نشریه مهندسی بیوسیستم ایران
سال چهل و ششم شماره 2 (تابستان 1394)

The main objective of this study was to investigate the environmental impacts of cotton production in Golestan province of Iran using life cycle assessment methodology. The data used in the study were obtained from cotton farmers with face-to-face questionnaire method during 2011-2012. The questionnaires included total inputs of cotton production in the region and yield weight. Environmental impacts based on three functional units (FU) including: the production of one ton biomass, generation of 1000 MJ energy and 10000 Toman net income were investigated. Environmental impacts were evaluated into seven impact categories including global warming, acidification, terrestrial eutrophication, land use, depletion of water resources, depletion of fossil resources and depletion of phosphate and potash resources. Results showed that the terrestrial eutrophication and depletion of fossil resources in terms of environmental index (EcoX) and resource depletion index (RDI) had the highest potential environmental impacts. EcoX for one ton production of cotton, generation of 1000 MJ energy and 10000 Toman net income were calculated as 0.832, 0.048 and 0.036, respectively. RDI for these three functional units were 6.825, 0.396 and 0.296, respectively.

Regarding the unique properties of camel milk, it can be used as a nutraceutical product. In this study, the effect of different variables on the quality characteristics of synbiotic yoghurt made from camel milk was studied. Independent variables (all in three levels) in this study were: β-glucan (prebiotic agent) 0 - 1 - 2%, fat content 0 - 2.5 - 5%, the amount of probiotic bacteria 0.5 - 1 – 1.5% and storage time 0 - 7 -14 days. The least amount of syneresis (0%) was obtained when the highest percentage of β-glucan (3%) and fat content (5%) were used. Least pH (pH=4.06) was observed in non-fat yoghurt (0% fat) when it was inoculated with an increased amount of probiotic bacteria (1.5%), β-glucan (2%) and time (fourteen day). The optimum viability of probiotic bacteria in yoghurt (107 cfu/mL) was obtained by increasing β-glucan and reducing fat contents at early days of storage. The highest viscosity was obtained at 7th days of storage when the highest content of β-glucan (3%) and fat (2.5%) were used. According to test panel analyses its overall acceptance and taste became better when the concentration of β-glucan and storage time increased.

The new device made in this study could calculate the proper position of tillage tools relative to the land surface at each point, and hydraulic operator set its optimum position. The optimum position of tools is calculated by depth control software developed for this device, and its input data were depth for root development. The performance of device was tested on subsoiler for precision tillage operation. The accuracy of applying the desired depth was studied in laboratory and also agricultural land. Factors considered in the laboratory were type of depth changing (increasing or decreasing) and seven steps of depth changing in the range of 0 to 350 mm with 50 mm interval. In the field test, in addition to the above mentioned factors, gear changing was also considered (gear 1, 2, 3 of Massey Ferguson Tractor). Precision deficiency for laboratory test was 3.3 percent for increasing and 3.83 percent for decreasing of depth. The precision deficiency in agricultural land was 4.19 percent for gear one, 5.19 percent for gear two and 5.78 percent for gear three. Eventually, this amount for decreasing of depth was 6.84 percent for gear one, 4.67 percent for gear two and 6.14 percent for gear three.

With the increasing world population and Limitations on arable land, increasing the yield per unit is one of alternatives human food supply. Greenhouse cultivation as one ways of increase the performance can arrive this purpose. But the energy restriction of another human challenges, So that increase the performance without considering energy consumption almost appears to be meaningless. Due to the high energy consumption in the greenhouse productions, in this study were evaluated the energy consumption and energy indices in the greenhouse cucumber productions in Tehran province. Also, the energy efficiency of firms was examined whit using Data Envelopment Analysis (DEA) method. The data for this study has been gathered through interviews from 160 cucumber producers of Tehran greenhouse in 2013. The results of this study showed that energy efficiency, energy productivity, net energy and specific energy is equal to 0.52, 0.65 kg/ MJ,-73180 MJ/ ha and 1/52 MJ /Kg, respectively. The share of direct, indirect, renewable and nonrenewable energies from total energy consumption was calculated 0.86, 0.14, 0.04 and 0.96, respectively. Also the result indicates the greenhouses are not efficiency,So that in this firms increase in input consumptions is more than production increase. Finally, this issue reduced the energy efficiency of the units.

Oil uptake is one of the most important aspects about product quality during frying. The purpose of this study was to investigate the effect of temperature on oil content of final product and its perception using empirical models. Therefore, potato stripes in specified size, after blanching were fried using a fryer equipped with thermo controller at 145, 160 and 175 º C for 60, 120, 180 and 240 seconds. For separation of various stages of process surface and core temperatures of product was measured using thermocouple and data logger. Oil of samples also extracted by soxhlet method and its variation was fitted using kinetic models (Model 1 and Model 2) in MATLAB. Models were compared by R2, RMSE and also Arrhenius equation. The results showed that the equilibrium oil content (Oeq) obtained from fitting of models has inverse relation with temperature that confirms a reduction in oil uptake with increasing of frying temperature. Statistical analysis of experimental data indicated that critical temperature for reducing of oil uptake was 160 °C. The time limitation before end of surface boiling period was estimated about 160-180 seconds.

The use of isomalt and maltitol instead of sucrose in foods has an important role in human health as controlling blood glucose levels and weight management. In this study, isomalt and maltitol instead of sucrose were used at three concentration level (75, 85, and 100%). Effects of the polyols were investigated on physicochemical properties (size of bubble cake batter, moisture content, water activity, crust and crumb color, firmness, volume and porosity) and sensory of sponge cakes. Results showed complete replacement of sucrose by isomalt and maltitol increase the size of air bubbles in the batter (p<0/05). The largest bubbles were observed in the batter contains 100 % isomalt. The highest moisture content and firmness were obtained in samples containing 100% maltitol (p<0/05).Lightness of cake crust increased with addition of polyols in cakes, while volume and porosity of cakes decreased as the amount polyols increased. In sensory evaluation, the highest overall acceptance score given to cakes containing 75% maltitol.

The potential of Vis-IR (400–1100 nm) transmittance method to assess the internal quality (freshness) of intact chicken egg during storage at a temperature of 307 oC and 25% 4 relative humidity was investigated. One hundred chicken egg samples were used for measuring its freshness and spectral collection during egg storage times (up to 30 days). Two correlation models between Haugh unit (HU) and the yolk coefficient (YC) versus the storage time were developed with the correlation coefficients of 0.86, 0.96, respectively. The latter equations showed in that aforementioned conditions egg quality decreased dramatically. Furthermore, the method has developed to acquire the wavelength features based on genetic algorithm (GA). It can solve the problem of the effective information extraction from the high-dimensional data matrix. Regression equations were developed by raw and according to the wavelength features were acquired, respectively basing on different preprocessing (SNV, MSC, FFT, as well as 1st and 2nd derivations). The result indicated that regression equations based on GA and preprocessing SNV and MSC could classify egg’s spectra in three groups while by 1st derivation preprocessing, each daily spectrum could allocate each of them into separated groups.

In this research, the effect of variety, harvesting time and fruit size were investigated on the mechanical properties of skin, density and mechanical strength. The results showed that pomegranate cultivars (Ardestani, Shisheh-Cap and Malas) had different skin thickness resulting difference in forces required for penetration of pomegranate fruit (10%). The skin of Shisheh-Cap variety was thicker than others. Mechanical strength of Shisheh-Cap and Ardestani varieties were 453 and 428 N respectively. The results revealed that Malas variety had the least strength against compression forces and it decreased (15%) with delay in harvesting of pomegranate fruit. It was shown that by increasing of fruit size, the density reduced (39%) and the mechanical strength increased (25%).

In order to improve food texture, hydrocolloids are used widely as gelling material in food systems. Wild sage seed has remarkable amounts of gum (mucilage) with good functional properties. This mucilage also improves the rheological, textural and functional properties of foods. In this study the effects of different drying methods including hot air drying (40, 50, 60, 70 and 80°C), freeze drying and vacuum oven drying on rheological and textural properties of wild sage seed gum were investigated. The apparent viscosity of dried gum solutions at shear rate 60 s-1 was varied from 0.162 to 0.344 Pa.s. With increasing oven temperature from 40 to 80°C, the apparent viscosity of gums decreased from 0.271 to 0.162 (shear rate 60 s-1). The Heschel-Bulkley’s model was found the most suitable to describe the flow behavior of wild sage seed gum over the whole experiment.Drying method of mucilage has a significant effect on the change of textural characteristics of prepared gel from the dried gum and the highest value of hardness, stickiness, consistency and adhesiveness of gum texture were for freeze-dried gum, that were 78.2 g, 17.0 g, 794.8 g.s and 159.2 g.s, respectively.

Hydrocolloids (gums) are used in food science to control and improve texture, taste and also to increase stability. Most food processings cause changes in rheological and textural properties of the food. In this study, the effects of thermal treatments on color changes, rheological and textural (firmness, adhesiveness and consistency) properties of Balangu seed gum were investigated. Balangu seed gum was extracted and to evaluate the rheological properties and color, solutions with concentrations of 0.2 %(w.w) and to evaluate the textural properties, gum solutions (concentrations of 3 and 4% (w.w)) were prepared and treated under different Temperatures of 25, 50, 75, 100, 121°C, for 20 min. Viscosities of gum solutions were assessed at 25°C through Brookfield rotational viscometer and fitted by the power law, Casson and Bingham models. Fitted results indicate that Balangu seed gum possesses pseudoplastic behavior and Power law model is appropriate to evaluate it (R2=0.99). Balangu seed gum did not tolerate the high temperature of (121°C), but the texture of the prepared gels show adequate resistance against heat treatments. Hardness and consistency of Balangu seed gel (3%) following heat treatment of 121°C were recorded as 10.6gr and 32.48gr.s, respectively. In addition, with increase in temperature, the color of samples became darker (decrease in L).

The split-block experimental design with three replications was used to study the effect of subsoiling in different distances from drain axison soil salinity,and wheat yield. The measurements included soil cone index, soil bulkdensity, infiltration rate and electrical conductivity of saturated extract. Each treatment was composed of two factors. The main factors consisted of 3 different distances from drain axis including 50, 100 and 150 meters from drain axis; and the sub factors consisted of 3 cultivation methods as conventional plowing, subsoiling at soil depth of 40-45cm, and subsoiling at the soil depth of 40-45 cm + plowing. The results included that subsoiling decreased the value of soil cone index (about 25%), soil bulk density (about 4%), EC- saturated extract (about 25%), and the magnitude of other parameters such as infiltration rate and wheat yield increased by 133% and 18%, respectively.

The purpose of this research was to study and predict fuel consumption rate of tractor due to different aspect ratios of chisel plow blade and to determine a general relationship equation between aspect ratio () and fuel consumption rate. An ITM-399 (81 kW) tractor and a mounted-type chisel plow with 9 shanks were used. The 5 and 10 cm width chisel blades were used. The experiments were conducted in a clay-loam soil at 9% d.b moisture content, three levels of tillage depths (10, 15, and 20 cm), and three levels of travel speeds (3, 4, and 5 km.) in three replications. Results from F-test at 95% showed that three was no significant difference between measured values and predicted values as compared to 1:1 line plot. Normalized Root Mean Square Error (NRMSE) and Mean Bias Error (MBE) indices were used to verify the accuracy of the equation. The results validated the precision of the attained equation.