Changes

Sour flavors are generally produced by [[acid]]s, and different acids produce different acidic flavors. Some familiar sour flavors are [[vinegar]] ([[acetic acid]]), sour [[milk]] (lactic acid), citrus [[fruit]] ([[citric acid]]), [[apple]]s (malic acid) and [[wine]] (tartaric acid) <ref name="Reineccius">Reineccuis, Gary. Flavor Chemistry and Technology. Taylor & Francis: 2006.</ref>.

Sour flavors are generally produced by [[acid]]s, and different acids produce different acidic flavors. Some familiar sour flavors are [[vinegar]] ([[acetic acid]]), sour [[milk]] (lactic acid), citrus [[fruit]] ([[citric acid]]), [[apple]]s (malic acid) and [[wine]] (tartaric acid) <ref name="Reineccius">Reineccuis, Gary. Flavor Chemistry and Technology. Taylor & Francis: 2006.</ref>.

[[Salt]]y flavors are most commonly associated with the mineral of the same name (sodium chloride), however most low [[molecular weight]] salts ([[ammonium]] [[chlorine|chloride]], [[potassium]] chloride, [[lithium]] chloride, [[sodium]] [[bromine|bromide]], ammonium bromide, sodium [[iodine|iodide]] and lithium iodide) have a salty taste <ref name="Pyke" />.

[[Salt]]y flavors are most commonly associated with the mineral of the same name (sodium chloride), however most low [[molecular weight]] salts ([[ammonium]] [[chlorine|chloride]], [[potassium]] chloride, [[lithium]] chloride, [[sodium]] [[bromine|bromide]], ammonium bromide, sodium [[iodine|iodide]] and lithium iodide) have a salty taste <ref name="Pyke">Pyke, Magnus. Synthetic Food. Spottiswoode, Ballanyne & Co: 1970.</ref>.

Less is known about sweet and bitter substances. There seems to be no relationship between [[organic chemistry|organic]] [[functional group]]s and sweet flavor (as almost every class of compound has a member which tastes sweet), yet at the same time the chemistry is very specific. For example, saccharine is 300 times sweeter than table [[sugar]] (sucrose), however if the [[hydrogen]] bonded to the [[nitrogen]] is replaced with a [[methyl]] group, all flavor sensation disappears <ref name="Pyke" />. Likewise, bitter sensations are difficult to classify, though many [[plant]]-derived [[molecule]]s which interact with the brain such as [[caffeine]] and [[nicotine]] <ref name="Reineccius" />, as well as large molecular weight ionic salts such as [[cesium]] chloride, [[rubidium]] bromide and potassium iodide <ref name="Pyke" /> produce bitter tastes.

Less is known about sweet and bitter substances. There seems to be no relationship between [[organic chemistry|organic]] [[functional group]]s and sweet flavor (as almost every class of compound has a member which tastes sweet), yet at the same time the chemistry is very specific. For example, saccharine is 300 times sweeter than table [[sugar]] (sucrose), however if the [[hydrogen]] bonded to the [[nitrogen]] is replaced with a [[methyl]] group, all flavor sensation disappears <ref name="Pyke" />. Likewise, bitter sensations are difficult to classify, though many [[plant]]-derived [[molecule]]s which interact with the brain such as [[caffeine]] and [[nicotine]] <ref name="Reineccius" />, as well as large molecular weight ionic salts such as [[cesium]] chloride, [[rubidium]] bromide and potassium iodide <ref name="Pyke" /> produce bitter tastes.