Currently, there are many studies related to the field of drying agricultural products that have been conducted in the country. However, the intensive research and manufacture of specialized equipment for the production of dried dragon fruit on an industrial scale is still very limited. Face with that fact, the group of authors at Ho Chi Minh City Polytechnic University has implemented the project "Research and manufacture a dragon fruit vacuum dryer with a capacity of 500kg/batch."

The system manufactured by the author group includes: vacuum drying chamber, heating assembly for drying rig, drying rig system, condensing unit separating water from moisture escaping from the drying chamber, vacuum pressure pump assembly, equipment cooling tower and control system assembly. The machine has a maximum drying temperature of 70 degrees Celsius, a vacuum pressure of 720 mmHg, an average drying time of 18 hours/batch, and is applied IoT technology in temperature monitoring of the drying process.

Dragon fruit products after being dried. Photo: NNC

The complete solution has been put into trial operation on an industrial scale at HG Food Joint Stock Company, with the results that the quality of the finished product after drying meets the set standards of food safety, nutritional criteria, pieces of dragon fruit are crispy and porous, the moisture content of sliced dragon fruit after drying is 1.8-3% WB, the content of vitamin C retained after drying reaches over 92%, Keep the color fresh (The indicators are analyzed at Intertek Vietnam Limited).

Assoc. Prof. Dr. Tran Anh Son, auther said that from the above-mentioned background of the dragon fruit vacuum dryer, it is possible to continue researching drying applications for other product groups, such as mango, jackfruit, banana, pineapple and etc.