Vacuum fryer
Encyclopedia
A vacuum fryer is a deep-frying device housed inside a vacuum
chamber. It was originally developed for potato chip
production.
Vacuum fryers are fit to process low-quality potato
es that contain higher sugar levels than normal, as they frequently have to be processed in spring and early summer before the potatoes from the new harvest
become available. With vacuum frying it is easier to maintain natural colors and flavours of the finished product. Due to the lower temperature
s applied (approx. 130°C), the formation of suspected carcinogen
acrylamide
is significantly lower than in standard atmospheric fryers, where the frying temperature is approx. 170°C. The fat
absorption of the products is also reported to be lower than in atmospheric fryers. In South East Asia (mainly Philippines
, Thailand
, China
and Indonesia
) batch type vacuum fryers are mainly used for the production of fruit chips. However, these machines are only appropriate for relatively small production companies.
frying pan is installed in a stainless steel
vacuum tube. The infeed of the raw product is carried out through a rotary air lock
.
Depending on the application, the frying pan
itself is designed to meet the different product specifications. A transport belt takes the finished product out of the fryer and towards the outfeed system. A lock chamber at the exit of the vacuum tube prevents air from entering the vacuum zone, and a belt system takes the product from one zone to another.
The vacuum is created by vacuum pump
s, and the whole system is controlled by a programmable logic controller
.
In batch fryers, the frying oil has to be replaced quite often as it is sensitive to temperature changes. Continuously working vacuum fryers lead to a longer lifetime of the frying oil and therefore lower the production costs. Vacuum fryers can also reduce oil content in fried foods. The amount of reduced oil content, usually 1-3%, depends on the type of the vacuum fryer.
Vacuum
In everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...
chamber. It was originally developed for potato chip
Potato chip
Potato chips are thin slices of potato that are deep fried...
production.
Vacuum fryers are fit to process low-quality potato
Potato
The potato is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family . The word potato may refer to the plant itself as well as the edible tuber. In the region of the Andes, there are some other closely related cultivated potato species...
es that contain higher sugar levels than normal, as they frequently have to be processed in spring and early summer before the potatoes from the new harvest
Harvest
Harvest is the process of gathering mature crops from the fields. Reaping is the cutting of grain or pulse for harvest, typically using a scythe, sickle, or reaper...
become available. With vacuum frying it is easier to maintain natural colors and flavours of the finished product. Due to the lower temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
s applied (approx. 130°C), the formation of suspected carcinogen
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
acrylamide
Acrylamide
Acrylamide is a chemical compound with the chemical formula C3H5NO. Its IUPAC name is prop-2-enamide. It is a white odourless crystalline solid, soluble in water, ethanol, ether, and chloroform. Acrylamide is incompatible with acids, bases, oxidizing agents, iron, and iron salts...
is significantly lower than in standard atmospheric fryers, where the frying temperature is approx. 170°C. The fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...
absorption of the products is also reported to be lower than in atmospheric fryers. In South East Asia (mainly Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
, Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
and Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
) batch type vacuum fryers are mainly used for the production of fruit chips. However, these machines are only appropriate for relatively small production companies.
Continuously working vacuum fryers
For larger production quantities, continuously working vacuum fryers are available. In these installations, the vacuumVacuum
In everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...
frying pan is installed in a stainless steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
vacuum tube. The infeed of the raw product is carried out through a rotary air lock
Airlock
An airlock is a device which permits the passage of people and objects between a pressure vessel and its surroundings while minimizing the change of pressure in the vessel and loss of air from it...
.
Depending on the application, the frying pan
Frying pan
A frying pan, frypan, or skillet is a flat-bottomed pan used for frying, searing, and browning foods. It is typically in diameter with relatively low sides that flare outwards, a long handle, and no lid. Larger pans may have a small grab handle opposite the main handle...
itself is designed to meet the different product specifications. A transport belt takes the finished product out of the fryer and towards the outfeed system. A lock chamber at the exit of the vacuum tube prevents air from entering the vacuum zone, and a belt system takes the product from one zone to another.
The vacuum is created by vacuum pump
Vacuum pump
A vacuum pump is a device that removes gas molecules from a sealed volume in order to leave behind a partial vacuum. The first vacuum pump was invented in 1650 by Otto von Guericke.- Types :Pumps can be broadly categorized according to three techniques:...
s, and the whole system is controlled by a programmable logic controller
Programmable logic controller
A programmable logic controller or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines...
.
In batch fryers, the frying oil has to be replaced quite often as it is sensitive to temperature changes. Continuously working vacuum fryers lead to a longer lifetime of the frying oil and therefore lower the production costs. Vacuum fryers can also reduce oil content in fried foods. The amount of reduced oil content, usually 1-3%, depends on the type of the vacuum fryer.
External links
- Research project about vacuum frying in the Indonesia
- Report about a research project about vacuum frying in the US
- Vacuum fried fruit chips from Thailand
- Study about the reduction in acryamide content in potato chips by vacuum frying
- National Standard Maker & Top Manufacturer of Vacuum Fryer in Asia
- Manufacturer of Vacuum Fryers
- Report about vacuum fried snacks