Design and Evaluation of a Passive Solar Dryer for Small-Scale Food Preservation | Chapter 5 | Atomic Absorption Spectroscopy and Physical Experiences in Morogoro, Tanzania

 

The use of solar energy has great potential for promoting energy efficiency and reducing the environmental impact of energy consumption in the environment. Solar drying is a very old but continuously explored technology that everyone can use to dry food products from meat, vegetables, cereals and dairy products. However, over time, with increased pollution to both the air and water, the sun drying has been deteriorating. Solar drying provides a safe and reliable environment for the quality of the dried products and their preservative duration. Despite the development of solar energy technologies, high costs and competition with inexpensive fossil fuels have historically limited their widespread adoption. Thus, interest was rekindled in the harnessing of solar energy for heating, cooling, the generation of electricity and other purposes. This study focuses on the design and construction of a solar dryer device intended for drying a variety of food products. The local and cheap materials were selected in the design so as to help local farmers reduce the cost of drying. The principle of the dryer allows lighter hot air to rise up the altitude and cool the surface. In the raising process, warm air comes in contact with the food slices and draws the moisture from them. The repeated cycle of this process makes it a very healthy, low-cost cost long-term drying mechanism. In thermodynamic terms, the sun’s power or heat is used to dry up the moisture content of the fruits or vegetables.  The construction materials were wood, polyurethane glass, mild steel metal sheet and the trays. The optimum temperature of the dryer was 75°C with a corresponding ambient temperature of 28°C. The rapid rate of drying in the dryer reveals its ability to dry food items reasonably rapidly to a safe moisture level. The capital cost involved in the construction of a solar dryer is much lower compared to that of a mechanical dryer. Also, from the test carried out, the simple and inexpensive solar dryer was designed and constructed using locally sourced materials. The temperature inside the drier was found to be about three times than that of the outside atmospheric temperature. As per our experiment the maximum peak temperature inside the drying chambers was 750C during the mid-day (1.00pm) and an average of 570C in a fully sunny day (from 10:00am to 5:00pm). In seven (7) hours continuous drying in one full sunny day under the same climatic condition and in the same time the solar drier can remove maximum moisture contents from the food contents inside the drier for low moisture content food products. Experimental observation shows that the solar drier can be used as an alternative in case of food preservation and the efficiency is also acceptable. The people can make it on their homes especially in the developing countries where the energy demand is high.This chapter of the book is significant because it advocates the sustainable preservation of food using renewable energy. The creation of a passive solar dryer provides a cheap and environmentally beneficial way to lower post-harvest losses. It promotes further research in sustainable energy and agricultural technologies and helps ensure food security.

 

 

Author(s) Details

Yusuf Ismail Koleleni
Physics Department, Muslim University OF Morogoro, P.O. Box 1031, Morogoro, Tanzania.

 

Please see the book here :- https://doi.org/10.9734/bpi/mono/978-93-47485-78-7/CH5

Contribution to the Physicochemical and Microbiological Study of Dried Mango. Comparison of Two Drying Methods (Oven and Solar Drying)| Chapter 7 | Current Overview on Science and Technology Research Vol. 1

 One of the earliest preservation techniques still used by humans is drying. On that, we can go back to the Stone Age. In the food supply chain, dried foods from the market are crucial. Regarding drying in the food business, it may be calculated that fruits and vegetables make up roughly 1% of the total, with grains being the most significant component. The key characteristic of this method is that it reduces the water content of the food to prevent or delay microbial food degradation. At this point, some comprehension can be gained from the terminology used; often encountered words include (drying) or (dehydration). Mangoes of several varieties were dried in two ways (solar and oven). Relative humidity for sun-dried mango is 14.17% 0.01 versus 8.25% 0.01 for oven-dried mango, and the drying yield for sun-dried mango is 33% as opposed to 26%. Compared to oven-dried mango, there is a decrease in dry matter. The mango that has been sun-dried is rich in minerals, vitamin B6, and vitamin C. (Ca, Mg and Fe). But after the drying processes, we also observed that vitamins were present (A, D, and E). Regarding the microbiological requirements, we attained data that complied with the ISO 4833 standard, which regulates the microbiology of the food chain.

Author(s) Details:

Izaora Mwamba,
Department of Chemistry and Industry, University of Kinshasa, Faculty of Sciences, Biochemistry and Food Chemistry Unit. BP 190 KinXI, Kinshasa, DR Congo.

Jean-Noël Mputu,
Department of Chemistry and Industry, University of Kinshasa, Faculty of Sciences, Biochemistry and Food Chemistry Unit. BP 190 KinXI, Kinshasa, DR Congo and Department of Geology, Faculty of Engineering, University of Mons, 9 Houdain Street, 7000 Mons, Belgium.

Please see the link here: https://stm.bookpi.org/COSTR-V1/article/view/7940

Design and Performance Evaluation of an Indirect Solar Dryer: A Recent Study| Chapter 10 | Cutting-edge Research in Agricultural Sciences Vol. 13

Based on meteorological data of mean monthly values of ambient temperature, wind speed, and global solar radiation, which were 22.2oC, 3.64 m/s, and 206 W/m2 respectively, an indirect solar dryer was designed, fabricated, and evaluated in an attempt to reduce post-harvest losses of tomato that gluts in Mubi, Adamawa State, Nigeria, from August to October each year. The projected dryer has a solar collector inclined at an angle of 20.26oC to the horizontal, with an air mass-flow rate of 3.106 X 10-3 kg/s and an overall mean drying rate of 0.140 kg/h. It also had a 0.115 m3/s air volumetric flow rate and 0.065m thick lagging material. During the study months, the dryer determined that drying tomatoes from a postharvest moisture content of 95.6 percent (d.b) to a storage moisture content of 15.8 percent (d.b) took 50.8 hours (d.b). More research is needed to determine the effects of incorporating an additional source of heat or a heat reservoir to ensure day and night drying, which will improve the drying rate and, as a result, reduce drying time, following the development and evaluation of tomato-fruit dryers in other parts of the world. Tomato colour, firmness, flavour, nutritional value, and safety are all affected by the composition of the fruit at harvest and changes in composition during postharvest processing.

Author (S) Details

Bashir Aliyu
Department of Agricultural & Environmental Engineering, Modibbo Adama University of Technology, Yola, Adamawa, Nigeria.

E. K. Bwade
Department of Agricultural & Bio-Environmental Engineering Technology, Federal Polytechnic, Mubi, Adamawa, Nigeria.

View Book :- https://stm.bookpi.org/CRAS-V13/article/view/3821