Effect of curing conditions and harvesting stage of maturity on Ethiopian onion bulb drying properties

The study was conducted to investigate the impact of curing conditions and harvesting stageson the drying quality of onion bulbs. The onion bulbs (Bombay Red cultivar) were harvested at three harvesting stages (early, optimum, and late maturity) and cured at three different temperatures (30, 40 and 50 oC) and relative humidity (30, 50 and 70%). The results revealed that curing temperature, RH, and maturity stage had significant effects on all measuredattributesexcept total soluble solids

Comparison of quality characteristics of fresh and of dried strawberries

The strawberry is a very importantberries fruit. It can be used fresh or for production of different products, available for consumption during the whole year. The aim of this research was to compare the quality changes of fresh and dried strawberries. For drying were used the strawberries varieties: elsanta, humi grande and mesecharka, from Skopje region. Before drying were applied the following treatments: V0 – not treated, V1 - with vitamin C, V2 - with sugar solution. The drying was performed in Armenian solar dryer. During research were examined the chemical components of fresh and dried strawberries: total dry matter, sugars, total acids, proteins, vitamin C and mineral matter.On solar dried strawberry were performed microbiological analysis according to appropriate regulations. According to this research, the Armenian Solar Dryer is very good in economical and ecological aspect as well as quality properties

Study Of Heat-Physical Processes In Solar Dryers

 This article raises the problem of studying the thermal and physical processes that take place in solar fruit dryers. Technological processes related to the quality of dried fruits in dryers were studied

Solar Powered Fruit Dryer for Market Gardeners in Shelek, Kazakhstan

ME450 Capstone Design and Manufacturing Experience: Fall 2015The people of Shelek, Kazakhstan use their backyard gardens as a source of additional income in order to help combat the wealth disparities throughout the city. In the summer harvest seasons, there is an overabundance of fruit that needs to be sustained for potential sales. In order to preserve the surplus of fruit, the people of Shelek strongly desire a fruit dryer. Many residents of Shelek do not have access to electricity as it is too expensive to have electrical wiring connected to their homes from the existing poles. Therefore, a passive solar fruit dryer would be necessary to help the residents of Shelek preserve their surplus of fruit. There have been many successful attempts at constructing a solar fruit dryer, however, the defining challenge is the cost and manufacturability of the product. Many designs include materials that may not be readily available or too expensive in Shelek. Through the process of benchmarking, concept generation, prototype builds, engineering analysis, risk assessment, and verification testing, we have created a successful to-scale indirect solar fruit dryer over the course of four months. This project will continue to be improved through the University of Michigan’s BlueLab student design team. The team will continue working with the to-scale prototype to test in summer conditions, install additional features such as adjustability of ventilation and initial airflow, and potentially look at natural (and safe) materials to absorb moisture in the chamber such as coal or silica gels.http://deepblue.lib.umich.edu/bitstream/2027.42/117354/1/ME450-F15-Project12-FinalReport.pd

Physico-chemical and microbiological analysis of Fuyu persimmon dehydrated in solar dryer / Análises físico-químicas e microbiológicas de caqui Fuyu desidratado em secador solar

The increased production of persimmon in recent decades has not been accompanied by market demand, considering the high perishability of the fruit, it is essential to study conservation techniques that seek to extend the shelf-life, ensure quality and food safety and add value to the fruit benefited. Given the above, this study aimed to analyze the bromatological and microbiological characteristics in Fuyu persimmon (Diospyros kaki cv. Fuyu) dehydrated by natural drying in a solar dryer. According to the experimental conditions and based on the results, it was verified that the natural drying process in solar dryer in fruits of Fuyu persimmon was efficient, evidenced by the physicochemical parameters and microbiological standards that are in accordance with the established legislation. 

The cherry drying as a complementary conservation process to conservation in cold

Cherry is greatly enjoyed by consumers because of its excellent organoleptic and nutritional characteristics. This fruit is of the non-climacteric type, which forces its immediate commercialization after harvesting or else it should be properly conserved in cold. Every year there is a big waste of fresh cherry because he could not be marketed before deteriorating both in cooling chambers, or even in their own cherry trees due to a rapid ripening. In this project, the process of making cherry raisins is studied so as to provide increased use of fresh cherry. For that purpose, three different processes of dehydration of fresh cherry have been used, such as freeze drying, hot-air drying and solar drying. Three types of samples of pitted cherries were also used - natural cherry, blanching cherry and bleaching cherry with osmotic solution of fructose. In order to assess the performance of the dryers the curves of drying rate were determined and to assess the quality of the cherry raisins, fundamental parameters were determined, namely moisture content, water activity (aw), texture, total soluble solids and total acidity. The results show that the drying rate of cherry samples is similar in the lyophilizer and hot air dryer, and yet faster in the latter. The dryer with lower rate drying and hence with higher drying time was the solar dryer. The characteristics of the cherry raisins depend on the type of dryer used and the pre-treatment used. The blanching pretreatment proved to be the most suitable. Regarding dryers, the solar dryer provided good quality cherry raisins, showing great potential at industrial level with the advantage of not consuming energy.info:eu-repo/semantics/publishedVersio

Review of solar dryers for agricultural products in Asia and Africa : An innovation landscape approach

Solar drying is one of the most efficient and cost-effective, renewable, and sustainable technologies to conserve agricultural products in Asian and sub-Saharan African (SSA) countries. This review paper presents the different types of solar dryers that are widely used in Africa and Asia. In addition, the pre-eminent effects of their use on product quality, as well as their economic, environmental, and social impacts, are highlighted. Since financial, external, and structural factors play a key role in the adoption and scaling of solar dryers, this paper also discusses the impact of these factors on the effectiveness of solar drying technologies in selected Asian and SSA countries.</p

Development of a hybrid mixed-mode solar dryer for product drying

Gefördert durch den Publikationsfonds der Universität Kasse

RESEARCH THERMOTECHNIC ANALYSIS OF CRADLE-CONVEYOR DRYER

In the given work, results numerical modeling for research and an estimation of thermal productivity of drying chamber combined solar-fuel drying installation which is based with cradle-conveyor, heated up by direct receipt of sunlight and an additional source of heat are presented. All calculations have been spent in cases of an “empty” condition drying chamber and “non-working” mode of infrared lamps.Into a database of the given program are entered all thermophysical and physical properties of materials and the substances used in solar dry kiln. Absorbing ability and factor of radiation of a surface of a wall solar dry kiln make chambers (case) 0.90 and 1.0 accordingly where it is made of the processed stainless steel having following properties: the density of 7900 kg/m3 , a specific thermal capacity of 500 J/(kg∙ ̊С), factor of heat conductivity of 16.3 W/(m ̊С), and as the entry condition its temperature has been chosen, equal ambient temperature. In quality translucent coverings have been used polycarbonate sheets having following properties: density of 1200.00 kg/m3 , a specific thermal capacity of 1200 J/(kg∙ ̊С), it has been specified that in them heat conductivity is homogeneous also their factor of heat conductivity of 0.20 W/(m ̊С). For a thermal protection of a ground part drying chambers the polystyrene having following properties has been used: Density of 1075.0 kg/m , a thermal capacity of 350 J/(kg ̊С), factor of heat conductivity of 0.082 W/(m ̊С). The heat-carrier in given solar dry kiln is air having the following physical and thermophysical property: relations of specific thermal capacities (Cp/Cv) 1.399, and molar weight of 0.0290 kg/mol.In the given work, results numerical modeling for research and an estimation of thermal productivity of drying chamber combined solar-fuel drying installation which is based with cradle-conveyor, heated up by direct receipt of sunlight and an additional source of heat are presented. All calculations have been spent in cases of an “empty” condition drying chamber and “non-working” mode of infrared lamps.Into a database of the given program are entered all thermophysical and physical properties of materials and the substances used in solar dry kiln. Absorbing ability and factor of radiation of a surface of a wall solar dry kiln make chambers (case) 0.90 and 1.0 accordingly where it is made of the processed stainless steel having following properties: the density of 7900 kg/m3 , a specific thermal capacity of 500 J/(kg∙ ̊С), factor of heat conductivity of 16.3 W/(m ̊С), and as the entry condition its temperature has been chosen, equal ambient temperature. In quality translucent coverings have been used polycarbonate sheets having following properties: density of 1200.00 kg/m3 , a specific thermal capacity of 1200 J/(kg∙ ̊С), it has been specified that in them heat conductivity is homogeneous also their factor of heat conductivity of 0.20 W/(m ̊С). For a thermal protection of a ground part drying chambers the polystyrene having following properties has been used: Density of 1075.0 kg/m , a thermal capacity of 350 J/(kg ̊С), factor of heat conductivity of 0.082 W/(m ̊С). The heat-carrier in given solar dry kiln is air having the following physical and thermophysical property: relations of specific thermal capacities (Cp/Cv) 1.399, and molar weight of 0.0290 kg/mol