Onion drying process/onion drying machine

Onion is a multifunctional health food. It is native to central and West Asia. There are many different varieties of onions, which are used in food all over the world. It is rich in a variety of nutrients and is very popular. Drying onions into onion powder can effectively improve the shelf life of onions and facilitate transportation. 

The drying of onions is becoming more and more popular, especially among onion manufacturers. So how to make dried onions? What are the machines for drying onions? Next, let's learn about the onion drying process and how to choose the right onion drying machine. There are two ways to dry onions, one is to dry the onions in the sun, and the other is to use a professional dryer to dry them. So, let me share with you the process flow and advantages and disadvantages of these two methods.

In a traditional way: sun drying of onion:

Step 1. wash the onion and select the ones with poor quality during the washing process.
Step 2. then cut the onions and place them evenly on the tray. Do not stack them too much to affect the drying effect.
Step 3. dry them in the sun for 2-3 days.
This traditional method of drying onion is economical and does not require any investment. However, because the drying effect is greatly affected by the environment and is not easy to control, the drying color of onion is uneven, and even defective onion may appear. During the drying process of onion, a certain amount of manual turnover is required. What’s more, if you have a large amount of onions, and the traditional drying process is time-consuming and labor-consuming, then you need a professional onion drying equipment.
And most onion product manufacturers use the second processing method--onion drying machine.

In a professional mechanical way: drying and processing of onion:

This drying method is to use onion drying equipment to carry out reasonable dehydration of onion. It can not only solve the shortcomings of the traditional method of drying onion, but also improve the yield and increase the efficiency of drying onion. At present, onion drying room and mesh belt onion dryer are widely used. Let me introduce to you the usage and drying principle of the two machine.

Heat pump dryer

Step 1. Due to the different quality and maturity of onion, unsuitable onion should be selected before drying.
Step 2.To clean the surface dust of onion, if the output is large, it is recommended to use a professional onion cleaning machine.
Step 3. Then slic the onions, if the output is large, it is recommended to use a professional onion slicing machine
Step 4. Spread the onion evenly on the tray with a thickness of about 5 cm, and then put them in the drying oven.
Step 5. Set the temperature in the drying room to 65°C and the humidity to 10%. Dry for 6~8 hours to complete the onion drying.
Step 6. The dried onion will regain moisture when they are in direct contact with the air, so a sealed package is required. If you use vacuum packaging, you can better preserve the color and aroma of onion.
If we use the onion drying oven, the equipment is equipped with a small cart with a tray and a tray rack. The heat source of the onion drying room is air. The heat in the air is absorbed by the heat pump compressor. After compression and release, a large amount of high-temperature hot air can be obtained, so as to realize the continuous and uniform drying and processing of onion.

Mesh belt dryer

Step 1. Due to the different quality and maturity of onion, unsuitable onion should be selected before drying.
Step 2. To clean the surface dust of onion, if the output is large, it is recommended to use a professional onion cleaning machine.
Step 3. Then slic the onions, if the output is large, it is recommended to use a professional onion slicing machine
Step 4. Place the onion on the conveyor belt of the onion dryer. The onion is spread on the feeder by the homogenizing device on the conveyor belt.The stacking thickness of onion is 10-20CM. 
Step 5. After the onion enters the onion dryer, it runs in an "S" shape in the machine. The transmission part of the onion dryer adopts a variable-frequency speed-regulating motor, which can control the internal operation time of the drying according to the difference of the water content of the onion.
Step 6. The dried onion will drain through the last layer.
If we are using a mesh belt type onion dryer, then this equipment has a wide range of heat sources, such as coal heating, gas heating, steam heating, biomass pellet heating, or electric heating. It is a multi-layer continuous drying structure. The onions are dried and dehydrated layer by layer from top to bottom. The drying speed is fast and the production efficiency is high. It is very suitable for the drying and processing of large quantities of onions.

Having learned about the above two kinds of dryers, let me introduce you how to choose a dryer suitable for you.

How to choose a suitable onion dryer

First of all, it depends on our demand for onion processing. For large output, use a onion mesh belt dryer. Generally, the output of a onion mesh belt dryer is 300-2000kg/h. For small output, the output of a heat pump dryer is 100-5000kg/batch. Oven length and mesh belt layers can be customized. We can choose and match them reasonably according to our own processing requirements.
Onion drying process is becoming more and more popular in the world, and onion drying also has bright prospects. Do you want to start a onion business? If you want to know more professional questions about onion drying, please feel free to contact us online!

Onion Drying process video：