ayat mohammad razdari

The use of veterinary drugs, including antibiotics, leads to their aggregation in livestock products such as meat, milk, and eggs. Therefore, rapid, accurate and economy detection of antibiotics for monitoring of food security is necessary. In the current research, a biosensor based on pencil graphite electrode modified with grapheme and gold nanoparticles for detection of β-lactam antibiotic in milk samples was fabricated. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques for evaluation of surface electrode changes were applied. Under optimal conditions, using the EIS method specified that in the ranges of 1×10-15 to 1×10-5 M, The relationship between charge transfer resistance and the logarithm of antibiotic concentration was linear and the regression equation was y=119x+2600 (R²=0.977). The current peaks in three measures were achieved as 18, 19.5 and 19 µA. calculation of relative standard deviation (RSD=3.31%) that indicated an acceptable repeatability for biosensor. For investigating of reproducibility, RDS for current peaks was 8.94% that showed a good reproducibility for biosensor. The selectivity of a biosensor in the presence of three antibiotics including streptomycin, tetracycline, and sulfadiazine was checked. Data of charge transfer resistance was indicated that biosensor has non-significant the response towards the other antibiotics. The results showed that biosensor response decreased by 6% after 18 days compared with the first day, which indicates good stability for biosensor. The percentage recovery range for milk samples at concentrations of 1 × 10-9 and 1× 10-11 M for two samples of cow and sheep milk was obtained as 92.3 to 104% in three replications, which indicates an acceptable recovery range for proposed biosensor.

Determination of antibiotic residues in food including honey is very important. To data, various methods have been developed to determination of antibiotics in honey and other animal products. In recent years, the fabrication of electrochemical biosensors in combination with nanomaterial has attracted much attention. In the present study, an impedometric biosensor based on nanomaterial including reduced oxide grapheme (RGO) and gold nanoparticles (GNP) was developed for antibiotic detection of tetracycline in honey samples. Cyclic voltammetry and electrochemical impedance spectroscopy techniques were used to evaluate the working electrode surface. Peak current values in different modes were 0.034, 0.048, 0.09, 0.020 and 0.015 μA for unmodified electrode, RGO, GNP, aptamer and antibiotic, respectively. Biosensor characteristics including reproducibility, reproducibility, stability, and selectivity were evaluated using resistance charge transfer data, the results showed that they were acceptable. In order to calculate recovery percentage, concentrations of 1×10-9 and 1×10-11 M were prepared from tetracycline and injected into honey samples. The results showed that the proposed biosensor provides 94.1% to 104.4% recovery rate for tetracycline in honey samples.

Quantitative detection of drug residues in animal food stuffs is very important. Excessive use of veterinarian veterinarians, like antibiotics are a serious threat to consumers, due to the residence of livestock products such as meat, milk, eggs. Rapid detection of antibiotics is essential by using an efficient, fast, affordable, and specific tool for risk reduction and food safety control. In the present study, an aptasensor based on pencil graphite electrode modified with nanomaterial including grapheme and gold, for rapid detection of tetracycline antibiotic was developed in milk samples. Cycle voltammetry and differential pulse voltammetry (DPV) techniques were used for response evaluation of aptasensor. In order to modification the graphite pencil electrode, the scanrate (40 mV/s) and the number of cycles (10) and immobilization time of graphene (90 min) were optimized. Under optimum conditions, using differential pulse voltammetry technique was found to increase linearly in the range of 1 × 10-12 to 1 × 10-5 M, with increasing concentration (R² = 0.985). The detection limit of the aptasensor was found to be 1.4× 10-13 M. A review of functional characteristics including repeatability, reproducibility, satability, and selectivity suggests acceptable performance for aptasensor. Overall, the fabricated aptasensor has efficiency required to detect tetracycline in milk samples.

Tomato is the second most important crop in the world, which is often consumed freshly. One of the most importance tomato products is paste that considered being the stuffing ingredient in Iranian foods. Therefore, the safety of tomato paste is so important. The aim of this study was diagnosis adulteration in tomato paste. For this purpose, olfactory machine system based on five gas sensors (TGS2600, TGS2620, MQ3, TGS880, TGS2610) was constructed and its potential was evaluated in determining the different levels of pumpkin adulteration in tomato paste (0, 5, 10, 15 and 20%). Pure tomato paste detection from adulteration samples was based on the samples smell in the head space and the receipt of smell by sensors. The principal component analysis (PCA), linear discriminant analysis (LDA), support vector machine (SVM) and partial least squares (PLS) were used to classify and analyze the extracted features of the sensor response. Results of PCA and PLS indicated that 99 and 94 percent of data variance was covered by two main components. TGS2610 and MQ-3 sensors and TGS880 sensor had the highest and lowest application in detection of tomato paste adulteration. The accuracy of the classification by the LDA method was 79.7%. The polynomial function with accuracy of 77.78% of the training and 76.66% validation in the C-SVM method and the radial base function with a precision of 98.8% of the training and 88.14% of Validation in the Nu-SVM method had the highest classification accuracy. In total, the olfactory machine system had acceptable performance in separation of different levels of adulteration.

Tomato is one of the most important vegetable crops in Iran and is grown commercially in every state in the country. Tomatoes are climacteric in nature and climacteric fruits submitted to gamma irradiation exhibit a delay of ripening. In the specific case of tomatoes, irradiation generally delays ripening when the treatment is applied at the pre-climacteric stage. Mechanical properties are very important quality property in tomato. Determination of the storage time effect on the evolution of this quality is a desirable objective for producers, distributors and marketing agencies, who need reliable firmness measuring instruments for commercial purpose. Previous studies carried out by different researchers show that impact techniques can be used to evaluate firmness of fruits successfully. Quick and nondestructive methods for measuring texture are critical for controlling postharvest quality of crops and fruits. Polymer films are ubiquitous in the food industry, fulfilling a range of functions including a significant role in reducing food waste. Also, it can be possible to extend shelf-life with some coatings, including polymer films.
In this study, tomatoes were irradiated in Atomic Energy Organization of Iran. For irradiation of samples, cobalt 60 (Gamma Cell 220) was used. The samples were irradiated with doses of 0 (control), 0.25, 0.5 and 1 kG, then transferred to the laboratory and kept in a refrigerator at 6 ± 1 ° C and 65 ± 4% relative humidity for 21 days. In order to pack, polyethylene film with medium density (thickness of 0.3 mm and depth and width, respectively, 6.5 and 19 cm) were obtained from the Iranian Polymer Research Institute. Experiments were performed on samples coated with polyethylene film in 7 days intervals. Acoustic tests were performed using Impact Test System. The system was covered with aluminum chamber and inside with wood and clouds. The system was internally equipped with the sample location on the floor, the impact mechanism and the receiver of the signal. In this audio excitation system, samples were taken with the help of a blow. By applying a blow to the sample surface, the audio signal was sent to the sample and then measured by a receiver placed at a distance of 7 mm from the sample. The experiments were performed every 7 days. During the experiment period, the physical and mechanical properties of the samples were measured. Data were analyzed using SPSS.20 software. Correlation between hit parameters and firmness of penetration test were checked out using regression in Excell .2013 software, and predicted a suitable model for determining the firmness of tomato.
The results showed that after 21 days of storage time, the amount of mass and density for irradiated sample with a 0.5 kGy dose in polyethylene film compared to control sample (uncoated) decreased to 22.53 and 12.34 %, respectively, and had more resonant frequency to 26.58%. Also, irradiated sample with a 0.5 kGy dose in polyethylene film compared to samples irradiated with doses of 1 kg and non-irradiated samples in polyethylene film had higher modulus of elasticity and firmness to 37.74, 26.48 % and 25% and 18.12%, respectively. The maximum penetration force in destructive testing had strong relationship with the parameters obtained from Acoustic test such as resonant frequency, Strength index and Modulus of elasticity with a correlation coefficient to 0.893, 0.913 and 0.886, respectively. Combination of polyethylene film with 0.5 kG irradiation on the changes in mass and volume, strength coefficient, resonance frequency, elasticity modulus and rigidity obtained from the impact test have the best results. Also, combination of polyethylene coating and 21-day storage time on mass and volume changes, strength coefficient, resonant frequency, elasticity modulus and stiffness from the impact test reduced the storage performance. According to the results of this study, by irradiation of a sample of tomatoes with a 0.5 kG and using a polyethylene film, it can be stored with a slight change in stiffness and texture for a period of 21 days, and possibly more, which causes increase the shelf-life in the warehouse, reduce storage costs in the warehouse by conventional methods and increase the possibility to export. As a summing up, irradiation in combination with Polyethylene films is a good way to preserve tomatoes tissue and Acoustic textures is a useful way to be replaced with Penetration test

According to current statistics, a quarter of the food produced in the world is destroyed after the harvest. These corruption is imported in various stages of production, storage, distribution, marketing, and finally in the consumer goods. Food processing irradiated with gamma rays and maintenance products, quality food to maintain a long period of time. Golden Delicious apple variety is yellow, was purchased from AEOI and then 100 number were collected randomly with an average size (120 to 180 g). Apples were kept for a week in the cold (4 ° C). Samples were packed in sterile plastic bags, to irradiation. For irradiation of samples was used cobalt-60 source (Gama-cell 220). Samples doses were zero (control), 0.5, 2 and 5 kGy of irradiation, then were stored for 4 days at 4 ° C. Apple sheets with a thickness of 4 mm was cut cutting products in three at 50, 65 and 80 ° C dry test was carried out using the oven. According to the study, irradiation of food, chemical and physical properties of apples maintain. With increasing irradiation dose and temperature drying oven, moisture content in the samples of moisture loss and weight loss increases. The main effect of irradiation dose and temperature drying on the index at the level of 0.05%, significant. By increasing the drying temperature in the oven, the rise because of this phenomenon, the moisture content of the tissue sample and is in the process of shrinkage. Finally, with increasing radiation dose drying temperature, water absorption capacity increases. So the method of irradiation and finally drying with appropriate temperature drying can be used to preserve food quality.

By irradiation as Food processing method, Food quality is maintained and control of microorganism causes prevention of corruption. Simultaneously, Methods of drying, which leads to maintaining the quality and texture, are used. In this study, optimal conditions were determined by drying gamma rays irradiated potatoes with response surface method. For sample, the source of 60 Co irradiation (Gamma Cell 220) was used. Samples with 0, 2, 5 and 8 kGy doses were irradiated. Drying using microwave power at 200, 400 and 600 W and in three thicknesses of 5, 7 and 9 mm of sample was performed. Optimal conditions for radiation dose of 5 kGy, sample thickness of 7 mm and a microwave power of 400 W and L*, a*, b*, color changing, hue angle, Croma and browning index were proposed to 57. 87, -0. 95, 42. 19, 10. 73, -1. 53, 42. 22 and 113. 59, respectively. In addition to the effects of radiation variables, the thickness of the sample and the microwave drying effect on indicators such as L*, a*, b*, browning index, Croma and hue angle was investigated. Type text or a website address or translate a document. Did you mean: ÔÑÇیØ Èåیäå ãÑÈæØ Èå ÏÒ ÑÊæÏåی 5 ˜یáæ یÑی¡ ÖÎÇãÊ äãæäå 7 ãیáی ãÊÑ æ ÊæÇä ãÇی˜Ñææیæ 400 æÇÊ æ ÈÑÇی þL*ý¡ þa*ý¡ þb*ý¡ þÊÛییÑÇÊ Ñ䐡 ÒÇæیå åیæ¡ ˜ÑæãÇ æ ÔÇÎÕ Þåæå Çی ÔÏä Èå ÊÑÊیÈ¡ 87/57¡ 95/0-¡ 19/42¡ 73/10¡ 53/1-¡ 22/42 æ 59/113 þیÔäåÇÏ ÔÏ With increasing irradiation dose, increasing the thickness of the sample and the microwave power, the color index decrease, Hue angle color and color density increases and decrease, respectively. Finally, using the neural network model, drying of irradiated potato was modeling and ability of the model to predict of the color changes in regression and response surface method was compared. In this comparison the neural network model was capable for prediction higher than the regression model ( ).

Irradiation is a modern method of food preservation. In this research were evaluated irradiation dose effect, shelf-life and storage time of on some qualitative and rheological properties of potatoes tuber. The samples were purchased from the store's Atomic Energy Organization and were stored for a week in the cold (4°C) in order to prevent chemical changes in the tissues. In order to samples irradiation was used cobalt-60 source (Gamma-cell 220). The samples were irradiated with 0 (control), 2, 5 and 8 kGy and then were storage for 150 days at a temperature of 6°C and at ambient temperature (18°C). Samples dry matter and starch content was higher for doses of 2 kGy and stored at a temperature of 6°C to 22.01 and 12.09 %, respectively. Geometric mean diameter and sphericity values ​​decreased with increasing radiation dose to 23.27 and 8.39 % and the dose of 8 kGy irradiated samples had the lowest values to 40.12 and 76.41 %, respectively. Also, a *, b *, color changes and BI increased by increasing the radiation dose to 2.9T 3.2T 5.13, 4.97 % and L* decreased to 2.14%, too. Moreover, three component model was calculated using by Maxwell Model and results show that with increasing dose of irradiation and temperature, relaxation stress decreased and relaxation time increased to 39.96 and 27%, respectively.

Agriculture is a complex system science and the knowledge of it is consisting of much concepts and relationships. Examinations in connection with site-specific farming have been carried out by our institute since 1998. Precision farming is a way of agricultural production, which takes into account the in-field variability, a technology where the application-seeding, nutrient replacement, spraying, etc. has taken place to act on the local circumstances of a given field. The geographic information system (GIS) created by computing background makes possible to generate complex view about our fields and to make valid agro technological decisions. With the advent of the satellite-based Global Positioning System, farmers gained the potential to take account of spatial variability. Our goal was to compare two systems for marking out further research tasks, because in some cases there have been misunderstandings among the researchers, and the information provided by given companies seems to be complicated for potential users. This article provides an overview of worldwide development and current status of precision agriculture technologies and Application of GIS and GPS in Precision agriculture.

In spite of the technologies developed during the last decade, the level of food loss is still high and is reported in many countries. According to the United Nations, more than 30 per cent of the mortality rate world-wide is caused by alimentary diseases. The desire of most countries to make food safer for consumption requires better food preservation and production techniques. In this regard, irradiation is an interesting alternative to be considered Food irradiation is a process exposing food to ionizing radiations such as gamma rays emitted from the radioisotopes 60Co and 137Cs, high energy electrons and X-rays produced by machine sources. Some agricultural products are important commodities in international trade. The trade of these products is often seriously hampered by infestation of several species of insects and mites. The presence of parasites, some microorganisms, yeast and moulds are also the source of problems, sometimes directly or indirectly through toxin formation in the food products. Irradiation alone or combined with others processes can contribute to ensuring food safety to healthy and compromised consumers, satisfying quarantine requirements and controlling severe losses during transportation and commercialization. Depending on the absorbed radiation dose, various effects can be achieved resulting in reduced storage losses, extended shelf life and/or improved microbiological and parasitological safety of foods. However, hindering factors in the way of commercial implementation of the food irradiation process are politics and consumer advocacy. This paper reviews the application of irradiation for preserving some fruit and vegetables.

Wheat as the most main food for the world and a strategic product has a major role in people's food supply. Average of wheat growing areas in Iran is 6.65 million hectares and more than 374 thousand hectares of wheat annually in Lorestan province is planted. In this study, conventional methods in the measurement of crop losses, John Deere and Behroozi-Lar method as proposed approaches was considered and the real waste of dry land wheat harvest, in 2011 in central part of the Khorramabad Township, in the center of Lorestan province, was measured. Using three Factors-factorial design, in field sampling, pre-harvest losses (normal), cutting platform Losses, unit pounding Losses, the unit separate and distinguishable Losses (end of combine) was measured and total farm losses were also determined. For statistical analysis of data, SPSS software was employed and for comparison of means, Duncan's test was used. The results showed that the average wheat harvest losses in Khorramabad has been 5.21% including 0.65% normal losses and 4./56% losses of combine.

Agriculture is a complex system science and the knowledge of it is consisting of much concepts and relationships. Examinations in connection with site-specific farming have been carried out by our institute since 1998. Precision farming is a way of agricultural production, which takes into account the in-field variability, a technology where the application-seeding, nutrient replacement, spraying, etc. has taken place to act on the local circumstances of a given field. The geographic information system (GIS) created by computing background makes possible to generate complex view about our fields and to make valid agro technological decisions. With the advent of the satellite-based Global Positioning System, farmers gained the potential to take account of spatial variability. Our goal was to compare two systems for marking out further research tasks, because in some cases there have been misunderstandings among the researchers, and the information provided by given companies seems to be complicated for potential users. This article provides an overview of worldwide development and current status of precision agriculture technologies and Application of GIS and GPS in Precision agriculture.

In spite of the technologies developed during the last decade, the level of food loss is still high and is reported in many countries. According to the United Nations, more than 30 per cent of the mortality rate world-wide is caused by alimentary diseases. The desire of most countries to make food safer for consumption requires better food preservation and production techniques. In this regard, irradiation is an interesting alternative to be considered Food irradiation is a process exposing food to ionizing radiations such as gamma rays emitted from the radioisotopes 60Co and 137Cs, high energy electrons and X-rays produced by machine sources. Some agricultural products are important commodities in international trade. The trade of these products is often seriously hampered by infestation of several species of insects and mites. The presence of parasites, some microorganisms, yeast and moulds are also the source of problems, sometimes directly or indirectly through toxin formation in the food products. Irradiation alone or combined with others processes can contribute to ensuring food safety to healthy and compromised consumers, satisfying quarantine requirements and controlling severe losses during transportation and commercialization. Depending on the absorbed radiation dose, various effects can be achieved resulting in reduced storage losses, extended shelf life and/or improved microbiological and parasitological safety of foods. However, hindering factors in the way of commercial implementation of the food irradiation process are politics and consumer advocacy. This paper reviews the application of irradiation for preserving some fruit and vegetables.