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What is vacuum frying system?

TIME:2019/7/1 9:41:23

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, apricot, banana, jackfruit, green and gold kiwifruits, carrot, mushroom, potato, shallot, sweet potato and purple yam. Vacuum frying offers an alternative way to improve the quality of fried fruit and vegetables other than by atmospheric frying . The main factors that influence fried products are the frying time-temperature combination of the cooking process; the correct combination of which is necessary to produce a food product with acceptable physical attributes.  Vacuum frying significantly lowered the final oil content in comparison to atmospheric fried vegetables and it also slowed the rancidity of the oil. Most of the benefits of vacuum frying from the low temperatures used and the minimal exposure to oxygen, which reduces the adverse effects on the oil quality, preserves the natural colour and flavour , decreases the acrylamide content and preserves nutritional compounds, such as vitamins and minerals .

Vacuum frying is a good option to achieve high quality dried products with better colors and flavors due to the reduced oxidation, lower frying temperatures and much shorter processing times compared with other techniques . Vacuum fried products are prepared using fresh fruits and vegetables that are peeled and cut into small pieces. The  lower operating pressure which produces a good reduction in the boiling point of water and allows the frying temperature to be lower than 90o C.

The vacuum frying systems available varied in designs but still consist of the same basic parts, namely: a) a vacuum frying chamber; b) a condenser; and c) a vacuum pump. The method of heating the oil in the frying chamber can be gas, steam or electricity. The condenser used water or refrigeration to condense the steam evolved during frying. Shandong Bayi uses Roots vacuum pump and incorporates a means of centrifuging the fried samples within the frying chamber.