Editing Marshmallow (section)

==== Gelatin ====
[[Gelatin]] is the aerator most often used in the production of marshmallows. It is made up of [[collagen]], a structural protein derived from animal skin, connective tissue, and bones. Not only can it stabilize foams, like albumen, but when combined with water it forms a thermally-reversible gel. This means that gelatin can [[melting|melt]], then reset due to its sensitivity to temperature. The melting point of gelatin gel is around {{convert|95|F|C}}, which is just below [[normal body temperature]] (around {{convert|97|F|C}}). This is what contributes to the "melt-in-your-mouth" sensation when a marshmallow is consumed—it actually starts to melt when it touches the tongue.<ref name="UCLA" />

During preparation, the temperature needs to be just above the melting point of the gelatin, so that as soon as it is formed it cools quickly, and the gelatin sets, retaining the desired shape. If the marshmallow rope mixture exiting the extruder during processing is too warm, the marshmallow starts to flow before the gelatin sets. Instead of a round marshmallow, it takes on a more oval form. Excessive heat can also degrade, or break down, the gelatin itself. Therefore, when marshmallows are being produced at home or by artisan candy makers, the gelatin is added after the syrup has been heated and cooled down.

In commercial operations, the gelatin is simply cooked with the sugar syrup, rather than being added later after the syrup has cooled. In this case, kinetics play an important role, with both time and temperature factoring in. If the gelatin was added at the beginning of a batch that was then cooked to 112–116&nbsp;°C in 20–30 minutes, a significant amount of gelatin would break down. The marshmallow would have reduced springiness from that loss of gelatin. But since the time the syrup spends at elevated temperature in modern cookers is so short, there is little to no degradation of the gelatin.<ref name="Hartel">{{Cite book|title=Candy Bites: The Science of Sweets|last1=Hartel|first1=Richard|last2=Hartel|first2=AnnaKate|publisher=Copernicus|year=2014|isbn=978-1-4614-9382-2|location=New York|pages=199–202}}</ref>

In terms of texture, and mouth-feel, gelatin makes marshmallows chewy by forming a tangled 3-D network of polymer chains.  Once gelatin is dissolved in warm water (dubbed the "blooming stage"), it forms a [[Dispersion (chemistry)|dispersion]], which results in{{how|date=June 2021}} a [[cross-link]]ing of its helix-shaped chains.  The linkages in the gelatin protein network trap air in the marshmallow mixture and immobilize the water molecules in the network. The result is the well-known spongy structure of marshmallows. This is why the omission of gelatin from a marshmallow recipe results in [[marshmallow creme]], since there is no gelatin network to trap the water and air bubbles.<ref name="UCLA" />