Preservation of farm produce is one of the main challenges farmers face in developing countries. Solar drying can help to solve this problem. It involves reducing the amount of food lost due to a lack of proper food preservation methods.
Various types of solar dryers have been designed to overcome this problem. The type of drier depends on the product and the drying process.
What is drying?
Drying is a process of moisture removal. It is a classical method of food preservation. Many products, however, must be dried at temperatures that are relatively less than 80 Degrees Celsius to achieve their desired quality.
Open sun drying is the most commonly used method to preserve agricultural products such as grains, salt, fruits, spices, meat, fish, and vegetables in most developing countries.
Types of solar dryers.
- Direct dryers. Direct solar rays heat the product. It is hard to control the temperature. this can lead to over/under drying.
- Indirect dryers. The product is heated by moving air outside the drying chamber. Air flows from the outside to the inside.
- Combined dryers. The product is dried by both direct heat and moving hot air.
Why should you use a solar dryer?
- Retain the quality and quantity of the produce.
- Reduces losses. Once the food is dried and stored it can be used at a later date. Little to minimal food is wasted by decomposition.
- It does not use fossil fuels. Pollution to the environment is minimized.
- It is affordable. The materials are sourced locally hence the low cost of production.
- It doesn’t require electricity. It can be used in remote areas.
- It is safe and hygienic. The food is dried in a controlled environment. It is less likely to be attacked by pests and mold.
What to consider before acquiring a solar dryer.
- What food is the dryer going to be used for? Grains, fruits, and veggies require different drying techniques.
- What quantity of food is going to be dried? This will determine the size of the dryer being used.
- What are the climatic conditions during harvest and drying seasons?
- Is the food going to be stored for a long period or is it going to be shipped to the market for consumption? This will determine the dryness of the final product.
Disadvantages of using a solar dryer.
- Not useful during cloudy weather.
- It needs constant supervision. The temperature should not be too high to too low.