Lessons in Development: Native fruit drying technology in Bamyan, Afghanistan
Last winter, I was on a business tour of Bamyan and saw a unique machine at a friend’s home. Jahid is my friend who lives, in a remote village named Azdar near the historical town Bamyan in Afghanistan. Upon my query Jahid explained the purpose and the working of machine. I found the machine best fit for farmers of Hunza too, as both Bamyan and Hunza have a similar weather pattern. The machine will be an alternate tool for fruit preservation and may be a replacement of the technique in which fruit being dried is exposed to the fumes of Sulfur dioxide. Jahid also offered me some dry apricots which were dried using the machine. I was impressed by its wonderful natural taste and fabulous hygiene condition. With almost no maintenance cost, no input energy cost, less occupied area and good aesthetic look, its use and construction is very simple with one time investment of about 3 to 4 thousand rupees.
Basically the machines has two main parts, an upper portion where the fruit is kept for drying and a lower inclined box with its top covered with a glass. Both portions are connected to each other in a way that the air moves from one part to another easily. The upper portion has shelves where the fruit is kept for drying. The shelves in the upper portion can be easily rolled out to install the fruit for drying. After the fruit is installed the shelves are rolled back into the box. The inclined lower portion makes the transport of the air from one portion to other easy.
The working of the tool is so simple. The air in the lower glass covered box gets hotter when it gets light and due to advection and convection the air moves to the upper portion of the tool. This is because the hotter air has less density and colder air which is heavier moves down. The hot air interacts with the fruit and dries it by exchanging heat .After losing heat to the fruit the air gets cooler and moves to the lower portion where it again gets warmer by the solar rays and the same cycle goes on. Simple every day science is involved but in a very efficient way. The outer cover of the box not only safeguards the fruit from dust but also save energy giving air a limited path to move.
Generally, in Gilgitbaltistan and other areas these fruits are being dried by placing under direct contact to the Sun with or without supply of sulfur dioxide (SO2) smoke (gas). The dried fruit without cover of SO2, usually turns black (but holding natural taste to an extent) and if not covered properly from winds, the fruit gets dust particles which lesser the taste, total value and attraction of the potential buyer. On the other hand although drying under the cover of SO2, produces good attractive color but the taste of the fruit always turns acidic. Apart from that the health and environmental effects of SO2 are dangerous and consequences are not known to producers, merchants and end users.
I would suggest to the local management of Aga Khan Cultural Service Pakistan’s (AKCSP) in Hunza and Women Social Enterprise (WSE), Altit to copy this this product and offer it to farmers at affordable price. I am sure this will make all time sale record of WSE products.