What’s the vacuum frying?

  Vacuum frying is a frying process that is carried out at pressures well below atmospheric level. It has been used for different foods, but mostly fruits and vegetables. The latest reports include apple, carrot, mushroom, potato, sweet potato and purple potato etc. Vacuum frying offers an alternative way to improve the quality of fried fruit and vegetables other than by atmospheric frying.

How About the Vacuum frying process?

  Vacuum fried products are prepared using fresh fruits and vegetables that are peeled and cut into small pieces. The operating pressure used is usually lower than 7 kPa which produces a good reduction in the boiling point of water and allows the frying temperature to be lower than 90°C.

  The vacuum frying system consisted of a vacuum frying chamber, a water-cooled condenser using a cooling tower and liquid ring vacuum pump.

 The vacuum frying process required the heating of oil to the required temperature. Then the sample to be processed was placed in the basket inside the frying chamber but suspended above the hot oil. The pressure inside the vacuum frying chamber was reduced to the required pressure. The sample was then lowered into the hot oil for the required duration and then the basket was raised above the oil and then centrifuged within the chamber for the required speed and time. 

  The fried product can also be taken out of the chamber and centrifuged using a separate machine or stood in the frying chamber to drain the surface oil. The product was then placed on absorbent paper, cooled and packed in an aluminium laminate bag with or without nitrogen flushing.