Dehydration onions is an important onion processing technology because it can extend the shelf life of onions and facilitate storage and transportation. But what is the process of dehydration of onions?
- Raw material acceptance
The factory first conducts a strict quality inspection on the onions shipped in, including an assessment of appearance, size and freshness. Only onions that meet the standards can enter the subsequent processing process.
- Onion root cutting
The first step is to remove the roots of the onion, which is mainly done by mechanized equipment. The root cutting machine can accurately remove the roots at the bottom of the onion while keeping the basic shape of the onion intact.
- Peeling
After cutting the root, the onion will enter the peeling equipment. The surface of the peeled onion is smooth and clean, which is suitable for subsequent processing.
- Slicing or dicing
Depending on customer needs, onions are processed into different shapes, such as rings, dices or strips. This step is usually completed by a slicing machine or dicing machine, which can adjust the cutting thickness and size to meet specific requirements. For example:
Rings: Usually 2-4 mm thick, suitable for making dried onion rings.
Dicing: The particle size is generally 3-10 mm, used to produce onion granules.
- Dehydration
Dehydration is the core of the whole process. The processed onions are fed into the drying machine. Common industrial drying methods are:
Hot air drying: hot air is used to evaporate the water in the onions. The onions are evenly spread on the conveyor belt and dried in a multi-layer drying machine.
The drying temperature is generally controlled at 50-70°C, and the time is determined by the thickness and shape of the onions, usually 4-8 hours. The moisture content of the final product must be controlled below 5%.
- Screening and packaging
After drying, the onions are screened to remove oversized pieces or fine debris, and then weighed and packaged.
- Storing
To extend the shelf life of dried onions, they need to be stored in a cool, dry place.
During the onion drying process, each step requires strict quality control to ensure the stable quality and safety of the final product.