What is deep Fry?

Deep fry is cooking measure of submerging food inside of heated oil or fat.

The Process…
The food is cooked by heating exchanging of oil or fat bath. Since temperature of oil or fat bath can be a lot hotter than water bath, it would take less amount of time to mature food relatively. During deep fry process, protein inside of food is denaturized if there is any; at the same time, the outside protein would protect the inside ones from being further denaturized. That’s the reason why food intends to be crispy outside and tender and juicy inside when deep fry is processed.

Advantage…
Since temperature of deep fry is a lot higher comparing with water cooking, the vaporing being gasified will stop hot oil from getting to deeper part of food at the same time when vapors  moves at the counter direction of oil getting inside, the food being cooked with proper time and temperature will be crispy outside and tender inside. Most of protein and other nutrition will be bonded inside. Deep fry create great taste and flavor. Inside of food, is just not as rich as it was looked from appearance. 
Disadvantage…
Most of disadvantage of deep fry are lead by improper way of process. 
Acrylamide can be generated when food is fried for too long time with too high temperature. It might bother health when people take deep fry food very often and those foods are not processed with correct temperature, time and oil. 

Frying oil can be hazard when it is hot. Waste oil is more often to be processed to bio-diesel. Waste oil is potential pollution when it is not processed in the correct way. 

Why do we use pressure fry?

Pressure Fry, especially minus pressure fry, results in great advantage comparing with conventional one. 
Flavor
inside tender and Juicy. Food and oil are sealed in the pot, that’s why nutrition, flavor and juice are sealed.

Lower Fry Temperature
Minus pressure fry results in a lower oil boiling point, the result is that the fry temperature is lower than when it is in standard open ambient. It would create same amount of turbulence as foods are fried for heat exchange.
Less Fry time
The lower boiling point results in turbulence that oil goes more aggressively with food being fried. Less fry time means healthier, less consumption of energy and oil aging. 
Longer Oil Service Life
Fry happens in a sealed compartment. That’s why oil is a lot slower in the process of being oxidized.