Post-harvest technologies
C. N. Onwusiribe; J. Mbanasor; P. O. Nto; M. C. Ndukwu
Abstract
Rice is a major staple food consumed worldwide, but its processing has significant environmental impacts due to water and energy consumption and greenhouse gas emissions. As a result, rice producers are adopting sustainable processing techniques to reduce negative environmental impacts and increase profitability. ...
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Rice is a major staple food consumed worldwide, but its processing has significant environmental impacts due to water and energy consumption and greenhouse gas emissions. As a result, rice producers are adopting sustainable processing techniques to reduce negative environmental impacts and increase profitability. This study analyzed the sustainability of modern and traditional paddy rice processing techniques among smallholder rice farmers in Southeast Nigeria. The data was collected from 240 rice producers using statistical approaches such as descriptive statistics, sustainability indicator (Weight Assessment Ratio Analysis), and multinomial regression analysis. The results showed that 34.7% of rice farmers used modern processing techniques while 65.3% used traditional methods. Traditional milling produced substantial carbon emissions, according to 77% of small-scale farmers, while 68% rated noise pollution as high. 80-100% of small-scale farmers using modern techniques cared about the environment and wanted to reduce their gas emissions, solid waste, energy use, and water use. The sustainability index for farmers using traditional and modern processing techniques was affected by gender experience, labor size, investment, income, cost of production, understanding of climate change, and environmental sustainability. The study recommends using renewable energy sources to increase productivity and reduce environmental effects.
Post-harvest technologies
M. Namjoo; M. Moradi; M. A. Nematollahi; H. Golbakhshi
Abstract
In this study, the air drying of cumin seeds was boosted by cold plasma pre-treatment (CPt) followed by high-power ultrasound waves (USp). To examine the impact of included effects, different CP exposure times (0, 15, and 30 s), sonication powers (0, 60, 120, and 180 W), and drying air temperatures (30, ...
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In this study, the air drying of cumin seeds was boosted by cold plasma pre-treatment (CPt) followed by high-power ultrasound waves (USp). To examine the impact of included effects, different CP exposure times (0, 15, and 30 s), sonication powers (0, 60, 120, and 180 W), and drying air temperatures (30, 35, and 40 ºC) were selected as input variables. A series of well-designed experiments were conducted to evaluate drying time, effective moisture diffusivity, and energy consumption, as well as color change and rupture force of dried seeds for each drying program. Numerical investigations can effectively bypass the challenges associated with experimental analysis. Therefore, the wavelet-based neural network (WNN), the multilayer perceptron neural network (MLPNN), and the radial-basis function neural network (RBFNN), as three well-known artificial neural networks models, were used to map the inputs and output data and the results were compared with the Multiple Quadratic Regression (MQR) analysis. According to the results, the WNN model with an average correlation coefficient of R2 > 0.92 for the train data set, and R2 > 0.83 for the test data set provided the most beneficial tool for evaluating the drying process of cumin seeds.
Post-harvest technologies
R. Khodabakhshian; R. Baghbani
Abstract
Magnetic resonance imaging (MRI) is a non-destructive technique for determining the quality of fruits which, with different protocols, shows the density and structure of hydrogen atoms in the fruit in which it is placed. This study compared MRI images of healthy and bruised apple flesh tissues, both ...
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Magnetic resonance imaging (MRI) is a non-destructive technique for determining the quality of fruits which, with different protocols, shows the density and structure of hydrogen atoms in the fruit in which it is placed. This study compared MRI images of healthy and bruised apple flesh tissues, both with and without pests, using various protocols to identify the best one. For this purpose, magnetic resonance imaging (MRI) using two protocols: T1 (Spin-lattice relaxation time) and T2 (Spin-spin relaxation time), was carried out on 200 apple fruits that were loaded during storage. The loading of fruits was performed at four levels: 150, 300, 450, and 600 N in a quasi-static manner, and then stored for periods of 25, 50, and 75 days at 4 °C. At the end of each storage period, imaging was carried out. Then, the contrast of T1 and T2 images of healthy and bruised tissue of apple fruit with and without pests using ImageJ software was determined. It was concluded that the healthy tissue of apple fruit without pests was clearer in T1 images than in T2 images. It has also been seen that the bruised area of fruits without pests in T2 images is more recognizable than in T1 images.
Post-harvest technologies
E. Barzanouni; H. Sadrnia; F. Sohbatzadeh; S. Khodavaisy
Abstract
IntroductionPenicillium Digitatum (PD) and Penicillium italicum diseases pose significant economic challenges to citrus fruit production across the globe. The primary aim of this research is to investigate the synergistic effects of low concentrations of H2O2 solution combined with transient spark discharge ...
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IntroductionPenicillium Digitatum (PD) and Penicillium italicum diseases pose significant economic challenges to citrus fruit production across the globe. The primary aim of this research is to investigate the synergistic effects of low concentrations of H2O2 solution combined with transient spark discharge plasma on the inactivation of PD. Additionally, assess the chemical and physical properties. Ultimately, this approach can be presented as an eco-friendly solution for rinsing citrus fruits on an industrial scale.Materials and MethodsThe Penicillium digitatum (PD) isolate (ATCC 24692) was obtained from the Tehran Molecular Mycology Laboratory and cultured on Sabouraud Dextrose Agar medium at pH 5.6 and 27°C for 7 days. The initial concentration of spores in the solution was determined using a UV absorption spectrophotometer, set to 0.1 at a wavelength of 420 nm, and the concentration of spores was approximately equivalent to 106 spores per milliliter (Palou et al., 2002). In this study, the plasma reactor had a point-to-plane geometry. The high-voltage needle electrode was placed above a Petri dish filled with a microbial solution combined with H2O2, while the grounded electrode was immersed in the solution. The distance between the tip of the needle electrode and the surface of the solution was 15 mm. Solutions of 0.05%, 0.1% and 0.5%v/v H2O2 (35% soluble in water) were added to the microbial solution before plasma treatment. The final volume of the solution was 5 ml and exposure times were 2.5, 5, 10, and 15 minutes. The reactor was fed with an air flow of 2 l/min. A transient spark discharge was generated, characterized by a discharge voltage of approximately 18 kV, short durations of less than 100 ns, and high current pulses exceeding 1A, with a repetition frequency ranging from 0.5 to 10 kHz. After treatment, H2O2, NO2‾, and NO3‾ as the main long-lived species in plasma-activated solution are measured. Also, physical factors such as electrical conductivity and pH were measured. Data Analysis performed using SAS 9.4 software. Results and DiscussionWith increasing plasma treatment time and H2O2 concentration, the log reduction increased across all treatments. The combination of 0.1 and 0.5% H2O2 solution with plasma resulted in complete inactivation of P. digitatum within just 15 minutes. In plasma-treated solutions, regarding chemical properties, the concentrations of H2O2, NO2‾, and NO3‾ increased linearly with the treatment time. Furthermore, the electrical conductivity increased linearly, with a notable acceleration in the treated 0.5% H2O2 solution, reaching 373µS cm-1. Additionally, pH value dropped from an initial value of 6.95, using distilled water as a control, to a low of 2.14 for plasma treated with 0.5% H2O2 after 15 min of exposure.ConclusionThe combined treatment was more effective than the isolated use of hydrogen peroxide solution. H2O2 enhances the effectiveness of plsma sterilization without requiring additional power input. Consequently, the synergistic application of atmospheric pressure plasma and H2O2 proved to be a promising method for the inactivation of PD. The findings indicate that reactive oxygen species (ROS) significantly contribute to the inactivation of PD cells, as well as the concentration of H2O2. Finally, the combination of H2O2 solution at 0.1 and 0.5% with cold plasma presents an environmentally friendly method for sanitizing citrus fruits.Acknowledgment This work was supported by the Ferdowsi University of Mashhad [Grant number 48527]. The authors greatly appreciate the technical support from Mazandaran University in Iran, particularly from the Department of Atomic and Molecular Physics.
Post-harvest technologies
A. Khalaj; E. Ahmadi; S. Mirzaei; F. Ghaemizadeh; R. Abbaszadeh
Abstract
IntroductionGrape is a major horticultural crop with a high nutritional value in the world. The optimal geographic and climatic conditions in Iran have positioned it as one of the most important regions for grape cultivation in the world. Black rot, caused by Aspergillus niger, is a highly destructive ...
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IntroductionGrape is a major horticultural crop with a high nutritional value in the world. The optimal geographic and climatic conditions in Iran have positioned it as one of the most important regions for grape cultivation in the world. Black rot, caused by Aspergillus niger, is a highly destructive fungal disease that affects the grapes by targeting wounded areas. It causes crushing of the grapes, the falling of berries, and reduces transportation and storage properties (Ponsone et al., 2011). Various methods, such as fumigating bunches with sulfur dioxide and storing them in a modified atmosphere, have been used to control fungal rot and prolong the shelf life of grapes. However, each method has its limitations. Grape fumigation with sulfur gas is harmful to human health (Duarte-Sierra et al., 2016) and the efficiency of modified atmospheric storage on rot control and maintaining the quality of grapes depends on the type of variety, storage temperature, and especially gas concentration (Himelrick, 2003).Given the lack of efficiency in traditional methods, it is imperative to introduce modern techniques that can effectively disinfect microorganisms. These advanced methods offer several advantages, including the preservation of crop quality, an increase in crop shelf life, the promotion of good health, and substantial economic benefits. A technique of this type includes using non-thermal (cold) plasma (NTP) technology to eliminate food microorganisms (Bourke et al., 2018). The effect of cold plasma at atmospheric pressure on the reduction of bacterial populations in food products such as lettuce, tomato, strawberry, and cherry tomato has been reported (Bermúdez-Aguirre et al., 2013; Pasquali et al., 2016; Ziuzina et al., 2014). Research has shown that cold plasma can effectively inactivate Aspergillus in various orchard and agricultural products (Butscher et al., 2016; Ghorashi et al., 2020; Selcuk et al., 2008). The effect of cold plasma on the quality characteristics of the product during the post-harvest period has also been investigated. Blueberries treated with cold plasma for less than 15 minutes showed remarkable results: after 10 days, the fruit exhibited reduced lipid peroxidation and darkening, with no impact on the total anthocyanin content, pH, or firmness of the product (Hu et al., 2021). In a study by Rana et al. (2020), it was found that subjecting strawberries to 15 minutes of cold plasma with packaging after 5 days of storage at 25°C had no significant impact on pH, TSS, and moisture content of the fruit.The review of the literature reveals the absence of research on fungal disease control and grape quality evaluation following the use of NTP. This study aims to investigate the efficiency of plasma treatment in reducing the infection with Aspergillus fungi, along with examining the physical, chemical, and mechanical properties of Fakhri grape.Materials and MethodsThis research was conducted as a completely randomized design in a factorial experiment at four plasma levels (0, 10, 20, and 40 s) and five storage periods (1, 2, 3, 4, and 5 weeks) with three replications at 4°C. A plasma generator was first designed and manufactured in this study. A specifically designed and fabricated plasma application probe was also developed for grape berries. The individual grape berries were then sterilized with 1% sodium hypochlorite under a laminar hood for 2 minutes. Afterward, they were rinsed three times with sterile distilled water to remove any remaining disinfectant residue from their surfaces. Sterilized berries were immersed in Aspergillus spore suspension with 105 spores.ml-1 concentration. Finally, all samples were dried on paper filters and prepared for different plasma treatment durations (0, 10, 20, and 40 s). The treated samples were stored at 4°C, and the infection percentage and microbial load were measured on a weekly basis. To assess the preservation quality, chemical parameters such as pH, TSS, and TA, physical parameters (color change and weight loss), and mechanical properties were measured every week. Additionally, thermal imaging was performed weekly.Results and DiscussionPlasma application during storage significantly reduced the infection percentage and microbial load in Aspergillus-inoculated samples. At the end of the storage period, the infection percentage and microbial load in the 40-second plasma treatment were 5% and 2.5 CFU g-1 respectively, while in the control group, the infection percentage was 100% and the microbial load was 4 CFU g-1. At the end of the storage period, the lowest pH level in the plasma was observed for 40 s plasma. This could be attributed to effective contamination control, as fungal contamination leads to alkalization of the environment. The highest amount of TSS was also observed in control and 40 s plasma. But in the 10 and 20 s plasma treatment, the process of changes was gradual and not significant. The higher TSS level of control and 40 s plasma can be due to the weight loss caused by the spread of contamination and moisture leakage caused by damage to the tissue. This decrease in moisture leads to an apparent increase in the TSS index. Research has shown that plasma primarily affects the surface characteristics of products, and when applied with the appropriate voltage and duration, it does not alter the internal chemical properties (Hu et al., 2021). Over time, weight loss increased in all treatments. This increasing trend during the storage period is higher in control and 40 s plasma compared to 10 and 20 s plasma. Therefore, the weight loss in the control can be due to the spread of contamination and aging of the product over time. However, the weight loss in the 40-second plasma treatment can be due to the destruction of the fruit tissue caused by longer duration of the plasma application.In the current research, by increasing the duration of plasma application to 40 s, a significant decrease in L*, a*, and b* indices and an overall change in the color of the product was observed. Research shows that in blueberries, inappropriate duration of plasma treatment causes the loss of wax on the fruit surface and leads to darkening of the product (Hu et al., 2021). The highest and lowest changes in temperature drop were observed in the control treatment (5°C) and 10 and 20 s plasma (3 and 3.5°C, respectively). According to research, an increase in fungal contamination leads to a decrease in humidity, increases weight loss, and subsequently a decrease in product temperature. A decline in mechanical characteristics was noted for the control and plasma treated samples during the storage period. The lowest value for indicators was observed in the 40 s plasma treatment. However, no significant difference was observed in samples treated with plasma for less than 20 seconds compared to the control group up to the middle of the storage period. According to a report by Misra et al. (2014), plasma application can reduce tissue softness. Therefore, optimizing its plasma duration and intensity is very important (Pan et al., 2021). ConclusionOur experiments aimed to investigate the effect of NTP treatment on controlling Aspergillus infections while preserving the quality properties of Fakhri grapes. The obtained results are important for two main reasons. Firstly, an innovative probe was designed for plasma applications, specifically tailored to the shape and size of individual grapes in order to thoroughly cover them with plasma. Secondly, application of plasma was carried out for the first time and yielded valuable results, indicating that this technique can control fungal infections and preserve the chemical, physical, and mechanical properties of grapes.
Post-harvest technologies
S. Sharifi; M. H. Aghkhani; A. Rohani
Abstract
IntroductionOn the field and in the paddy milling factory dryer losses have always been challenging issues in the rice industry. Different forms of losses in brown rice may occur depending on the field and factory conditions. To reduce the losses, proper management during pre-harvest, harvesting, and ...
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IntroductionOn the field and in the paddy milling factory dryer losses have always been challenging issues in the rice industry. Different forms of losses in brown rice may occur depending on the field and factory conditions. To reduce the losses, proper management during pre-harvest, harvesting, and post-harvest operations is essential. In this study, different on-field drying and tempering methods were investigated to detect different forms of brown rice losses.Materials and MethodsThe present study was conducted on the most common Hashemi paddy variety during the 2019-2020 season in Talesh, Rezvanshahr, and Masal cities in the Guilan province, Iran with 0.2 hectares and 5 paddy milling factory dryers. On the fields, the method and date of tillage, irrigation, and transplanting used in all experimental units were the same. Moreover, the same amount of fertilizer and similar spraying methods were used across all experiments. For the pre-drying process on the fields, the following three pre-drying methods were applied on the harvest day: A1) The paddies were spread on the cut stems for insolating, A2) The paddies were stacked and stored after being placed on the cut stems for 5h, and A3) The paddies were covered with plastic wrap and stored after 5h of insolating. The first method (A1) is the most common in the area and was chosen as the control treatment. For the second step of the process, the time interval between the on-field pre-drying and threshing was considered: B1) 14 to 19h post-harvest; B2) 20 to 24h post-harvest, and B3) 25 to 29h post-harvest. Afterward, methods A1 to A3 were combined with methods B1 to B3 and feed into an axial flow-thresher at 10 kg min-1, 550 rpm PTO, and two levels of moisture content at 19 and 26 percent (% w.b). The third process was two-stage or three-stage tempering for 10 or 15 hours resulting in four levels (C1 to C4) and was done in the conventional batch type dryer under temperatures of 40 and 50 ˚C and airspeeds of 0.5 and 0.8 m s-1 in paddy milling factories. At the end of each process, a 100g sample was oven-dried for 48h and a microscope achromatic objective 40x was used to detect incomplete horizontal or vertical cracks, tortoise pattern cracks, and immature and chalky grains. The equilibrium moisture content was determined to be 7.3 percent. Losses properties were analyzed using a completely randomized factorial design with a randomized block followed by Tukey's HSD test at the 5% probability and comparisons among the three replications were made.Results and DiscussionResults demonstrated that the stack and plastic drying methods significantly increased the percentage of losses. In the plastic drying method, the percentage of chalky grains and tortoise pattern cracks was higher than other forms of loss. In the first process, irrespective of the pre-drying method, the losses were reduced at a lower level of moisture content. At the end of the first stage, losses in the spreading method were significantly lower at 19% moisture content. Threshing the plastic-wrapped paddies after 14 to 19 hours at 19% moisture content resulted in the maximum threshing loss of 8.446% and over half of the grains were chalky or had tortoise pattern cracks. The threshing loss was halved (4.443%) for paddies threshed 25 to 29h after spreading at a moisture content of 26%. The mean of losses in the second step of the process were 7.229, 5.585, and 5.156% for the time interval between the on-field pre-drying and threshing of 14 to 19h, 20 to 24h, and 25 to 29h, respectively. In the last step of the process in paddy milling factory dryers, there was no significant difference in the minimum percent of losses between 10 and 15 hours of three-stage tempering at 40 °C and with 0.5 m s-1 airspeed. Furthermore, maximum total losses with the most incomplete horizontal and vertical cracks occurred in the two-stage 10h tempering at 50 °C and with 0.5 and 0.8 m s-1 airspeed.ConclusionFood security has always been a critical matter in developing countries. Furthermore, identifying the source of losses in the fields and the factories is one way to reduce losses and achieve food security. Stacking or wrapping the paddies in plastic after pre-drying on the fields for 5h is not recommended in terms of its effect on increasing the percentage of brown rice losses. Additionally, due to the importance of factory dryer scheduling in the management of the losses, it is recommended to use a three-stage 10h tempering at 40 °C and with 0.5 m s-1 airspeed.
Post-harvest technologies
V. Kahrizi; E. Ahmadi; A. R. Shoshtari
Abstract
IntroductionThe growing consumer demand for high-quality products has led to the development of new technologies for assessing the quality of agricultural products. Iran is the 9th largest orange producer in the world. Every year, large quantities of agricultural products lose their optimal quality due ...
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IntroductionThe growing consumer demand for high-quality products has led to the development of new technologies for assessing the quality of agricultural products. Iran is the 9th largest orange producer in the world. Every year, large quantities of agricultural products lose their optimal quality due to mechanical and physical damage during various operations such as harvesting, packaging, transportation, sorting, processing, and storage. This study is performed to identify the natural frequencies and vibration modes of the Thomson orange fruit using finite element modal analysis by ANSYS software. In addition, physical properties including mass, volume, density, and principal dimensions were measured, and mechanical properties were determined using Instron Texture Profile Analysis. The dynamic behavior of the orange fruit was simulated using the pendulum impact test. Afterward, the obtained impact was applied to the orange fruit by force gauge and three-axis accelerometer sensors in both polar and equatorial directions. The three-dimensional geometric model of the orange fruit was drawn in the ANSYS software. After meshing and applying the boundary conditions, the first 20 modes and corresponding natural frequencies were obtained. Since the objective of this study was to identify the natural frequencies of the orange fruit, it was considered to have free movement and rotation in space. The results showed that the natural frequencies of orange fruit are in the range of 0 to 248.41 Hz. Knowledge of the texture characteristics and dynamic behavior of horticultural products is essential for the design and development of agricultural machinery. Furthermore, the design and development of agricultural machinery are directly related to the biological properties of agricultural products.Materials and MethodsThe Thomson orange variety was used in the present study. The oranges used for the experiments were harvested from the Citrus and Subtropical Fruits Research Institute in Ramsar, Iran, located at coordinates 50° 40′ E and 36° 52′ N. The oranges were subsequently divided into two groups: large (average diameter 82 mm) and small (average diameter 66 mm). Conducting the finite element analysis requires knowledge of the physical and mechanical properties of the flesh and skin of the orange fruit. The physical and mechanical properties of the tested samples include geometric dimensions, modulus of elasticity, Poisson’s ratio, and density. In the present study, the dynamic behavior of the orange fruit under dynamic loads was investigated by performing an impact test using a pendulum. The orange fruit was hung from the ceiling using a thin thread to perform experimental tests and extract the modal parameters. The orange samples were subjected to impact at three angles: 7° (below the yield point), 10° (at the dynamic yield point), and 20° (above the dynamic yield point).Results and DiscussionThe comparison of the experimental (laboratory) natural frequencies and simulation validates the simulation results. The experimental natural frequencies of the first, second, and third modes in the large-group oranges are 125.4, 146.9, and 180.4 Hz, respectively. Additionally, the simulation (modal) frequencies are 133.80, 146.16, and 196.66 Hz for the first three modes, respectively. The lowest and the highest differences were observed in the second (0.5%) and third (9.01%) modes, respectively. In the small-group oranges, the first, second, and third modes have experimental natural frequencies of 152.2, 188.8, and 242.2 Hz, respectively, and simulation frequencies are 167.79, 187.50, and 248.30 Hz. The second and first modes exhibited the smallest and largest disparities between experimental and simulated natural frequencies, respectively, at 0.68% and 10.24%.ConclusionWhile there are certain limitations, it is undeniable that Computer Aided Engineering (CAE) applications are advantageous for predicting the natural frequencies and vibration modes of spherical fruits such as oranges. Utilizing the obtained frequencies, especially the resonance frequency and the vibrational mode shape, enables us to avoid the resonance frequency in the actual transportation of oranges. This is possible through the implementation of suitable packaging and transportation methods, thereby mitigating the deterioration of fruit quality and ensuring an accurate prediction of its shelf life.
Post-harvest technologies
M. Pourbagher; R. Pourbagher; M. H. Abbaspour-Fard
Abstract
Today, almost half of the total human food, especially in Asia, is directly supplied from grains, and nearly 70% of the cultivated area of the world, which is one billion hectares, is used for growing grains. Therefore, non-destructive methods must be found and developed to increase seed quality in agriculture ...
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Today, almost half of the total human food, especially in Asia, is directly supplied from grains, and nearly 70% of the cultivated area of the world, which is one billion hectares, is used for growing grains. Therefore, non-destructive methods must be found and developed to increase seed quality in agriculture and industry. Cold plasma is a novel and efficient method that can be used in the agricultural and food sectors for the inactivation of surface microorganisms and the excitation of seeds. This review presents a summary of the effectiveness of cold plasma treatment on the characteristics of four important cereal plants: wheat, rice, corn, and barley. The focus is on the effects of this treatment on seed germination, surface property changes, water uptake of seeds, growth parameters of root, shoot, and seedling length, biomass parameters, and metabolic activities. By examining the research conducted by the researchers, it can be seen that the cereal seeds treated with cold plasma had better germination power, water absorption, shoot length, growth efficiency, shoot and root weight, and metabolic activity. This review can provide insight into the promising trends in utilizing plasma as a method to decrease the prevalence of harmful plant diseases transmitted through seeds and reduce the dormancy of hard seeds.
Post-harvest technologies
J. Abdi; A. Golmohammadi; Gh. Shahgholi; A. Rezvanivand fanaei
Abstract
IntroductionPeanut (Arachis hypogaea L.) is an annual plant of the legume genus that is cultivated in 109 countries due to its high-quality oil and seed protein. In Iran, this crop is cultivated on an area of 3000 hectares, with an average yield of 4 tons per hectare. Threshing performance significantly ...
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IntroductionPeanut (Arachis hypogaea L.) is an annual plant of the legume genus that is cultivated in 109 countries due to its high-quality oil and seed protein. In Iran, this crop is cultivated on an area of 3000 hectares, with an average yield of 4 tons per hectare. Threshing performance significantly affects seed loss and physical damage, including cracking and crushing of seeds during harvest. Therefore, over the last century, extensive research has been conducted on different types of threshing methods, as well as the design and development of various threshing machines.Research on seed crops such as cereals and seeds suggest that factors such as the rotational speed of the thresher, threshing-concave distance, feeding rate, and shape of threshing teeth play a crucial role in determining the threshing efficiency and quality of the threshed seeds. Although limited research has been conducted on peanut threshing, there are currently no combine-machines available for this crop on global markets. Therefore, this study aims to investigate several working parameters of an experimental peanut thresher, including the effect of sieve angle, sieve range of movement, and suction speed on the separation unit.Materials and MethodsThe relevant experiments were conducted in the Parsabad Moghan region of Ardabil province (latitude 39.65 North, longitude 47.91 East). To conduct the experiments and separate the seeds from the pods, we used a peanut threshing machine cultivar Nc2, which is commonly cultivated under agricultural conditions in Ardabil and Gilan Agricultural Research Centers.To achieve the aims of this research, we investigated several effective parameters in the performance of the machine, including sieve angle, sieve movement range, and fan suction speed, to obtain the best settings for maximum threshing performance and separation efficiency. It is worth noting that the average seed weight per kilogram of peanut plant was between 300-400 grams, and the moisture content of the seeds in the tested cultivar was 45%. Before using the machine, workers must first dig up the plants and place them on the ground in a coupe, after which another worker must feed the plants into the machine through the feeder.Results and DiscussionThe study found that changes in sieve angle, sieve movement range, and suction speed significantly affect the separation efficiency and peanut loss rate at a 1% significance level. Increasing the sieving angle leads to a higher speed of material movement on the sieve, which results in insufficient time for separating straw from the seed. Similarly, increasing the sieve movement range causes a rapid decrease in cleaning efficiency. To achieve better straw-seed separation, it is necessary to apply impact shocks to the products located on the sieve within a short period. However, as the range of movement increases, the time interval between impact shocks also increases, which disrupts the straw's separation from the seed.The study found that increasing the sieve range and suction speed leads to a higher rate of peanut loss. This is due to the fact that when the suction speed and sieve movement range are increased, the product spends less time on the sieve, which results in insufficient time for proper separation. Additionally, high speed may exceed the limit of peanut seed and cause it to move out of the machine with the straw. Increasing the sieve movement range leads to a more uniform movement of straw and seed on the sieve; however, achieving better separation of straw from the sieve requires dynamic shocks and sudden acceleration, which decreases as the sieve movement range increases. The optimal farm capacity and material capacity were achieved with a 5-degree slope at 0.55 hectares per hour and 509 kilograms per hectare, respectively, using a sieve range of 3.5 centimeters and a fan suction speed of 8 meters per second.ConclusionThe study concluded that the sieve movement range has the most significant impact on cleaning efficiency, while the sieve angle has the least effect. Similarly, the sieve movement range has the most significant influence on the rate of peanut loss, while the sieve angle has the least effect.
Post-harvest technologies
H. Rezaei; M. Sadeghi
Abstract
IntroductionDue to the disadvantages of using chemical materials as pretreatment before grape drying, the application of non-chemical methods that not only take the environmental issues into account but also increase the drying rate and improve the quality of the produced raisins is vitally important. ...
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IntroductionDue to the disadvantages of using chemical materials as pretreatment before grape drying, the application of non-chemical methods that not only take the environmental issues into account but also increase the drying rate and improve the quality of the produced raisins is vitally important. The high-humidity hot air impingement blanching (HHAIB) is one of the non-chemical methods that can be used as a suitable alternative for chemical pretreatment in grape drying. In this research, the design, construction, and evaluation of a high-humidity hot air impingement blanching system are discussed in terms of the drying kinetics of white seedless grapes. The results are compared against the control and chemical pretreatment.Materials and MethodsHigh-humidity hot air impingement blanching (HHAIB) systemThe HHAIB system is composed of the steam generator, steam transfer pipes, side channel pump, closing and opening valves, air recycling channel, electric air heater, hot-humid air transfer channel, pretreatment chamber, hot-humid air distribution chamber, nozzles, temperature and humidity sensors and controllers. The performance of the system depends on the humid air temperature, the output fluid velocity from the nozzle, the distance of the nozzles from the product surface, as well as the diameter and arrangement of the nozzles. In order to achieve optimal design of the nozzle array, the relationships existed for the heat transfer coefficient, air mass flow, and blowing power were considered.Application of the HHAIB pretreatment and evaluation of its effect on the grape drying processExperiments were conducted to investigate the effect of temperature and duration of HHAIB pretreatment on the kinetics of grape drying. A two-factor completely randomized factorial design with three replications was used to analyze the data.According to the studies, the air at temperatures of 90, 100, and 110°C, a velocity of 10 m s-1, and relative humidity in the range of 40-45% was applied to the product. Pretreatment durations of 30, 60, 90, 120, and 150 s were also considered. Experiments were conducted with three replicates and control treatment and acid pretreatment were used to compare the drying process. Due to the high quality of shade-dried raisins, this method was used to study the process.The effect of the pretreatment duration on the drying kinetics of white seedless grapes was assessed by observing variations in moisture ratio and drying rate over time, as well as determining the effective diffusivity of water.For the color evaluation of the produced raisins, chroma (C), hue angle H°, and total color difference (ΔE) parameters were calculated after measuring L*, a*, and b* values.Results and DiscussionThe comparison of the drying process among the control, chemical, and HHAIB showed the positive efficacy of HHAIB on the drying rate of grapes. Compared to fresh grapes, the increase in drying rate under the influence of HHAIB varied from 8% for a duration of 30 s at 90°C to 68% for a duration of 150 s at 110°C. The values of the diffusion coefficient of grapes for the HHAIB pretreatment at temperatures of 90, 100, and 110°C and durations of 30, 60, 90, 120, and 150 s, as well as for the control and chemical pretreatments were determined. The values of the coefficient changed from 2.28×10-10 m2 s-1 for 30 s of applying pretreatment at 90°C to 3.53×10-10 m2 s-1 for 150 s of applying the pretreatment at 110°C. The highest value of this coefficient (7.46×10-10 m2 s-1) was associated with the chemical pretreatment. The value of the diffusion coefficient increased with increasing temperature and duration of the HHAIB pretreatment. In general, this increase in the drying rate and the diffusion coefficient can be attributed to the effect of the HHAIB pretreatment on the texture and destruction of the cell wall, as well as the microcracks created on the skin of the grapes. Moreover, the findings reveal that, in comparison with the hot air temperature, the duration of the HHAIB pretreatment was more effective in enhancing the drying rate. Additionally, based on the color analysis, a temperature of 110°C and a duration range of 90-150 s were achieved as suitable conditions for applying pretreatment.ConclusionThe HHAIB pretreatment, which combines the benefits of hot air blanching with jet technology, affects the texture and skin of grapes, accelerates the drying process, and increases the quality of the produced raisins. However, the correct application of this pretreatment depends on the proper design of the system and appropriate conditions, including duration, temperature, and relative humidity. The results of drying kinetics showed that the drying rate increased with an increase in the temperature and duration of the pretreatment. The findings indicate that the HHAIB pretreatment could improve the color indices of the raisins, resulting in an increase in the drying rate and acceptable quality of the final product. This provides a basis for the use of HHAIB on larger and industrial scales.
Post-harvest technologies
Z. Zangene Wandi; H. Javadikia; N. Aghili Nategh; L. Naderloo
Abstract
IntroductionThe use of corn oil in diets is due to its positive effects on cardiovascular and immune systems. Corn oil is composed of 99% triacylglycerol, with 59% unsaturated fatty acids and 13% saturated fatty acids. Of the unsaturated fatty acids, 24% contain a double bond. Because of this composition, ...
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IntroductionThe use of corn oil in diets is due to its positive effects on cardiovascular and immune systems. Corn oil is composed of 99% triacylglycerol, with 59% unsaturated fatty acids and 13% saturated fatty acids. Of the unsaturated fatty acids, 24% contain a double bond. Because of this composition, corn oil can be a good alternative to other oils high in saturated fatty acids, as it reduces blood cholesterol levels.This study employed an electrical nasal system to detect the amount of palm oil present in corn oil. The properties extracted from the signals obtained by the device were processed using principal component analysis, artificial neural networks, infusion, and response surface methods. The results were then compared to find the best method for detecting palm oil levels in corn oil.Materials and Methods The required palm oil was obtained from the Nazgol Oil Agro-industrial Plant, while the corn oil was obtained from natural lubrication centers. To prepare samples with different percentages of palm oil, 75 grams of palm oil and corn oil with the specified percentages were mixed and stored in special containers.In the electrical nose system, ten metal oxide semiconductor sensors (MOS) were used to collect output data. Pre-processing operations were performed on this data using RSM, ANFIS, PCA, and ANN methods to estimate the percentage of palm oil in corn oil. The Unscrambler V.9 software, Design Expert 8.07.1, and MATLAB R2013a were used to analyze the results.Results and DiscussionBased on the Score plot, PC-1 and PC-2 explain 53% and 25%, respectively, describing the variance between samples for a total of 78 data points. The analysis indicates that sensors 7 and 8 have minimal impact on the detection process and can be removed from the sensor array. When reducing the cost of the olfactory system's sensor array, sensor 6 plays a more significant role than other sensors in detecting corn oil with palm composition.According to the loading diagram of palm percentage in corn oil, the MQ6 sensor had the least effect in classifying different percentages of palm in corn oil and pattern identification. Out of all functional parameters (accuracy, sensitivity, and specificity), the RSM method is deemed more appropriate for determining the percentage of palm in corn oil.Regarding the separation of corn oil and palm oil by ANFIS, RSM, and ANN, the results in Table 3-1 indicate that the RSM method is better suited for classifying corn and palm oil.Conclusion In this study, we used an electronic multi-sensor system based on metal oxide sensors to analyze various aromatic compounds in different oil and palm samples and to detect the presence of palm. The system provided comparable information for classifying different samples of palm oils. Using PCA, ANN, ANFIS, and RSM methods, we evaluated the system's performance in differentiating and classifying various oil and palm samples.The results obtained from the loading diagrams for the detection of palm in corn oil indicated that the MQ6 sensor had the least impact on the detection process. Therefore, this sensor can be removed from the sensor array.Additionally, our analysis showed that using the RSM method is more effective in detecting different percentages of palm in corn oil. Overall, our study demonstrates the efficacy of the electronic multi-sensor system in analyzing different oil and palm samples and detecting the presence of palm.
Post-harvest technologies
F. Osloob; M. Moradi; M. Niakousari
Abstract
Accurate investigation of kinetics and development of high-precision seed drying models will help better studying the drying process by identifying effective parameters. Present study investigates the application of cold plasma (CP), as a pretreatment process, in air drying of canola seeds. This may ...
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Accurate investigation of kinetics and development of high-precision seed drying models will help better studying the drying process by identifying effective parameters. Present study investigates the application of cold plasma (CP), as a pretreatment process, in air drying of canola seeds. This may bring about some complication into the drying kinetics investigation. Canola seeds with an initial moisture content of 27.5±1% (dry basis) were exposed to CP for 0, 15, 30, and 60 s prior to fluidization by air at temperatures of 40, 50 and 60 °C in a pilot scale fluidized bed heated by a solar panel. The results showed a decreasing trend in drying time from 40 to 60 oC. The shortest drying time corresponds to samples dried at 60 oC with no CP pretreatment. The longest period however occurred for samples dried at 40 oC with 60 s of CP pretreatment. The greatest effect of CP on reducing the drying time was observed at temperatures of 40 and 50 °C at the CP exposure time of 15 and 60 s, respectively. A reasonably accurate study of drying kinetics was accomplished using the superposition method. Accordingly, using experimental data, curves correspond to different drying conditions were plotted and in two steps these were shifted to a reference curve to acquire a final drying curve. The curve then was fitted to a second-order equation, and was validated using the experimental data. The correlation coefficients, mean square error and mean absolute error were 0.99, 0.03, and 0.023, respectively.
Post-harvest technologies
H. Masoudi
Abstract
In this study, an electronic system was built to determine the mass and volume of orange fruits from their dimensions using ultrasonic sensors. The system hardware parts include a metal box, three ultrasonic sensors, a load-cell sensor, an Arduino board, a memory card module, a voltage converter, a keypad, ...
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In this study, an electronic system was built to determine the mass and volume of orange fruits from their dimensions using ultrasonic sensors. The system hardware parts include a metal box, three ultrasonic sensors, a load-cell sensor, an Arduino board, a memory card module, a voltage converter, a keypad, a display and a power adapter. A computer program was written to obtain data from ultrasonic sensors and determine the mass and volume of fruits using regression relationships in Arduino software. 100 samples of orange fruits (Dezful local variety) were picked randomly from a garden and various measurements were done to determine the main physical properties of fruits including three dimensions, mass (M), and volume (V). The system output values for mass and volume of orange fruits with their actual values had no significant difference at 1% probability level. The root mean square error (RMSE) in determining the oranges mass and volume by the system were 9.02 g and 10.90 cm3, respectively. In general, the proposed system performance was acceptable and it can be used for determining the mass and volume of orange fruits.
Post-harvest technologies
A. Heydarian; E. Ahmadi; F. Dashti; A. Normohammadi
Abstract
IntroductionThe quick deterioration of fruit and vegetables has led researchers to find a solution to increase the shelf life. Foodstuff packaging is a vital technology to maintain freshness, prevent deterioration, and physiological and mechanical damages, and increase the shelf life of fresh products. ...
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IntroductionThe quick deterioration of fruit and vegetables has led researchers to find a solution to increase the shelf life. Foodstuff packaging is a vital technology to maintain freshness, prevent deterioration, and physiological and mechanical damages, and increase the shelf life of fresh products. Employing various post-harvest technologies prevent light, heat, and humidity transmission and control the microorganism activity, thereby reducing the cost and maintaining the quality of fresh and processed products during storage. Fresh okra has a shelf life of 10 days and is stored at 1-10°C due to high respiration rate and moisture loss. Today, the use of nanotechnology in the packaging industry is developed and expanded. The aim of the packaging is to increase the shelf life and prevent bacterial and shipping damages, as well as control the humidity and gases transmission, thereby reducing food spoilage. Modified atmospheric packaging (MAP) is one of the famous methods for increasing the shelf life of fresh products in which the aging process is reduced by increasing CO2 and decreasing. Decreasing the respiration rate, producing ethylene, and metabolic reactions in the modified atmosphere lead to a reduction in product deterioration. The use of coatings and edible films is being increased in order to maintain sensitive features like flavors, fragrances, and the appearance of different products and increase the shelf time of fruits and vegetables. Chitosan edible coating is a non-fragrance and non-flavor polysaccharide with a high molecular weight that is widely used because of its antifungal, biological, and biochemical properties. Chitosan is a natural polymer obtained from chitin, which is abundantly found in crustacean shells. The aim of the present study is to evaluate the effect of packaging films and chitosan coating under the modified atmosphere storage condition on qualitative and quantitative parameters of okra during storage.Materials and MethodsThe process of present research was performed in the Laboratory of Mechanical Properties and Rheology of the Biosystem Engineering Department, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, in 2016. Okra cv. Kano Dwarf was selected due to its short post-harvest life and provided by farms in Kermanshah Province. Okras were handpicked and they were free of any spots, contamination, or decay, with the almost same size and shape, without any mechanical and microbial damage. The treatments of the present study were chitosan covering, modified atmosphere by a gas mixture of 5% O2 + 10 CO2 + 85% N2, three types of packaging films including silicone nano-emulsion (Nano Bespar Aytak Co.), nano-polyethylene, and light polyethylene (LFO200), as well as two temperature levels of 1 ± 4°C (refrigerator) and 1 ± 25°C (room temperature). The influence of modified atmospheric treatments, chitosan coatings, and packaging films at two storage temperatures on chemical factors (pH and TSS) and mechanical properties including shear stress (TB), shear force (FB), shear modulus (GK) were evaluated at the end of 12 days of storage in a completely randomized design with a factorial experiment in three replications on Okra.Results and DiscussionAmong the films used, silicon nano emulsion film and chitosan coating were more able to maintain TSS. The pH value decreased due to the control of respiratory rate and corruption under modified atmospheric conditions. The mechanical properties of the samples showed that the shear stress changes of the coated sample were significantly less than the untreated ones compared to the beginning of the maintenance period. The sample stored at 4°C had less shear force during the storage period than similar specimens at 25°C. The modified atmosphere caused the shear modulus to decrease with increasing storage time compared to the beginning of the storage period.ConclusionThe results of the present research revealed that silicon nano-emulsion film has a higher capability in preserving the qualitative and quantitative properties of okra compared to other studied films. Between the two studied temperatures, 4°C storage temperature had better performance in preserving qualitative and quantitative properties of the okra compared to 25°C. The controlled atmosphere increases okra's shelf life due to reduced respiration rate. In general, maintenance of the products in a modified atmosphere package preserves the quality of the products and extends their shelf life.
Post-harvest technologies
A. Ramezani Boukat; H. Navid; M. J. Musevi Niya; S. Ranjbar
Abstract
Introduction Transportation of fresh fruit and vegetables is complicated because it can be affected by various factors. Truck vibration is one of the most prevalent causes of mechanical damage to fresh fruit during transportation. Poor driving performance, road features, package features, truck features, ...
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Introduction Transportation of fresh fruit and vegetables is complicated because it can be affected by various factors. Truck vibration is one of the most prevalent causes of mechanical damage to fresh fruit during transportation. Poor driving performance, road features, package features, truck features, package location, and fruit features are the main factors that affect truck vibration. After the harvest, the crop's quality can be maintained and cannot be improved. Thus, the globalization of fresh produce trade needs better long-distance transportation systems to deliver high-quality products to the consumer. Fruit packaging is an essential factor in reducing the mechanical damages caused by transportation. A wide-ranging of distribution environments could affect designing packages. Accurate information about the traffic and transportation status of any region helps packaging designers to produce a more precise simulation of the existing conditions. Thus, this research was conducted to analyze the vibration levels for truck transport on highway roads using multi-sensor-based computing on packaged fruit in Iran.Materials and Methods Towards this goal, a wireless sensor network (WSN) made of three sensor nodes with tri-axial accelerometers was designed to measure the vibration levels of a truck equipped with leaf-spring suspension on highway roads. This WSN solution enabled the sensors to be easily mounted at different locations and provided real-time data monitoring. A GPS receiver and a laptop were used to determine the location of the truck, and data analysis, receptively. To analyze the vibration data a, power spectral density function (PSD) levels were applied. A PSD function shows the strength of the variations (energy) as a function of frequency. Broadly, it shows at which frequencies variations are strong and weak. The vibration levels measurement was carried out on three trucks with leaf-spring suspension. The three selected routes represent different roads type in Iran. The reason for sampling the data acquired in the long route was to obtain information from different geographical locations on the country's roads.Results and Discussion The acquired data can be used in laboratory vibration tests if it is independent of the fruit type. Because the acceleration of the truck bed, unlike the one in top rows, does not depend on the fruit type and the acceleration at the end of the truck is higher than at the front, the current study focused on the vibration at the end of the truck bed. Compared to the ASTM 4728 standard, the PSD levels of the truck on highway roads were higher from 1 to 35 Hz and lower from 35 to 200 Hz. The average RMSG values calculated for lateral, longitudinal and vertical directions of heavy trucks were 0.406, 0.236, and 0.654 G, respectively. For trucks with spring suspension, the highest PSD values occurred at frequencies below 6 Hz, and the frequency range of 3-4 Hz was determined as the dominant frequency. Comparing the average RMSG (0.654 G) found with the ones mentioned in previous studies showed that the vertical vibration levels of the truck in Iran are higher than in most countries. Apart from driving quality, these results can be explained by the type of suspension system, amount of load, and road quality.Conclusion In sum, the results can be used to simulate the truck transport conditions by programmable vibration simulators to reproduce the vibration conditions for package testing on Iran roads. The findings are highly interested in improving packaging design, reducing fruit damage, maintaining shelf life, smart transportation, and related industries. Thus, potential future works are lab simulations, optimizations of packages, and the development of a real-time vibration monitoring system.
