Showing 18 results for Sarabi
Volume 2, Issue 3 (Autumn 2019)
Abstract
Molecular imprinting is a novel technique for preparing specific absorbents with selective sites for binding to the target molecule. Molecularly imprinted polymers, because of their high selectivity and stability, low cost and easy methods of preparation, have been widely employed in separation procedures. In this study, we evaluated the synthesized electrospun imprinted membrane (MIM) as a specific sorbent for herbicide mecoprop (MCPP). The films were prepared using methacrylic acid (MAA) as functional monomer and polyethylene terephthalate (PET) as a main part of polymeric solution and in the presence of dichloromethane (DCM) and Trifluoroacetic acid (TFA) as the solvents. The template was extracted through washing, results in the free specific memory sites within the films. Then, the synthesized electrospun imprinted membrane (MIM) was evaluated as a specific sorbent for herbicide mecoprop (MCPP). The results showed that the solution with 20% w/v of PET was the optimal solution for electrospinning process and at all different MCPP/MAA molar ratios (1:2, 1:4. 1:6 and 1:8), MIM had higher removal ability for template molecule (p<0.05) compared to NIM. The template/monomer ratio of 1:4 had the best binding amount. We also investigated the capability of MIM to be used as sorbent for pesticide 2,4-D, that is, the analogue of the main template molecule and diazinon, that is, the pesticide with different structure to the template. In addition, we used synthesized MIM and NIM films to extract MCPP analyte from environmental aqueous samples (bottled water and groundwater) and the results indicated successful performance of MIM compared to NIN.
Volume 10, Issue 4 (Fall 2022)
Abstract
Aim: This study investigated the variation in plant diversity, floristic quality indices, and the forest integrity of various broadleaf forest types.
Materials & Methods: In this study, we used 288 plots of 1m2 in the middle Zagros forest to investigate the role of three forest types including Quercus infectoria, Quercus brantii, and Pyrus glabra on forest diversity indices and floristic quality
Findings: results revealed significant differences in Shannon wiener, Margalef, and Menhinic indices, as well as some soil properties, between forest types, but no significant differences in evenness and Simpson indices. Diversity indices mean coefficient of conservatism and floristic quality index (FQI) were significantly greater in the protected forest dominated by Quercus infectoria than in other protected forests.
Conclusion: This study demonstrates that tree species and certain topographical and edaphic factors have distinct effects on the distribution of understory plants, plant diversity, and floristic quality in different forest types. The results of this research, while confirming the use of plant diversity indices, also introduce the conservatism coefficient and species fidelity as additional tools in evaluating forest integrity, because by using them, more and better information can be obtained about the conditions of the forest.
Volume 12, Issue 5 (Supplementary Issue - 2010)
Abstract
Probiotic products highly affect the health of consumers by reducing the risk of heart
attacks and improving the desirable microflora in the intestinal tract. In this study the
effect of yogurt (500g/d for 3 wk) enriched with either Bifidobacterium bifidum or
Lactobacillus acidophilus on the level of cholesterol, Low Density Lipoprotein (LDL) and
High Density Lipoprotein (HDL) of serum and as well on the intestinal microflora were
investigated in 24 healthy volunteers. Statistical analysis indicated that lower levels of
cholesterol and HDL were found after consumption of either one of bio-yogurts as
compared to the control states (P<0.05), whereas changes of LDL were not significant.
Also, in comparison with control periods the results of microbial counts indicated that the
number of fecal coliforms excreted during the consumption of either one of the yogurt
types were not noticeable, while the number of Bifidobacterium bifidum and Lactobacillus
acidophilus increased significantly (P<0.05).
Volume 13, Issue 61 (3-2016)
Abstract
Volume 16, Issue 90 (August 2019)
Abstract
This study was carried out to determine the sources of microbial contamination in Doogh production line during a year in a dairy factory. Samples were taken from different control points from the beginning to the end of the production line including raw milk, pasteurized milk, water, culture, Doogh yoghurt, pasteurized Doogh, packed Doogh, filler and filling air duct, storage hall for pasteurized Doogh, and filling and storage rooms. The microbial analysis of the samples was performed to determine the total count of microorganisms, mold and yeast, coliforms, E. coli, Psychrophilic and thermophilic microorganisms, lactic acid bacteria and coagulase positive staphylococci in accordance with national standards of Iran. The results showed that Doogh health quality depends on the quality of raw milk, the adequacy of heat treatment, microbial quality of the ingredients and packaging materials, doing suitable CIP and disinfectantion of processing surfaces and factory environment. The results indicate that the assessment of critical control points and the organization of automatic control systems are necessary in order to eliminate or minimize the risk of microbial contaminats.
Volume 17, Issue 101 (july 2020)
Abstract
Due to the growing demand for biocompatible natural ingredients, the use of hydrocolloids in the food industry is on the rise. Restructured foods are one of the most important aspects of the food industry, involving a complex mix of ingredients, as well as texturing and structuring processes. Achieving an optimal formula for gel formation with appropriate elastic texture can allow for the industrial application in various stuffed products such as olives and related products. Therefore, in this study, gelatin as a gelling agent at 3, 4 and 5 wt% and guar gum as a thickening agent at 0.5 and 1.5 wt% in 1 wt% citric or lactic acid were selected as restructured Ricotta cheese formulation and evaluated of textural properties and shelf-life. Tests included textural characteristics, gel stability, and shelf-life of the restructured cheese. Therefore, the appropriate formula of restructured cheese with appropriate textural properties was selected and evaluated for microbial properties. Due to the importance of sensorial properties of this restructured product, its sensory characteristics were also investigated. Process conditions during storage of samples were also investigated in citric and lactic acid. Finally, the formula containing 4% gelatin and 0.5% guar gum in the solution containing 1% citric acid was selected as the desired sample.
Volume 17, Issue 108 (February 2021)
Abstract
In this research extraction of Salvia leriifolia leaf was carried out using two extraction methods including traditional solvent extraction (with different solvent ratio of water /ethanol 50:50, 60:40 and 70:30 at temperature 70, 80 and 90 ºC and time duration of 30, 75 and 120 min), and superheated solvent extraction (at temperature 130, 145 and 160 ºC, time duration of 10, 20 and 30 minutes and solvent ratio of water/ethanol 60:40, 80:20 and 100:0) and the antimicrobial activity of extracts against some of food microorganisms using minimum inhibition concentration and minimum bactericidal concentration methods were measured. In both extraction methods, the MIC of most microorganisms was 0.5 mg/ml, while the MBC, depending on the microorganism, was between 5 and 500 mg/ ml. In the conventional solvent extraction procedure, the treatment was carried out at a temperature of 80 ° C, 75 minutes, and equal ratio of two solvents, and in superheated solvent extraction method, treatment including temperature of 160 ° C, time of 20 minutes, and water/ Ethanol ratio of 80 to 20 showed the most antimicrobial activity. Based on the results, it can be stated that the type of plant extraction method has a significant effect on inhibiting or preventing the growth of food borne or spoilage microorganisms, and if any of the plant extraction technique are optimized, they can be better used to increase the shelf life of food.
Khalili Khalili, , Atena Ezatian Sarabi,
Volume 18, Issue 1 (3-2018)
Abstract
The present study investigates the thermal response of individuals whose forearms were subjected to severe cold stimulation and how it is influenced by the personal and physiological characteristics. So, the hands’ transient thermal responses of 89 individuals (male) was observed by thermography imaging technique. Then, statistical analysis was employed to establish an experimental relationships to estimate the thermal response time of the subjects with different individual and physiological conditions. The results showed that among the 9 individual and physiological parameters (age, vascular fat, muscle percentage, fat percentage, body mass index, systolic blood pressure, diastolic blood pressure, heart rate and fasting time), only four independent parameters including internal fat, body mass index, systolic blood pressure and fasting time are significant related to the response time. Also, using multivariate linear regression, a relationship was developed to estimate the thermal response time of the subjects against cold stimulation. This relationship indicates that the response time of the obese can be up to 20% higher than that of the lean subjects. In addition, the results shows that for each one hour after the last meal, the thermal response of the body is slower about 1%.
Volume 18, Issue 5 (9-2016)
Abstract
Aflatoxins are potent carcinogenic and immunosuppressive agents. Acute exposure to high level of aflatoxins leads to aflatoxicosis, which cause rapid death due to liver failure. Immune modulating effects of probiotic bacteria have good prospects to detoxification of natural foods. This study was aimed to investigate the ability of Lactobacillus acidophilus strainLA-5 in the presence and absence of yoghurt starter culture for removing Aflatoxin M1 (AFM1) in comparison with yoghurt starter cultures (108 CFU ml-1). AFM1 detoxification was evaluated for 21 days of yoghurt storage at 4°C at different concentrations of Aflatoxin (0.1, 0.5 and 0.75 µg L-1). The amounts of unbound AFM1 were determined using competitive Enzyme-Linked Immunosorbent Assay (ELISA). L. acidophilus combined with yoghurt starter culture and alone could significantly (P≤ 0.05) remove AFM1 compared to control group. The results indicated that increasing initial AFM1 concentration in the yoghurt samples and storage time affected the capacity of AFM1 binding.
Volume 18, Issue 115 (September 2021)
Abstract
The high levels of tomato production as well as its perishability, make the development of research on processing and improving the quality of existing products more evident. The aim of this study was to assess the effect of whole tomato heating treatment by steam on the physicochemical and structural properties of produced tomamto paste with different degree of Brix (°Br). The fresh tomatoes was washed with water followed by exposing to steam and the tomamto paste with different °Br (18-26) produced through hot breaking approach. The results showed that the color indexes, precentage of precipitation weight ratio, acidity, viscosity, consistency and microstructure of final products were significantly influenced by steam preheating. The color indexes of *a and b* and precentage of precipitation weight ratio were negatively affected by steam preheating. The reason behind these observation is increasing the efficiency of heating process in hot breaking stage reulted in lycopene destruction. On the other hand, the viscosity and consistency of tomato paste were meaningfully increased. The images of scanning electron microscopy revealed that the steam preheating brought about solube pectin to migrate from cell wall, forming an amorph structure. Considering the acceptble range of color indexes as well as profound improvment in rheological characteristics of produced tomamto paste, in can be concluded that applying preheating treatment by steam would be of efficeint procedure in tomato paste production.
Volume 18, Issue 117 (November 2021)
Abstract
Spoilage of dairy products can be caused by a variety of microorganisms, including bacteria, yeasts and molds. due to production of mycotoxins by some molds in dairy products, it is important to identification of exact causes mold in order to adopt an appropriate method to prevent such contamination; Therefore, in the present study, 30 samples of contaminated Doogh with signs of spoilage such as swelling, bad smell and bitter taste were collected from a dairy factory during one year. According to the results, molds were observed in only two samples. After purification, 4 isolates were identified based on macroscopic observations, microscopic characteristics and PCR technique. Three isolates were Aspergillus flavus, and one isolate was identified as Penicillium chrysogenum. Due to the ability of the identified species to produce toxins, monitoring the critical points of the Doogh production line in order to process control and prevent secondary contamination in order to achieve a healthy product will be very important.
Volume 18, Issue 120 (February 2021)
Abstract
Gamma aminobutyric acid (GABA) is a non-protein bioactive compound that can be effective in controlling many diseases such as Alzheimerchrs, hypertension, stress, etc. The main stimulus for the production of GABA is the enzyme glutamic acid decarboxylase (GAD), which is highly active in lactic acid bacteria. Also, the presence of monosodium glutamate (MSG) can act as a substrate for this enzyme and increase its activity. In this study, the production potential of gamma aminobutyric acid by Lactobacillus brevis PML1 in MRS medium was investigated. In order to optimize the fermentation process, culture medium containing MSG (1, 3 and 5%) was examined at 24, 48 and 72 hours. after fermentation, thin layer chromatography method was used to identify GABA produced by bacteria. Spectrophotometric method was used to quantify the bands in thin layer chromatography. The results of studies at the level of 95% significance showed that the optimal treatment included a culture medium containing 5% monosodium glutamate and a time of 72 hours at 37 ° C, in which the amount of GABA production was approximately 300 ppm; Therefore, the desired strain not only has the potential to produce gamma aminobutyric acid under normal conditions (control sample) but also by adding different percentages of monosodium glutamate to the culture medium, the amount of this production can be increased.
Volume 19, Issue 125 (July 2022)
Abstract
Paste, as one of the main tomato products, has always been of great importance in the food. About 5% (w/w) of the entering the factories, despite their high nutritional and technological value, is discarded as waste. This study aimed to investigate the effect of adding different levels of tomato peel and calcium chloride and replacing the homogenization process with the colloidal mill on the properties of tomato paste through response surface methodology (RSM). The results of this study showed that the use of tomato peel caused a significant increase in the amount of total solids, water-insoluble solids, fiber, consistency and precipitate weight ratio (p <0.05). Applying a three-step homogenization process with a colloidal mill improved the viscosity of the product due to its effect on the properties of suspended particles of the paste matrix, including a significant size reduction, change in particle size distribution and increase surface area. Calcium chloride significantly increased the consistency of the product by reacting with the pectin in the paste and forming a gel network. Microscopic analysis of the samples showed that by increasing the number of homogenization steps from one to three and adding the tomato peel, the matrix uniformity increased and a dense structure was obtained. Creating new peaks and changing the peaks’ intensity at the ATR-FTIR spectrum confirmed the binding of calcium chloride and the fiber distribution in the paste network. The results of this study showed that tomato peel can be used as a consistency-enhancing compound in tomato paste and not only prevent the discarding of a large part of this valuable compound, but also create good added value for the food industry.
Volume 19, Issue 128 (October 2022)
Abstract
In this study, the extract of Hypericum Perforatum aerial organs was prepared by hydro alcoholic solvent and the extract was coated in calcium alginate nanoparticles and the antimicrobial properties of the extract and nanoparticles on four gram-positive, gram-negative yeast and mold groups were investigated and Nanocapsules containing extract were evaluated on the shelf life of white cheese. To prepare Nano-extracts, the emulsion production method of alginate-calcium Nanocapsules containing the extract was used. The production of Nanocapsules containing the extract was done by adding calcium chloride nanoparticles to the alginate Nanoemulsion containing the extract in a ratio of 1 to 6 for 4 hours. To prepare the cheese, Staphylococcus aureus, Escherichia coli, and Candida albicans yeast are inoculated separately into the milk at a rate of 103 CFU / ml and then added calcium chloride, Rennet enzyme, extract and Nanocapsules containing extract to milk were done and the microbial properties of the cheese samples were evaluated on the day of production and up to seven days after. The results of particle size determination, particle size dispersion index, and potential and efficiency of encapsulation for the production of Nanocapsules containing Hypericum Perforatum extract and its microscopic examination confirmed the production of nanoparticles with appropriate efficiency of encapsulation. Also, the results showed that for all three microorganisms tested, the sample containing Nano-extract was able to reduce about one logarithmic cycle of the inoculated microorganism and during the shelf life of gram-positive, gram-negative and yeast had a downward trend (P <0.05). The results of the present study showed that using plant extracts containing antimicrobial compounds such as extracts of aerial organs of Hypericum Perforatum plant, especially in Nanoparticle and in appropriate quantities, as an alternative to synthetic preservatives, produce a healthy food product and with longer shelf life, it will be possible.
M. Sarabi, E. Abdi Aghdam,
Volume 20, Issue 2 (February 2020)
Abstract
The advantages and disadvantages of using gasoline and NG as single-fuel is a challenge for researchers in development of SI engines. Singular utilization of these fuels results in some advantages and disadvantages from economics, thermodynamics, pollution and development aspects and make it difficult to prefer one to the other. Assuming that using combination of the fuels can modify the output results, in the present research, different combinations of 100, 90, 75 and 60% gasoline and the rest of natural gas, designated as G100, G90, G75 and G60, were investigated in a SI single-cylinder engine at running at 1800rpm, 9 compression ratio and stoichiometric equivalence ratio. After collecting and processing in-cylinder experimental data in the combinations and different spark advances and their experimental data processing, consecutive cycle-to-cycle data were extracted and analyzed with engine output data. First, optimum spark advance of each combination was determined and then, the combinations were compared at their spark advances. The results revealed that increasing natural gas fraction in combination causes substantial reductions in standard deviation, σ, and coefficient of variation, COV of IMEP, so that σ and COV of G60 reduced by 51.6% and 49.2%, respectively, in comparison with G100. Reducing the gasoline presence in combination, the amount of CO2, NOx and HC reduced except G90 which have the higher HC and NOx, whereas, CO amount in G90 decreased to the lowest level. Also, no satisfactory performance was observed in the G90 combination.
Volume 20, Issue 5 (7-2018)
Abstract
The present study aimed to evaluate effectiveness of Superheated Solvent Extraction (SSE) compared with instant Controlled Pressure Drop (DIC) assisted Solvent Extraction (DIC-SE) on total phenolic, flavonoids, and anthocyanins compounds from pomegranate peels. The effects of temperature, extraction time, and water:ethanol ratio for SSE method, and temperature and heating time for DIC-SE were studied. The highest phenolic compounds, flavonoids, and extraction yields by SSE was achieved at 160˚C, ethanol: water 50:50 and 20 minutes, subsequently in the DIC-SE, the most effectiveness was approached at 150˚C for 5 seconds (P< 0.05). The SSE improved the total phenolic compounds (563.16±1.04 mg g-1), anthocyanins (285.11±1.02 mg 100 g-1), extraction yield (68.7%) and shortened the extraction times compared to DIC-SE, but flavonoid content was more in DIC-SE extract (439.07±0.05 mg g-1). Based on HPLC analyses, gallic acid was not detected in any of the obtained extracts, but the amount of ellagic acid and punicalagin A and B in DIC-SE extract was higher than SSE. The current study clearly shows that the SSE is an effective extraction method to obtain phenolic compounds and the DIC is an advantageous pretreatment for extraction of flavonoids from pomegranate peels.
Volume 22, Issue 158 (April 2025)
Abstract
Paenibacillus polymyxa is one of the microorganisms that has the ability to produce extracellular exopolysaccharides and antibiotics. Several factors, including culture medium content, carbon and nitrogen sources, pH, temperature, air velocity, and culture conditions, have an effect on the growth and production of higher cell mass, as well as the production of microbial metabolites. The purpose of this study was to investigate the growth rate of P. polymyxa in a culture medium containing molasses and to screen five components of the culture medium along with four factors of the fermentation conditions using the Plackett -Burman method to maximize cell mass production. The results showed that among the investigated variables, molasses brix, time, percentage of inoculation, amount of ammonium sulfate, stirring speed, and the amount of glucose and urea, as a first-order equatino, had a significant positive effect on bacterial growth and biomass production. Molasses brix medium was found to be more effective than other variables; however, pH and the amount of low-use elements had a negative effect on cell growth. The findings of this study indicated that molasses-based culture medium can be used as a cost-effective and suitable option for the growth of P. polymyxa.
Volume 28, Issue 3 (7-2021)
Abstract
Masjid i-Kabud was built upon the order of Jahan Shah, the ruler of the Kara Koyunlu dynasty, in Tabriz, Northwest Iran. This building is among the most important remains of Islamic architecture and has repeatedly been the object of research by historians of architecture. While the configuration of this building finds a corresponding prototype in Timurid Iran, in the view of a wider audience the construction purpose of this building conceptualizes the theme of Anatolian architecture. Thus, there remain several controversies about the inception of architectural layout that need to be further explored. Using a comparative-analytical method, the aim is to trace back the architectural predecessors of Masjid i-Kabud. Unlike recent studies that attest a Perso-Ottoman interaction in shaping this monument, material evidences confirm beyond any doubt that this was built under the guidance of a master-architect who came from Central Asia a short time before its construction in Tabriz, a grand new capital. According to the results, it is possible to point out a general architectural consistency from the Timurid Empire to the Turkoman era that is largely visible in this building: a tomb in the rear of the central dome aligned with an axial portal, while auxiliary rooms surrounding the main dome on the three sides is a modification of the old traditional Iranian form and might have a close relationship with changes occurring within the religious doctrine in providing adequate space for pilgrimages and educational purposes.