Rancidification
198711
221885733
2008-06-26T15:03:10Z
Thijs!bot
1392310
robot Adding: [[pt:Rancificação]]
'''Rancidification''' is the decomposition of [[fat]]s, [[oil]]s and other [[lipid]]s by [[hydrolysis]] or [[oxidation]], or both. Hydrolysis will split [[fatty acid]] chains away from the [[glycerol]] backbone in [[glyceride]]s. These free fatty acids can then undergo further [[Fatty acid#Auto-oxidation and rancidity|auto-oxidation]]. Oxidation primarily occurs with [[unsaturated fat]]s by a [[free radical]]-mediated process. These chemical processes can generate highly reactive molecules in rancid foods and oils, which are responsible for producing unpleasant and noxious odors and flavors. These chemical processes may also destroy [[nutrient]]s in food. Under some conditions, rancidity, and the destruction of [[vitamin]]s, occurs very quickly.
[[Antioxidant]]s are often added to fat-containing foods in order to retard the development of rancidity due to oxidation. Natural anti-oxidants include [[flavonoid]]s, [[polyphenol]]s, [[ascorbic acid]] (vitamin C) and [[tocopherol]]s (vitamin E). Synthetic antioxidants include [[butylated hydroxyanisole]] (BHA), [[butylated hydroxytoluene]] (BHT), [[propyl 3,4,5-trihydroxybenzoate]] also known as [[propyl gallate]] and [[ethoxyquin]]. The natural antioxidants tend to be short-lived, so synthetic antioxidants are used when a longer shelf-life is preferred. The effectiveness of water-soluble antioxidants is limited in preventing direct oxidation within fats, but is valuable in intercepting free-[[Radical (chemistry)|radical]]s that travel through the watery parts of foods. A combination of water-soluble and fat-soluble antioxidants is ideal, usually in the ratio of fat to water.
In addition, rancidification can be decreased, but not completely eliminated, by storing fats and oils in a cool, dark place with little exposure to oxygen or free-radicals, since heat and light accelerate the rate of reaction of fats with oxygen.
==See also==
{{wiktionarypar|rancidification}}
*[[Food preservation]]
*[[Preservative]]
*[[Putrefaction]]
*[[fermentation (food)|Fermentation]]
[[Category:Food preservation]]
[[Category:Food science]]
[[cs:Žluknutí]]
[[da:Harskning]]
[[de:Ranzigwerden]]
[[fr:Rancissement]]
[[it:Irrancidimento]]
[[no:Harskning]]
[[pl:Jełczenie]]
[[pt:Rancificação]]
[[sk:Oxidácia tukov]]
[[sv:Härskning]]
[[zh:酸敗反應]]