hamidreza ghassemzadeh

Chicory (cichorium intybus) is a perennial herbaceous plant of Asteraceae family, and resistant to cold climate and frost. Chicory root containing 70-94% inulin, based on dry weight is considered as a major source of inulin for industrial production. Inulin is a fructologosaccharide and is a substitute for fat and sugar that is not digestible, but in the colon, it is used by bifidobacteria. Some of these bacteria are used as a periosteum and are very useful for human health. Drying is one of the most important post-harvesting processes of medicinal plants, which plays a major role in the quantity and quality of its active ingredients. To prevent fresh chicory root from deterioration, it should be dried for long-term storage. The aim of this study was to investigate the effect of drying in low pressure on the quality and time of extraction of inulin from Chicory root. For this purpose, the chicory roots were first dried at 80 °C under two different oven pressure of 35000 and 75000 Pa for one hour, then the inulin was extracted using diffusion process in hot water for 70 and 150 min. For qualitative evaluation, extracted inulin was analyzed through High Performance Liquid Chromatography (HPLC) with refractive index (RI) detector. Based on results from HPLC analysis, the dried sample at 750 mbar and extraction time of 150 min had the highest amount of inulin, while the dried sample at 750 mbar and the extraction time of 70 min had the lowest amount of inulin.

Long boom sprayers as efficient and high-performance machines enable farmers to carry out crop protection within a reasonable period. Despite many pieces of research, heterogeneity in spray pattern due to boom vibration remains a major challenge. In the present research, the feasibility of adjusting spray angle through pressure variation in conjunction with spray rate control using a pulse width modulation (PWM) to accomplish desired spray pattern was investigated. Using acquired data from various technical tests, a program developed via LabVIEW software to control the spray pattern along with spray rate as a function of nozzle height. The conformity of mean operational pressures and target pressures was investigated using the Kolmogorov–Smirnov Test. A similar method was used to investigate the conformity of mean operational fan angles and target fan angles. Mean differences of operational pressures were almost insignificant in the whole range of measurement height. Therefore, it can be concluded that the height factor has no significant effect on the ability of the system to obtain the target pressure. Results also indicated that mean operational pressures are in conformity with target pressures. Distribution of the operational and target fan angles was significantly difference. Considering the existence of target pressure in the system and the inability of the system in providing the target fan angle, it is concluded that nozzle performance in creation the target fan angle was not perfect.

Bread is one of the most important food sources for consumers, especially in developing and underdeveloped countries. Large quantities of bread are wasted every year because different factors affect the number of waste products include flour quality, bread production technology, and the storage condition of the bread. Among the factors affecting the quality of the flatbread, technological factors including the source and method of heating the dough and the type of baking bed are very important. Those factors affect the quality and staleness of the bread and the amount of energy consumed per ton of the produced flatbread. All of these issues depend on how heat and mass are transferred. At present, for the baking of the flatbread, direct heat transfer of the burner (torch) to the dough is utilized in the Iranian bread industry. The use of the direct heat method in baking causes non-uniform heat distribution and non-uniform baking of the flatbread. Also, it causes the deposition of some chemical compounds such as benzopyrenes on the surface of the bread due to incomplete combustion of fuel and gases from the burning process of fossil fuels. At present, the change in the structure of bread production from traditional methods to industrial methods is one of the most important factors in the production of safe and standard bread while improving its quality. The objective of this study was to improve existing systems and developed the new flatbread industrial baking machine to increase product quality and product storability.

The design and construction of the oven were performed based on the existing machine in the bread industry. The final dimension of the bread baking machine was 250 ×250 cm, a height of 160 cm. Rotary bread baking machine with an indirect heating system was designed and heat exchangers of the machine were simulated. The uniformity of airflow velocity inside the exchangers and the distribution of heat on the dough on the baking bed were investigated. After achieving the most effective design, the exchangers were constructed and installed inside the baking machine. A rotary baking bed was constrained with cast iron with a diameter of 220 cm and a thickness of 18 mm that was able to rotate horizontally. A three-phase electric motor with a speed of 1400 rpm and a power of 1.5 kW was used for the rotation system of the bed and carousel assembly. Two heat exchangers with an optimized shape were constructed with SS310 coupled with 2 burners. Bread baking experiments with the developed machine and the existing conventional machines were conducted to evaluate the sensory and staling characteristics of the produced flatbreads from different baking machines.

The simulation results indicated that the air velocity in the center of the middle pipes of the upper exchanger with a standard deviation of 0.05 was in the range of 1.552 to 1.72 ms-1, which means an acceptable uniformity. In the lower heat, there was a relatively uniform air distribution. The experimental validation of the developed simulator indicated that there is good agreement between the measured and predicted air velocity. In the top exchanger, R2 and RMSE were 0.9 and 0.36, respectively and in the top exchanger, they were calculated to be 0.97 and 0.218, respectively. The results indicated that the sensory qualities of the bread produced with the indirect heating system in the present study as well as uniformity of baking and sensory acceptability were superior compared to the bread produced from the conventional industrial machines with direct heating systems (with a total sensory score of 5.09 vs. 4.54). Mold was also observed in a few breads, with direct heating samples, after 168 hours of storage. However, no significant changes were observed in the quality of the bread cooked by direct heating methods after 48 hours of storage, and this type of flatbread lasted more than 168 hours without mold. It should be noted that mold is one of the most important quality deterioration factors and its weight in the quality assessment of the bread is greater than the other quality evaluation factors even though it has not been included directly in the evaluation standards. If the bread becomes moldy, it will be unsafe for consumption and fully wasted. Accordingly, the flatbread produced by the indirect heat was the best choice for long-term storage purposes and the reduction of food waste. Another feature that was evaluated in the bread was the uniformity of baking of all parts of the flatbreads. One of the main problems with the industrial direct heat baking machines is the fact that the outer edges of the flatbread burn due to the inadequacy and somehow incompatibility of the exchangers with the baking space, the dimensions of the flatbread, and incorrect design of the heat exchangers. The flatbread baked with indirect heat and the newly designed exchangers was very uniform with no signs of burning in the outer edges of the bread.

In general, the results of the current study indicated that the use of the simulation tools, the design and manufacturing of the new exchangers and uniform indirect heating of the baking bed resulted in the production of higher quality bread which could be stored for a longer period of time while reducing the food waste. Also, bread prepared using the new machine was free of any contaminants such as PAHs.

 In this research, some parameters affecting walnut kernel extraction quality under impact loading were studied. The tests were carried out on the available genotypes in Iran. For this purpose, three different genotypes from walnut orchards of Azarshar city were selected and the total yield of these genotypes was collected. The universal test machine (Hounsfield) was used for the compression tests. For the impact tests, four factors were evaluated in a factorial experiment using a completely randomized design with five replications. The factors were genotype, moisture content, load direction with three levels, and compression speed (three levels), and the effect of these factors on kernel extraction quality was studied. Walnut breakage assessments and kernel extraction quality were evaluated by well-defined criteria. Generally, with increasing moisture content, the percentage of broken kernels decreased and the extraction quality grade was improved. The percentages of broken kernels increased when compression speed was increased. Generally, soaking the walnuts in water for 12 h and Y loading direction yielded the best kernel extraction quality.

In this research, some parameters affecting walnut kernel extraction quality under impact loading were studied. The tests were carried out on the available genotypes in Iran. For this purpose, three different genotypes from walnut orchards of Azarshar city were selected and the total yield of these genotypes was collected. The universal test machine (Hounsfield) was used for the compression tests. For the impact tests, four factors were evaluated in a factorial experiment using a completely randomized design with five replications. The factors were genotype, moisture content, load direction with three levels, and compression speed (three levels), and the effect of these factors on kernel extraction quality was studied. Walnut breakage assessments and kernel extraction quality were evaluated by well-defined criteria. Generally, with increasing moisture content, the percentage of broken kernels decreased and the extraction quality grade was improved. The percentages of broken kernels increased when compression speed was increased. Generally, soaking the walnuts in water for 12 h and Y loading direction yielded the best kernel extraction quality.

One of the most time-consuming and difficult stages of crop production is the harvesting stage, that almost more product losses occur at this stage. Adjustments are very important in increasing the efficiency of grain combine harvesters and subsequently decreasing product loss. However, good adjustments require the identification of the components of the harvester, quantifying the losses in these components. In this research, a model has been developed to measure the rear losses of combine harvester (total threshing and separation losses) based on machine parameters. In this research, the effects of different levels of forward speed (3, 4 and 5 km/h), cylinder rotating speed (1100, 1200 and 1300 rpm) and fan speed (600, 700 and 800 rpm) on rear losses of combine harvester in three replications were investigated. A factorial experiment based on a randomized complete block design generally results of ANOVA showed that the travel speed, cylinder rotating speed and fan speed had significant effect on rear loss. Multivariate linear regression was used to make model and determine the relationship between rear loss and investigated parameters. The results of the regression model analysis showed that there was a good fitting between the rear loss and the parameters at the probability level of 1 or 5%. In other words, this model can be used for prediction of combine harvester rear loss under different operational conditions. The coefficient determination of model was obtained 0.85, which shows that a significant part of the rear loss of combine harvester is justified by the three parameters examined in this study.

Previous studies have indicated the positive impact of dietary supplementation of arginine on meat quality and growth, though there is no report regarding the effect of in ovo injection of arginine on meat quality. So, the aim of this study was to evaluate the effect of in ovo injection of different levels of L-arginine on hatchability, growth performance, and meat quality of Ross 308 broiler chickens. In this research, 300 fertile eggs were used in a completely randomized design with three experimental treatments (levels of 0.5 and 1% of L- arginine and total control). Experimental groups included: 1) in ovo injection of 0.5% L-arginine, 2- in ovo injection of 1% L-arginine, 3) total control group {collected control 1 (injection of distilled water) and control 2 (no injection)}, which were injected on d 14 of incubation. After hatching, broiler chicks of arginine treatments and total control group were divided each into four equal groups and placed randomly into four cages (replicates of the experiment). The rearing period continued from hatching to d 24. In order to investigate the quality of meat, on day 24, three chicks from each replicate (12 chicks per each treatment) were weighed, slaughtered and their breast muscles were used for meat quality evaluation. Based on the results, in ovo injection of different levels of L- arginine did not significantly affect 1, 10 and 24 day-old birds’ weight, daily weight gain, feed intake, feed conversion ratio, and relative weight of scalped carcass and breast muscle (P >0.05). Although, meat pH, meat fat and Ash content, and meat color indexes (a*, b*, L*, H) were not affected by L- arginine in ovo injection treatments (P>0.05), meat water loss, ΔD, and C indexes were significantly affected by experimental treatments (P˂0.05). Based on the overall results of this study, in ovo injection with different levels of L- arginine could not have a significantly noticeable effect on growth performance, meat production and/or meat quality of 24 day- old broiler chickens.

Increase of municipal waste which mainly consists of domestic waste and, in other words, environmentaly biodegradable materilas, pose serious challenges to the selection of efficient disposal methods every year. Lack of comprehensive data set as well as uncertainty in some cases make decision making on waste disposal method selection more complicated and requires a more efficient waste treatment system.
In this study, the hierarchical analysis process was used to assess and prioritize waste disposal methods. Considered methods were: composting, incineration, segregation and sanitary landfilling of urban waste. The criteria for evaluation of options included: waste synthesis, environmental issues and costs.
According to the results obtained from analysis of collected information, environmental issues with the relative value of 0.778 were the most important criterion to be considered. Finally, the waste segregation and sanitary landfilling with the absolute value of 0.444 proved to be the best option. Compost production and incineration methods were ranked next, respectively. The inconsistency rate for all comparisons was 0.1 which is considered acceptable.
Considering the small difference between the final values obtained for sanitary landfill and compost production methods, both should be studied more closely. The studies on waste synthesis in different parts of the country confirm the findings of this study.