scholarly journals Development of a Compact Solar Vegetable Dehydrator

2021 ◽  
Author(s):  
S. V Jadhav ◽  
S. S Wangikar ◽  
A. M Kulkarni ◽  
M. K Patil ◽  
A. A Bansode ◽  
...  
Keyword(s):  
Solar Energy ◽  
Moisture Content ◽  
Shelf Life ◽  
Flow Velocity ◽  
Solar Collector ◽  
Agricultural Products ◽  
Hot Air ◽  
Different Temperatures ◽  
Passive Solar ◽  
Time Required

Agricultural products, such as, vegetables are generally perishable and are difficult to store. Drying is one method to reduce the increase their shelf life. Dehydrators use different type of energy as per availability and requirement. Solar dehydrators are more popular since they use renewable solar energy. In this paper such a domestic passive solar dehydrator is designed and analysed for its utility and effectiveness. The dehydrator is designed for converting the perishable agricultural products into powders so that it can be stored and used for longer time. It is designed in two parts. The first part work as a solar energy collector and the second part works as the dehydrator. The heat from solar radiations is imparted to the air in the solar collector. This hot air is used in dehydrator foe drying agricultural products. The experimentation has been performed for different temperatures and flow velocity of air varying for different vegetables depending on their moisture content and time required to remove the moisture. It is observed that drying at different temperature is required for different vegetables to convert them into powder. The taste and colour of the powder produced are found to be good. Therefore, it is suitable and affordable even for farmers with lesser quantity of products.

scholarly journals Mathematical Modeling of the Drying Kinetics of Thinly-Sliced Saba (Musa Balbasiana) Using Hot-Air Dryer

2018 ◽  
Vol 156 ◽  
pp. 02004
Author(s):  
Lola Domnina B. Pestaño ◽  
John Paul T. Bautista ◽  
Reizl JR. H. Leguiab ◽  
Sean Danielle D. Puri
Keyword(s):  
Moisture Content ◽  
Shelf Life ◽  
The Philippines ◽  
Drying Kinetics ◽  
Hot Air ◽  
The Laplace Transform ◽  
Pre Treatment ◽  
C 50 ◽  
Air Dryer ◽  
Best Fit

Banana is one of the top produced crops in the Philippines, and among its cultivars is the Musa balbasiana, commonly known as saba. Due to its high moisture content, saba is perishable and one of the methods to increase its shelf-life is drying. The shelf life of saba can be extended up to six months when dried to 12% moisture content. The research focuses on the effect of banana maturity and choses a mathematical model which will best fit its drying kinetics. The banana samples, the unripe and ripe saba, were bone-dried without pre-treatment using a hot-air tray drier. To produce repeatable data, three trials were done for temperatures 40°C, 50°C and 60°C. Among the three mathematical models used in the study, the treated data for both unripe and ripe saba best fit the Laplace Transform Model. Using Lagrange interpolation, the time per trial was computed; unripe saba dried at 50°C achieved the ideal moisture content in an average time of 87.5574 minutes for the three trials while that of ripe saba dried at 40°C achieved the same moisture content in an average time of 88.8619 minutes for the three trials. With the increase in temperature, the discoloration decreased indicating an enzymatic character ofbrowning.

scholarly journals Changes in Microbiological and Physicochemical Quality of Dried Persimmons (Diospyros kaki Thunb.) Stored at Various Temperatures

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Jeong-Eun Hyun ◽  
Ji-Yeon Kim ◽  
Eun-Mi Kim ◽  
Jong-Chan Kim ◽  
Sun-Young Lee
Keyword(s):  
Moisture Content ◽  
Shelf Life ◽  
Color Index ◽  
Visual Quality ◽  
Microbial Populations ◽  
Diospyros Kaki ◽  
Visual Appearance ◽  
Different Temperatures ◽  
Yeasts And Molds

This study was conducted to investigate the microbiological, physicochemical, and visual quality of dried persimmons (Diospyros kaki Thunb. cv. Cheongdo-Bansi) during storage at various temperatures in order to determine the shelf-life. Two commercial dried persimmon samples were evaluated for changes in weight, moisture content, color, texture (hardness and gumminess), and microbial populations during storage at different temperatures (−20, 5, 12, and 25°C) for 70 days. Overall, dried persimmon-2 showed lower levels of total mesophilic bacteria, Escherichia coli, coliforms, yeasts, and molds than dried persimmon-1. Among the physicochemical qualities, significant differences were observed in color parameters such as L∗, a∗, and b∗ of the dried persimmons. However, no significant differences in weight, moisture content, and texture were observed in dried persimmons during storage for 70 days. Thus, changes in visual appearance and color index such as chroma value and browning index can be used as indicators for determining the shelf-life of dried persimmons.

scholarly journals Design, Building and Performance Evaluation of a Mixed-Mode Solar Dryer for Agricultural Products

2020 ◽  
Vol 15 ◽  
Keyword(s):  
Performance Evaluation ◽  
Relative Humidity ◽  
Moisture Content ◽  
Ambient Temperature ◽  
Solar Collector ◽  
Mixed Mode ◽  
Ambient Air ◽  
Agricultural Products ◽  
The Third ◽  
And Performance

This research work presents the detailed explanation of the design, construction and performance evaluation of mixed-mode solar agricultural products dryer. The experimental set up used for testing the performance of the mixed-mode solar agricultural products dryer and determining the influence of various drying methods on the drying behaviour of agricultural products. Evaluation of the dryer was centered on the moisture content reduction, temperatures and relative humidities variations. 1680 g of freshly potato slides were used for evaluation. The test results gave that the temperatures inside the dryer cabinet and the solar collector were much higher than the ambient temperature during most hours of the daylight. The temperature inside the solar collector was up to 27 o C approximately higher than the ambient temperature. The temperature inside the drying cabinet was up to 22 o C approximately higher than the ambient temperature for about three hours immediately after 12.00 h (noon). The relative humidity in the solar collector and drying cabinet were lower than the ambient air relative humidity, with the ambient air recording the highest relative humidity at each reading followed by the drying cabinet and finally by the solar collector. Because of the decreased relative humidity inside the dryer, all the time, the temperature inside the dryer was high which is sufficient enough to dry the potato at an early time. Based on the results obtained during the test, temperature above 65 o C was recorded inside the drying cabinet. This high temperature in the drying cabinet causes 419 g of moisture to be removed on the first day, 257 g on the second day, 191 g on the third day, 136 g on the fourth day and finally 108 g on the fifth day. At the end of the five days of drying process, the mass of 1680 g of potato was reduced to 569 g. Total amount of moisture removed was 1111 g and total moisture loss was 66.1 %, which is the required amount of moisture to be removed for safe drying of freshly potato slides. The moisture content of the freshly potato slides was 24.9 % at the end of drying for the first day at about 5:00 pm, 20.4 % at the end of drying for the second day, 19 % at the end of drying for the third day, 16.7 % at the end of drying for the fourth day and finally 15.9% at the end of drying for the fifth day. It was observed that the drying rate increased from the end of one day to another, which shows the earlier and faster removal of moisture from the dried item.

scholarly journals Teknologi Kolektor Surya Berlubang tanpa Kaca Transparan untuk Mengeringkan Daun Gaharu

2018 ◽  
Vol 38 (2) ◽  
pp. 227
Author(s):  
Irwin Bizzy ◽  
Budi Santoso ◽  
Muhammad Zahri Kadir
Keyword(s):  
Wind Tunnel ◽  
Moisture Content ◽  
Solar Collector ◽  
Input Parameter ◽  
Agricultural Products ◽  
Solar Irradiation ◽  
Efficiency Evaluation ◽  
Collector Plate ◽  
Engineering Department ◽  
Simple Technology

The perforated solar collector technology is a highly potential solution to take advantage of renewable energy in tropical countries such as Indonesia. This technology can be applied as a simple technology for drying of agricultural products. This study aims to determine the rate of the decreased moisture content of gaharu leafs. In this study, the perforated solar collector equipped with four ribs was used. The efficiency evaluation of perforated solar collector plate was conducted in Wind Tunnel-Rig, Basic phenomenon Laboratory of Mechanical Engineering Department, Sriwijaya University. The dimension of the plate is 850 mm × 300 mm × 1.5 mm, which has 1018 holes with 2.5 mm in diameter. The results show that the drying rate for achieving the 10% moisture content of the gaharu leafs, can be reached in 2–3 days. This condition occurs when the weather is sunny, or not cloudy and rainy. In other condition, when the sunshine with an average solar irradiation on the surface is greater than or equal 500 W/m2. The efficiency tests of the perforated  aluminum plate solar collector using wind velocity as input parameter show that the blackened plate resulted in better performance (12,83%) than the colorless one in (6,36%). ABSTRAKTeknologi kolektor surya berlubang ini merupakan salah satu solusi untuk dapat memanfaatkan energi baru terbarukan yang peluangnya sangat besar untuk dikembangkan di negara beriklim tropis seperti negara Indonesia. Teknologi ini dapat digunakan sebagai teknologi tepat guna untuk mengeringkan produk-produk pertanian. Tujuan penelitian ini adalah untuk menentukan laju penurunan kadar air daun gaharu. Dalam pengujian pengeringan ini digunakan kolektor surya berlubang bersayap empat. Evaluasi efisiensi pelat kolektor surya berlubang dilakukan di Wind Tunnel Laboratorium Fenomena Dasar, Jurusan Teknik Mesin, Universitas Sriwijaya. Dimensi dari pelat kolektor surya berlubang adalah 850 mm x 300 mm x 1,5 mm, dengan jumlah lubang 1.018 buah yang berdiameter 2,5 mm. Hasil penelitian menunjukkan bahwa laju pengeringan daun gaharu untuk mencapai kadar air 10 % dapat dihasilkan dalam 2 ¸ 3 hari.  Kondisi ini terjadi bila cuaca cerah, tidak hujan dan tidak berawan. Dalam kondisi lain, ketika matahari bersinar dengan radiasi matahari rata-rata yang mencapai permukaan lebih besar atau sama dengan 500 W/m2. Pengujian efisiensi kolektor surya pelat alumunium berlubang dengan parameter kecepatan udara, menunjukkan bahwa pelat berwarna hitam menghasilkan performansi yang lebih baik (12,83%) dibandingkan dengan pelat tanpa warna (6,36%).

Diffusion of Water in Chestnut Fruits during Drying and Rehydration Processes at Different Temperatures

2008 ◽  
Vol 273-276 ◽  
pp. 758-763
Author(s):  
Ramón Moreira ◽  
Francisco Chenlo ◽  
L. Chaguri ◽  
Christiana Fernandes
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Convective Drying ◽  
Transfer Processes ◽  
Hot Air ◽  
Mass Transfer Processes ◽  
Different Temperatures ◽  
Diffusional Model ◽  
Kinetics Of

Many food materials must be dried in order to decrease its water activity and to increase the shelf-life. Also, rehydration operation must be carried out as previous step before consumption. Both operations are commonly employed in some industrial chestnut processing. These processes can be carried out at different temperatures and in all cases the quality of the final product can be affected. In this work, convective drying with hot air is the employed method for water removal and rehydration is carried out by immersion of chestnut in water. In both cases, mass transfer processes are governed by water diffusion in the bulk of the solid. The aim of this work is to determine experimentally the drying and rehydration kinetics of chestnut samples at different conditions of temperature and moisture content. Obtained data are modeled with a diffusional model taking into account volume variations and the corresponding values of the coefficients of diffusion of water are obtained. Analysis of the results indicates that drying/rehydration rates increase with temperature and rehydration kinetics are also depending on the initial moisture content of chestnut. Finally, leaching flow during rehydration is only important at high temperature due to starch gelatinization processes.

scholarly journals Analisis Perubahan Waktu Pengeringan Terhadap Variasi Tinggi Cerobong

2019 ◽  
Vol 22 (1) ◽  
pp. 1-8
Author(s):  
Muhammad Syafrun
Keyword(s):  
Solar Energy ◽  
Water Content ◽  
Mechanical Engineering ◽  
Engineering Faculty ◽  
Hot Air ◽  
Time Required ◽  
Zinc Plate

This study aims to find out the efficiency of grain dryers using a chimney and a fan as suction air from the collector into the drying chamber.The research was conducted at the Central of Laboratory Department of Mechanical Engineering Faculty of Engineering, University of Muslim Indonesia, Makassar. A dryer was made from a zinc plate of 0.2 mm as collector by using a hot-air and solar energy as a drying medium. It was expected that this tool can  dry grain quickly with evenly distributed drying level or water content. There were five variations of  the Chimney : 20 cm, 50 cm, 80 cm, 110 cm and 140 cm with the grain thickness of 7 cm, 5 cm and 3 cm. The data were then analyzed to obtained the efficiency of the dryer. The results reveal that the time required to lower the water content of the harvest grain from 24.6% to 13.6% - 13.85% of milled moisture was 4 hours - 6.5 hours with an efficiency of 34,232 % for grain thicknes 7 cm, 31,480 % for grain thicknes 5 cm and 30,122 for grain thicknes 3 cm at 80 cm chimney height.

Impact of drying method of figs with small-scale flat-plate solar collector

2016 ◽  
Vol 13 (5) ◽  
pp. 407-412 ◽  
Author(s):  
Fahim Ullah ◽  
Min Kang ◽  
Lubna Hassan ◽  
Ninghui Li ◽  
Jun Yang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Flat Plate ◽  
Solar Collector ◽  
Agricultural Products ◽  
Ficus Carica ◽  
Solar Irradiation ◽  
Small Scale ◽  
Content Type ◽  
Flat Plate Solar Collector ◽  
Drying Chamber

Purpose The purpose of the study was to develop a performance flat-plate solar collector that would be used as a solar drier for fruit fig (Ficus carica L). This study proposes how and why solar energy is important for drying the agricultural products. This study aims to expand the domain of solar collector for different purposes and, most important, for agricultural resource normally found in the literature. Design/methodology/approach The paper opted for an exploratory study using the flat-plate solar collector with drying chamber for drying purposes of agricultural products. During the experiment, the data were collected with moisture content, drying rate of the product and solar irradiation falls on the collector. Findings This paper describes that how flat-plate collector works for agricultural products and how to reduce the moisture content in the product (fig). Efficiency of collector was evaluated under the ambient temperatures of 24°C. Efficiency also significantly increased from 53 to 55 per cent with an increase in ambient temperature from 22 to 24 °C. Figs (Ficus carica L) were dried in the drying chamber of the flat-plate solar collector. The products were dried at temperature of 55-65°C and 15 to 20 per cent humidity. Research limitations/implications Because of this research chosen, the research results are beneficiary for agricultural users for drying purposes. Therefore, the researchers are encouraged to dry the agricultural product with flat-plate solar collector, because it reduced the moisture content of the product very fast. Originality/value This paper fulfills an identified need to study that how flat-plat solar collector can be used.

scholarly journals Effects of Moisture Content and Drying Method on Shelf Life and Quality of Coconut Residue

2021 ◽  
Vol 56 (2) ◽  
pp. 443-450
Author(s):  
Rittichai Assawarachan
Keyword(s):  
Moisture Content ◽  
Shelf Life ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Fluidized Bed Drying ◽  
Flash Drying ◽  
Fresh Coconut

In this article, the quality changes and shelf life of by-products (coconut residue) obtained after coconut milk extraction were studied using three drying technologies: hot air drying, fluidized bed drying, and flash drying. Among the drying technologies, flash drying was most suitable for fresh coconut residue. It gave the least moisture content with the most stability of whiteness and oil content and the highest drying rate. Dried coconut residue using flash drying has the longest shelf life up to the 140th day with slight changes in the quality when stored in warehouse conditions of 35±1.0oC and 60-75% relative humidity. In terms of specific energy consumption, flash drying required the lowest energy of 8.47±0.50 MJ per kg water removal from fresh coconut residue, whereas hot air drying consumed the highest specific energy.

scholarly journals Composition Changes in Lycium ruthenicum Fruit Dried by Different Methods

2021 ◽  
Vol 8 ◽  
Author(s):  
Youyuan Lu ◽  
Xiangfeng Kong ◽  
Juanhong Zhang ◽  
Chao Guo ◽  
Zhuo Qu ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Moisture Content ◽  
Shelf Life ◽  
Total Phenolic ◽  
Drying Methods ◽  
Hot Air Drying ◽  
Air Drying ◽  
Sun Drying ◽  
Hot Air ◽  
Lycium Ruthenicum

The fruit of Lycium ruthenicum (LRF), known as black wolfberry, is a medicinal and edible fruit. The fresh LRF is perishable and has only about 3 days of shelf life. Drying could prolong the shelf life of LRF. However, it could imply physical changes and chemical modification. This study evaluated the effect of sun drying (SD), hot air drying (HD), and freeze drying (FD) on the appearance characteristics, moisture content, bioactive compounds, amino acid composition, and antioxidant activity of LRF. The results showed that LRF dried by FD was round, expansive, fragile, and maintained the largest amount of appearance traits among the three drying methods. Drying methods had a significant effect on phytochemical content and antioxidant activity of LRF (P < 0.05). Principal component analysis (PCA) showed that procyanidin content (PAC), asparagine (Asn), total phenolic content (TPC), total anthocyanin content (TAC), and moisture content were the main sources of the difference in LRF dried by different methods. The characteristic of LRF in FD was low moisture content, and high TPC, Asn, PAC, and TAC. Sun drying was opposite to FD. Hot air drying was high TPC and low TAC content. The quality of LRF was in the order of FD > HD > SD based on comprehensive evaluation of the phytochemical component content and antioxidant capacity. Additionally, the water temperature and soaking time had different antioxidant activity effect on LRF dried by different methods. These findings will provide useful information for production and utilization of LRF.

scholarly journals Development of an Automated Solar Powered Hot-air Supplemented Dryer

2019 ◽  
pp. 1-14
Author(s):  
O. Taiwo Aduewa ◽  
S. Ajiboye Oyerinde ◽  
P. Ayoola Olalusi
Keyword(s):  
Solar Energy ◽  
Moisture Content ◽  
Initial Moisture Content ◽  
Climatic Conditions ◽  
Solar Drying ◽  
Drying Time ◽  
Drying Temperature ◽  
Hot Air ◽  
Solar Powered ◽  
Drying Chamber

The world is facing two major challenges: one is to meet the exponential growing demand for energy particularly in developing and underdeveloped countries and other is to deal with global, regional and local environmental impacts resulting from supply and use of conventional energy. The cost-effective technology for solar drying that can be easily adopted among the rural farmers of developing countries needs to be developed in areas where solar energy is abundantly available. As cheap as the solar energy could be, there are associated problems with the stability of the energy for different purposes due to instability of climatic conditions. For this research, a solar powered hot-air supplemented dryer (SPHSD) with a capacity of 20 kg of sliced yam was designed and developed. The SPHSD has three sections which are solar collector chamber, drying chamber and hot-air supplement chamber which is powered with two 150-watt solar panel and a 200 amps solar battery for continuous operation during bad weather. All data were logged digitally for accuracy and test was done using yam slices. Difference in drying time and stability in drying temperature was evaluated using SPHSD and indirect solar dryer. The result shows stability of temperature in the drying chamber when SPHSD was used while the drying temperature fluctuates throughout the indirect solar drying test period. Drying experiment was conducted for 481 minutes (between 0910 hrs to 1713 hrs) reducing the moisture content from 71.91%, 72.1% and 72.8% to 27.95%, 25.78% and 28.23% for MC1, MC2 and MC3in wet basis respectively. Drying experiment was conducted for 832 minutes (between 0901 hrs to 2257 hrs) reducing the moisture content from initial moisture content levels of 72.66%, 71.48% and 71.48% to 13.47%, 12.53% and 12.54% for MC1, MC2 and MC3in wet basis respectively.

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