Editing Emulsion (section)

==Emulsifiers==
An '''emulsifier''' is a substance that stabilizes an emulsion by reducing the oil-water [[interface tension]]. Emulsifiers are a part of a broader group of compounds known as [[surfactant]]s, or "surface-active agents".<ref>{{cite web |title=Emulsions: making oil and water mix |url=https://www.aocs.org/stay-informed/inform-magazine/featured-articles/emulsions-making-oil-and-water-mix-april-2014?SSO=True |publisher=www.aocs.org |access-date=1 January 2021}}</ref> Surfactants are compounds that are typically [[Amphiphile|amphiphilic]], meaning they have a polar or [[Hydrophile|hydrophilic]] (i.e., water-soluble) part and a non-polar (i.e., hydrophobic or [[Lipophilicity|lipophilic]]) part. Emulsifiers that are more soluble in water (and, conversely, less soluble in oil) will generally form oil-in-water emulsions, while emulsifiers that are more soluble in oil will form water-in-oil emulsions.<ref>Cassidy, L. (n.d.). Emulsions: Making oil and water mix. Retrieved from https://www.aocs.org/stay-informed/inform-magazine/featured-articles/emulsions-making-oil-and-water-mix-april-2014</ref>

Examples of food emulsifiers are:

* [[Egg yolk]]&nbsp;– in which the main emulsifying and thickening agent is [[lecithin]].
* [[Mustard seed|Mustard]]<ref>{{cite magazine|author=Riva Pomerantz|date=Nov 15, 2017|title=KOSHER IN THE LAB|magazine=[[Ami (magazine)|Ami]]|issue=342}}</ref>&nbsp;– where a variety of chemicals in the [[mucilage]] surrounding the seed hull act as emulsifiers
* [[Soy lecithin]] is another emulsifier and thickener
* [[Pickering emulsion|Pickering stabilization]]&nbsp;– uses particles under certain circumstances
* [[Mono- and diglycerides of fatty acids|Mono- and diglycerides]] – a common emulsifier found in many food products (coffee creamers, ice creams, spreads, breads, cakes)
* [[Sodium stearoyl lactylate]]
* [[DATEM]] (diacetyl tartaric acid esters of mono- and diglycerides)&nbsp;– an emulsifier used primarily in baking 
* [[Protein]]s – those with both hydrophilic and hydrophobic regions, e.g. sodium [[casein]]ate. [[Processed cheese]] use acids to [[chelate]] away calcium, which allows cheese casein to work as an emulsifier.

In food emulsions, the type of emulsifier greatly affects how emulsions are structured in the stomach and how accessible the oil is for gastric [[lipases]], thereby influencing how fast emulsions are digested and trigger a [[satiety]] inducing [[hormone]] response.<ref>{{cite journal |last1=Bertsch |first1=Pascal |last2=Steingoetter |first2=Andreas |last3=Arnold |first3=Myrtha |last4=Scheuble |first4=Nathalie |last5=Bergfreund |first5=Jotam |last6=Fedele |first6=Shahana |last7=Liu |first7=Dian |last8=Parker |first8=Helen L. |last9=Langhans |first9=Wolfgang |last10=Rehfeld |first10=Jens F. |last11=Fischer |first11=Peter |title=Lipid emulsion interfacial design modulates human in vivo digestion and satiation hormone response |journal=Food & Function |date=30 August 2022 |volume=13 |issue=17 |pages=9010–9020 |doi=10.1039/D2FO01247B |pmid=35942900 |pmc=9426722 |language=en |issn=2042-650X}}</ref>

[[Detergent]]s are another class of surfactant, and will interact physically with both [[cooking oil|oil]] and [[water]], thus stabilizing the interface between the oil and water droplets in suspension. This principle is exploited in [[soap]], to remove [[yellow grease|grease]] for the purpose of [[cleaning agent|cleaning]]. Many different emulsifiers are used in [[pharmacy]] to prepare emulsions such as [[cream (pharmaceutical)|creams]] and [[lotion]]s. Common examples include [[emulsifying wax]], [[polysorbate 20]], and [[ceteareth|ceteareth 20]].<ref>{{cite web|url=http://www.teachsoap.com/emulsifywax.html|title=Using Emulsifying Wax|access-date=2008-07-22|author=Anne-Marie Faiola|date=2008-05-21|website=TeachSoap.com}}</ref>

Sometimes the inner phase itself can act as an emulsifier, and the result is a nanoemulsion, where the inner state disperses into "[[nano-]]size" droplets within the outer phase. A well-known example of this phenomenon, the "[[ouzo effect]]", happens when water is poured into a strong alcoholic [[anise]]-based beverage, such as [[ouzo]], [[pastis]], [[absinthe]], [[Arak (distilled beverage)|arak]], or [[Rakı|raki]]. The anisolic compounds, which are soluble in [[ethanol]], then form nano-size droplets and emulsify within the water. The resulting color of the drink is opaque and milky white.