Many food snack food industries has been trying to reduce the fat content of fried products without deteriorating their desirable organoleptic characteristics, a vacuum frying process is becoming an alternative.
Vacuum frying improves the quality of the fried food and could reduce the final oil uptake in the product.
The product is heated at low pressure, decreasing the boiling points of the water in the product and thus, the lowing the frying oil temperature.
Saturated Steam Table by Pressure
kPa abs
Saturated steam temperature
Specific enthalpy of statured steam
3KPa
24 ℃
2545 KJ/Kg
10KPa
45.8℃
2584 KJ/Kg
101.3KPa
100℃
2675KJ/Kg
Under Frying, a frying temperature is available. Low frying also means an energy saving operation.
Moreover, the absence of air during vacuum frying inhibits enzymatic browning, and therefore, the color and nutrients of snacks can be largely preserved.
Absence of air during vacuum frying also inhibits the frying oil lipid oxidation, therefore, extend the service life.
A further benefit of vacuum frying is the ability to minimize formation of acrylamide by frying at lower temperature.
The commercial vacuum fryer, either batch operated small scale vacuum fryer or continuous operated automatic vacuum fryer, boils off product moisture at a lower temperature to produce snacks, so that high sugar food products that could not be turned into snacks with a traditional frying system, can now be processed into innovative snack products.
