Food processing technology continues to evolve over time. The development of this technology is driven by the increasing need of human food caused by the increasing number of world population. At the same time, the area of food-producing land is narrowing. This leads to the need for food processing technologies that improve the quality and quantity of food products; one of them is food drying technology.
Drying is an event of mass transfer and energy occurring in the separation of liquid or moisture from a material to a defined water content limit using a gas as a heat source fluid and a liquid vapor receiver. Food drying has two main goals. The first objective is as a means of preservation of food. Microorganisms that cause food damage can not develop and survive in environments with low moisture content. In addition, many enzymes that cause chemical changes in food can not function without water. The second objective is to minimize the cost of distribution of foodstuffs because the dried food will have a lower weight and smaller size.
Drying is the process of removing some water from the material. In drying, water is removed by the principle of the difference in humidity between the air dryer and the dried foodstuff. The material is usually contacted with air dry which then displaces the mass of water from the material into the air dryer.
Currently there are many dryers that have been made in the market, but the tool is expensive, using electricity and tools that use the sun is relatively difficult to make your own community so that small communities difficult to obtain the tool, so need to make a cheap dryer from the material easy in can and can be used to dry various types of food and crops.
To make this tool used, we general tools of carpentry, such as hammer, saw, meter, scissors and others, while the material used is wood batten, gauze, mica / glass, nails, board.
The first we made a kind of triangle prism with a height of 60 cm and width of 60 cm and given the feet with a length of `10 cm from the ground, giving the foot this drying does not touch the ground directly, the angle of the triangle is 45 degrees which aims to get wide surface of the clothesline seideal possible.
The length of the side of the incline or the top surface of the clothesline is 85 cm and its width is 60 cm. This size is a household scale or for aeration and when used for large scale then live measure the size of this tool.
At the center of the triangular prism frame is mounted square with different area, for the bottom is the widest part with the size 46 x 56 cm, the bottom is coated with a gauze with a relatively large hole with the above with the intention that the water can be directly out through the bottom of this dryer.
The bottom is suitable for drying the still-moist foods with high moisture content, on a second rectangle using size 46 x 32 cm, this section is coated with a more rigid gage than the lower gauze so that the water is not falling down, this section is suitable for feeds that are relatively fewer moisture content than the bottom, the third or the top of the box using 46 x 24 cm, this section is covered with a relatively denser rich with the bottom, this part is suitable for drying the smooth food such as flour and so forth.
In the picture below is a form of tool that is almost formed. The top of the tool is lined with thick mica or glass that function to receive sunlight and retain water entering the food. The side of the tool is also given a screen that aims to dust dust does not freely enter, but the wind can still enter for circulation so that the drying process can be faster. On the back of this tool is closed using a plywood board mounted hinges to be opened the lid. The back of this function for the entry and discharge of food on this tool. In making this wood is also polished to be more durable and good.
The sunlight coming into this tool will illuminate the product directly. Besides, the incoming solar heat in this tool is still stuck in this tool so as to generate sufficient heat in this tool, the incoming sunlight will increase the temperature of the room in the “greenhouse” cupboard that will help speed up the drying process of the product. The temperature inside this tool can reach 50ºC. To speed up the drying process, the moist air generated by the evaporation of water from the product will be passed through the sides or bottom of the tool made of wire mesh with certain holes that allow air to circulate. So relatively dust-free and when the rain is not exposed to water.
In this sunning system the energy from the sun is utilized in two ways,
(1). Direct irradiance of product (Thermal Energy),
(2). Increased room temperature through greenhouse effect and heat absorbent plate
In this experiment the tool is used to dry the crackers and fish, the test results are found that two days of drying has made the crackers and fish in drying in the dry in comparison with the usual way of drying. Besides drying with this tool is relatively safe from the disturbance of animals or the presence of dust and not worry when it rains and we forget to enter the tool