Deep frying
[3] The term "deep frying" and many modern deep-fried foods were not invented until the 19th century, but the practice has been around for millennia.
Deep frying is popular worldwide, with deep-fried foods accounting for a large portion of global caloric consumption.
][better source needed] The, 5th century CE, Roman cookbook Apicius offers a recipe for deep fried chicken in a cream sauce "Pullus leucozomus".
[20] While most foods need batter coatings for protection, it is not as necessary for cooked noodles and potatoes because their high starch content enables them to hold more moisture and not shrink.
[20][24] An informal test for a temperature close to this range involves adding a tiny amount of flour into the oil and watching to see if it sizzles without immediately burning.
A second test involves adding one piece of food to deep fry and watching it sink somewhat and rise back up.
Less common deep-fried foods include maple leaves,[33] peanut butter and jelly sandwiches,[34] pizza,[35] Mars and Snickers bars.
[39] In East Africa deep fried food is common, cooked in cast iron or earthenware pots.
Japanese tempura is a popular deep-fried food[42] that generally consists of battered and fried seafood and vegetables.
Japanese deep-fried dishes, or Agemono, include other styles besides tempura, such as Karaage, Korokke, Kushikatsu, and Tonkatsu.
Some popular deep fried foods include ayam goreng (chicken), pecel lele (catfish), pempek (fishcake) and tempeh.
[51] Belgian tradition requires French fries to be deep-fried in filtered fat of cattle, locally called blanc de boeuf or ossewit.
[55] Artists such as Henry Hargreaves have deep-fried replicas of electronic items such as iPads, Game Boys, and laptops.
[57] Notable past winners have included fried Coke and deep-fried butter, both invented by Abel Gonzales.
Deep fat frying involves heating oil to temperatures in excess of 180 °C in the presence of moisture and air.
These conditions can induce a series of complex chemical reactions which may impact the quality of both the food and the oil it is cooked in.
Examples of different chemical reactions include the production of free radicals, oxidation, hydrolysis, isomerization and polymerization.
The exact reactions are dependent upon factors such as the oil type, frying conditions, and food being cooked.
When frying, water can attack the ester linkage of triacylglycerols, resulting in mono- and diglycerols, glycerol, and free fatty acids (a type of hydrolysis reaction).
[62] Overheating or over-using the frying oil leads to formation of rancid-tasting products of oxidation, polymerization, and other deleterious, unintended or even toxic compounds[63] such as acrylamide (from starchy foods).
[64] Deep-frying under vacuum helps to significantly reduce acrylamide formation,[65] but this process is not widely used in the food industry due to the high investment cost involved.
Other means of extinguishing an oil fire include application of dry powder (e.g., baking soda, salt)[72] or firefighting foam.
[79] Potatoes that are stored in artificially humidified warehouses contain more water, which makes the time required to deep fry them into chips longer.
This increases the carbon dioxide footprint of commercially producing chips because more energy is required for frying over a longer time.
Consumption of large amounts of saturated and trans fats has been linked to a higher risk for some cancers.
[81] Eating deep-fried foods has also been linked to higher cholesterol levels, obesity, heart attacks, and diabetes.
[83] Additionally, fat degradation processes (lipid peroxidation) during deep frying results in the loss of nutritional value in deep-fried foods.
[20] However, excessive use of the same oil can cause it to break down and release compounds into the food that may be carcinogenic, affect liver health, or influence the body's ability to absorb vitamins.
