نشریه مهندسی بیوسیستم ایران
سال پنجاه و دوم شماره 1 (بهار 1400)

Shallot (Allium stipitatum) is one of the native plants of Iran with antioxidant and antimicrobial properties. In this study, the effect of microwave method (in the powers of 450, 600, 750 and 900W) on drying characteristics of Shallot was investigated. Process kinetics study showed that among 10 common mathematical models, two term model was the best choice in the power range of 450 to 900W. As the power of the microwave increased, the drying time was decreased and its drying rate was increased. The minimum drying time was 18 minutes at 900 W, which was 95.5% less than hot air drying time (400 minutes). The results showed that with increasing microwave power, the diffusion coefficient increases and the activation energy decreases. The maximum effective moisture diffusivity was obtained 1.2×10-7 (m2/s) and the minimum activation energy was obtained 5.3 W/g for microwave power of 900 W. The optimum power was 450W in terms of total color change (∆E) and 900W in terms of browning index (BI).

Hyperspectral imaging technique as a new and efficient method is applied for detecting infection in agricultural products. It was used for classification of healthy and infected pistachio kernels by Aspergillus flavus fungus with and without considering infection stages. Two different fungus isolates, R5 and KK11 with and without capable of producing aflatoxin, respectively, were individually used to infect the pistachio kernel samples. From 960 to 1700 nm, three effective wavelengths of 1090, 1280, and 1700 nm were selected by principle component analysis method. After feature extraction, K-fold cross validation, support vector machine, and artificial neural network methods were used for classification. The results showed that the classification accuracy of the K-fold cross validation method was higher for classifying the healthy and infected pistachios without considering the infection stages and isolate type (99.71%). The maximum accuracy of the developed algorithms in classification of isolate type and infection stage was obtained as 69-91%.

In this study, the energy consumption and environmental effects of pumpkin production in Boroujerd county have been investigated. To evaluate energy in pumpkin production, energy ratio (ER), energy productivity (EP), energy intensity (EI) and net energy gain (NEG) indices were obtained. The values ​​of 1.6, 2.1 kg.MJ-1, 0.4 MJ.kg-1, 10,952 MJ.ha-1 were obtained, respectively. The results showed total input and output energy was 16,191 and 27,143 MJ.ha-1, respectively. Chemical fertilizers and diesel fuel had the highest energy consumption among the inputs. Environmental effects were assessed with a life cycle approach using the CML model. Nitrogen fertilizer with 48% in acidification and pesticides with 90% in global warming accounted for the highest share of these impact categories. It is suggested that the use of fertilizers and chemical pesticides be managed by educating farmers to save energy, economic and environmental benefits.

Wheat straw is widely used for animal feed and biorefinery to sugar production. However, cellulose, which is the major source of sugar, is protected by lignin. Ozone is a powerful oxidizer that can deconstruct lignin and makes cellulose accessible to enzymatic digestion. The aim of this study is the delignification of wheat straw using ozonolysis technology as a green, environmentally friendly, and energy-efficient process. Modeling and optimization were performed by response surface methodology and the effects of five factors including ozone production rate (1, 2, and 3 g/h), reaction time (15, 30, and 45 min), the flow rate of ozone/oxygen (0, 3, and 6 L/min), moisture content (100, 200, and 300% w/w) and urea (0, 1.5, and 3% w/w) were investigated. The results of this study showed that the highest delignification (50%) was observed in the highest levels of ozone amount, time, flow rate, urea, and the lowest level of moisture content. The flow rate and moisture content factors were the most contributing factors in the delignification process with 36 and 20%, respectively. Under optimal conditions, 49.8% of delignification was obtained at an ozone amount (3 g/h), time (45 min), flow rate (5.7 L/min), moisture content (100% w/w), and urea amount (3% w/w) with a desirability index of 0.99. The response surface method creates a desirable fitness between the experimental and predicted responses with R2=0.90. The results showed that the ozonolysis process using the proposed factors can be used to delignification of wheat straw.

In this study, an ultrasonic-thermal concentrator under vacuum conditions was fabricated and the effect of concentration variables for watermelon juice concentration was optimized. Concentration temperature process in three levels (40, 50 and 60°C), vacuum pressure in three levels (20, 40 and 60kPa) and ultrasonic waves power in three levels (36, 60 and 84W) were conducted. Statistical analysis of data and optimization of concentration process were performed using response surface method and central composite design. Results showed that the increase of concentration temperature has a positive effect on concentration process time and total energy consumption and negative effect on lycopene content and the total color difference. Decrease of vacuum pressure to caused increased lycopene content and decrease the total color difference, concentration process time and total energy consumption. Also increased ultrasonic waves power caused increase in lycopene content, total color difference, total energy consumption and decrease in concentration process time. Optimization of watermelon juice concentration point was obtained on concentration temperature 40°C, vacuum pressure 20 kPa and ultrasonic waves power 46.5W. Optimal values of response variables in this condition include lycopene content, the total color difference, concentration process time and total energy consumption in equal order 238 mg/kg, 25.7, 94.5 min and 0.727 kWh. The use of ultrasound waves along with the concentration temperature and vacuum pressure could have positive results on the watermelon juice concentration process.

Drying is one of the most important methods of food processing. In this study, the effect of different drying methods, like hot air drying (40 and 50 °C) and microwave drying (180 and 360 W), on physical, chemical and antioxidative properties of peel of sanguine orange (Citrus sinensis) was investigated. D-limonene (72.3-78.5 percentage), β-Myrcene (6.9-8.0 percentage), Linalool (1.3-4.6 percentage), and α-Pinene (1.7-2.7 percentage) were main components of essential oil of sanguine orange peel. The different drying methods reduced or increased some components. Drying decreased Lightness, yellowness, and redness of sanguine peel powders. Drying brought about increase in the yield, bulk density, phenol content, and antioxidant activity of essential in comparison with fresh samples. On the other hand, microwave drying 180W showed the highest amount of phenol, DPPH radical scavenging activity and ferric reducing antioxidant power (FRAP) tests. Therefore, considering about the quality of essential oils, the use of microwaves for drying sanguine oranges could be suggested.

In this study, batch series of laboratory-scale anaerobic digesters at 35 and 55 ° C were used to investigate the production of biogas from dairy effluents and reduce its pollution. Dairy effluent sludge with ratios of zero, 10, 20, 30, 40 and 100% was used for inoculation. The interaction effect of sludge percentage and temperature at the level of one percent on the volumetric indices of biogas production was significant for the amount of initial volatile solids, volatile solids removed and chemical oxygen demand removed at the level of one percent. With increasing sludge percentage, the amount of biogas produced per initial volume increased for the removed COD but decreased for the initial volatile solids. The highest biogas production efficiency was obtained based on the removed volatile solids at thermophilic temperature and 40% sludge ratio, with the removal of 47.7% volatile solids and 266.5 ml per gram of removed volatile solids. According to the results, the amount of biogas production at mesophilic temperature, in lower proportions of added sludge, is more than the amount of gas produced at thermophilic temperature, and due to the low volume of sludge production in the dairy industry and higher energy consumption under thermophilic conditions, anaerobic digestion and biogas production are more favorable at 35 ° C. The results also showed that by anaerobic digestion of each m3 of dairy effluent, 20.83 MJ of heat energy can be produced.

In this study, the best time to harvest olive oil of Roughani variety in Golestan province was determined by examining the physicochemical properties in the months of October, November and December. The highest fruit-to-core ratio and the amount of oleic acid (62.60%) were obtained in the third harvest period. After that, palmitic acid (18.66%), linoleic acid (16.33%) and stearic acid (3%), respectively, accounted for the largest amount of fatty acids. The ratio of oleic acid to linoleic acid, the amount of acidity, and the amount of total phenol increased during fruit ripening. The highest sterol compound was beta-sitosterol (from 83.22 to 90.02%), which, along with peroxide ((2.05 to 7.05 (meqO2/kg oil)), declined over three harvesting periods. Due to increasing the ratio of oleic acid to linoleic acid and also the high ratio of cholesterol to stigmasterol, the best time to harvest olives for Roughani variety of Golestan province was determined in the third period of harvest (December).

Purslane is an important vegetable and medicinal plant that is produced and consumed in the southern regions of Iran. Recently, special attention for processing and pharmaceutical industries of purslane has been paid. Seed separation procedure, is one of the most important and difficult steps in purslane processing. In this Research, a seed threshing unit for mechanization of purslane seed harvesting, was built, evaluated and tested. The most important components of this thresher are the shaft, the rubber thresher and the rubber concave. This machine was designed and manufactured and then the losses were determined. The losses evaluation was carried out under randomized factorial analysis. Experiments were conducted at three levels of drum speed (35, 80 and 120 rpm), feed rate (2, 3 and 5 kgmin-1) and sieve swing speed (180, 200, 220 rpm). The results showed that the impact of drum rotational speed, oscillation of sieve and feed rate on seed separation percentage and unopened sheath is significant at 1% level. The lowest amounts of losses (9.39%) were obtained at 80 rpm drum rotational speed and 2 kgmin-1 feed rate and also 200 rpm sieves swing speed, respectively. Highest percentage of losses (27.83%) was obtained at 120 rpm drum rotational speed, 5 kgmin-1 feed rate and 220 sieves swing speed, respectively. Threshing efficiency at lowest level of machine losses, was 92%. Maximum output capacity (at lowest level of losses) and energy consumption were obtained 2.7kgh-1 and 14084 KJ, respectively.

Nowadays, with progress in different sciences and entering logging software and Decision Support Systems, decision has been deviated from trial and error in agriculture mechanization and aimed to predict prospective and targeted accordingly. Therefore, in this research, the Analytic Hierarchy Process (AHP) with the help of EXPERT CHOICE11 software was employed to select the best kind of sprayer for usage in citrus gardens of Mazandaran. Four different sprayers including Motorized Backpack sprayer, Atomizer sprayer, Wheelbarrow sprayer and Air blast sprayer were evaluated in this study. The criteria of selection consisted of the tank capacity, costs, spray quality, field capacity and amount of consumable solution per hectare. The importance of spray quality, amount of consumable solution per hectare, costs, tank capacity and finally field capacity were equal to 0.481, 0.302, 0.102, 0.073 and 0.042, respectively. The atomizer sprayer is selected and introduced with 0.504 final value as the most appropriate choice option. Inconsistency ratio was calculated equal to 0.04 that is acceptable amount in satays' opinion.

Mathematical modeling is a powerful tool for prediction of Ion Sensitive Field Effect Trnsistor (ISFET) response and optimization of its functional parameters. In this study the optimal values of drain current, drain voltage and initial concentrations of substrate and enzyme parameters were determined to achieve maximum of ISFET response for detection of Aflatoxin B1 (AFB1). Optimization was performed by using Genetic Algorithm (GA) and based on numerical solution of ISFET governing differential equations by means of Finite Element Method (FEM) and COMSOL Multiphysics software. The objective function of GA was defined through substituting simulated model by Artificial Neural Network (ANN) metamodel. The results showed that ISFET simulated FEM model has a MAPE equal to 1.06 % in prediction of ISFET response compared with experimental results. With FEM model, 1296 virtual experiments were simulated to achieve necessary data base for train ANN metamodel. By evaluation of different ANN structures, trained ANN with 4-45-1 structure was selected which has MAPE equal to 0.04 %, 0.07% and 0.05% at train, validation and test phase respectively. ISFET optimization results states that by using of GA determined optimal values of drain current, drain voltage and initial concentrations of substrate and enzyme parameters, extremum response of ISFET equal to 44.44 % was achieved.

In spite of their advantages in the treatment of animal diseases, veterinary drugs can remain in foods of animal origin and cause considerable threats to the consumer health. Antibiotics, anthelminthics, Anticoccidial drugs, and nonsteroidal anti-inflammatory drugs are the major veterinary drugs that can contaminate food products. Food processing can be considered as a strategy for the removal of drug residues in foods. Awareness of drug residues and their reductions during different processes can be important in terms of the consumer health. This paper, therefore, reviews the literature on veterinary drug residues in foods of animal origin, including milk and milk products, eggs, meat, and meat products, as well as the effect of different processes on the stability of these drug residues. To this end, all related articles and theses were reviewed from national (SID, Irandoc, and MagIran) and international (Science Direct, Google Scholar, Scopus, and Pub Med) databases. According to reviewed studies, most of foods of animal origin in Iran were contaminated with antibiotic residues. In other countries, foods of animal origin contained different levels of drug residues. Based on scientific findings, heat processing could reduce the residues of tetracycline, macrolides, aminoglycosides, and sulfonamides in milk, residues of tetracycline, ciprofloxacin, enrofloxacin, sulfanilamide, and chlorpyrifos in eggs, and residues of oxytetracycline, ampicillin, chloramphenicol, sulfonamides, and anthelminthics in meat products. The microwave, freezing, and fermentation processes were also effective in the reduction of drug residues in foods.