Characterization of lactic acid bacteria (LAB) isolated from rarely studied fermentation substrates can lead to isolate unique microorganisms. In the present study, predominant LAB was isolated from fermented acorn using repeat of back-slopping process, and then the isolate was identified by PCR. Subsequently, probiotic properties of the isolate (including resistance to acid and bile, antibacterial, auto and co-aggregations, antibiotic susceptibility and blood hemolysis), as well as its antifungal effect were studied. Sequencing results of the PCR products led to the identification of Pediococcus acidilactis as predominant LAB isolate. The survival percentage of the isolate in continuous acid and bile treatment was equal to 72%. The inhibitory effect of the isolate on Bacillus cereus was also significantly (P<0.05) higher than the other foodborne indicator bacteria. Furthermore, crude cell free supernatant (CFS) obtained from LAB culture completely inhibit the growth of B. cereus; meanwhile, its naturalized CFS had no inhibitory effect on Salmonella enterica. LAB isolate had also proper auto and co-aggregation (with E. coli) potentials and had no hemolytic activity. Antifungal activity of the isolate against Aspergillus niger was also verified. By considering the proper probiotic and antifungal potentials of the P. acidilactis isolated from fermented acorn it is possible to use the isolate as microbial starter, adjunct, probiotic and or protective culture in fermentation industries.
Volume 19, Issue 132 ( February 2023)
Abstract
Evaluation of probiotic properties of lactic acid bacteria (LAB) isolated from fermented pseudocereals has crucial importance to prepare microbial cultures. In the present study, after molecular identification, probiotic properties of the predominant LAB isolate were investigated. Sequencing results of the PCR products led to the identification of Lactobacillus brevis SKA01 as the predominant LAB. The survival of the LAB isolate after continues treatment of acid and bile reached to 106 compared to the control sample (108 CFU/mL), and it showed the highest antibacterial effect on Staphylococcus aureus. Meanwhile, there was no significant difference (P>0.05) between inhibitory zone diameter of the S. aureus and Listeria monocytogenes in the present of the LAB isolate. LAB isolate was capable of good auto-aggregation (36.19%) and co-aggregation with S. aureus (71.24%), and it had no hemolytic activity. Furthermore, it was resistant to most of the tested antibiotics. By considering the proper probiotic potentials of the L. brevis isolated from fermented amaranth, it is possible to use the isolate as microbial starter or probiotic culture in fermentation industries.
Volume 20, Issue 144 (February 2024)
Abstract
Vegetables are perishable and cultivated seasonally. The aim of this study was to employ a combined thawing through hot air-infrared system, while investigating the effects of temperature, airflow velocity, and infrared radiation power on thawing time and the quality attributes of thawed carrots. In this research, carrot samples, having been washed and shaped using a cylindrical mold measuring 22.5 mm in diameter and 12 mm in height, were subjected to freezing at -18°C for 48 hours. Thawing parameters were air temperature (30°C and 40°C), airflow velocity (0.5 and 5 m/s), and infrared power (100 and 300 watts). The sample thawed at 25°C was control sample. Data analysis showed that reciprocal effect of increasing temperature, power of the radiation source and air flow speed had a significant effect on the thawing time, vitamin C, β-carotene, the thawing loss, and pH (P≤0.05). This system was able to significantly reduce the thawing time this time for the control sample was 47.66 minutes and for the shortest thawing time, the treatment 8 (F5P300T40) was 6.23 minutes. The lowest pH value was related to treatment 7 (F0.5P300T40) 5.81 and the highest value was related to treatment 1(F0.5P100T30) 6.15. The highest amount of β -carotene was related to treatment number 8 (F5P300T40) 48.12 mg/100g and the lowest amount was related to treatment 5 (F0.5P100T40) 14.03 mg/100g. The highest amount of vitamin C was related to treatment 4(F5P300T30) 12.36 mg/100g and the lowest amount was related to treatment 1(F0.5P100T30) 3.68 mg/100g. . In the thawing loss, the highest amount was related to treatment 1 (F0.5P100T30) 19.7% and the lowest amount was related to the control sample7.44%. . Due to the low start-up cost, shorter process time and favorable quality, hybrid defrosting is widely used in the food industry.
Volume 21, Issue 5 (9-2019)
Abstract
In the present research work, the potential probiotic properties of Lactococcus lactis KMCM3 and Lactobacillus helveticus KMCH1 isolated from raw camel milk and traditional fermented camel milk (Chal), respectively, were studied. The probiotic properties of isolates that were investigated included the hemolysis, antibiotic resistance, antibacterial features, resistance to low pH and bile salts, survival under simulated GastroIntestinal Tract (GIT) conditions, adhesion ability to hydrocarbon, and their auto-aggregation and co-aggregation rates. None of isolates exhibited hemolytic activity. They were susceptible against tetracycline, penicillin, ampicillin, chloramphenicol, erythromycin and vancomycin. Lac. lactis KMCM3 and L. helveticus KMCH1 retained their viability at pH 3.0 (8.68 and 8.6 log cfu mL-1, respectively), 0.3% w/v bile salts (8.23 and 8.58 log cfu mL-1, respectively) and under simulated GIT conditions (8.31 and 8.46 log cfu mL-1, respectively). Both of these isolates inhibited the growth of E. coli, S. aureus, L. monocytogenes, B. cereus and S. enterica subsp. enterica serovar Typhimurium with MIC values of 6.25 to 25 mg mL-1. In addition, They exhibited an ability to adhere to hydrocarbon (xylene), and possessed a high auto-aggregation and co-aggregation rate (more than 40%).
