Marshmallow, most commonly known as the pillowy white, sweet treat both kids and adults love, is also an herb that has anti-inflammatory, diuretic, emollient and laxative properties. It has been used to treat the common cold, cough, sore throat, bronchitis, Crohn's disease, ulcerative colitis, irritable bowel syndrome, stomach ulcers, asthma, indigestion and skin irritations.
Marshmallow probably came first into being as a medicinal substance, since the mucilaginous extracts come from the root of the marshmallow plant, Althaea officinalis, which were used as a remedy for sore throats. Concoctions of other parts of the marshmallow plant had medical purposes as well. The root has been used since Egyptian antiquity in a honey-sweetened confection useful in the treatment of sore throat.The later French version of the recipe, called pâte de guimauve (or "guimauve" for short), included an egg white meringue and was often flavored with rose water.
The use of marshmallow to make a sweet dates back to ancient Egypt, where the recipe called for extracting sap from the plant and mixing it with nuts and honey. Another pre-modern recipe uses the pith of the marshmallow plant, rather than the sap. The stem was peeled back to reveal the soft and spongy pith, which was boiled in sugar syrup and dried to produce a soft, chewy confection. Confectioners in early 19th century France made the innovation of whipping up the marshmallow sap and sweetening it, to make a confection similar to modern marshmallow. The confection was made locally, however, by the owners of small sweet shops. They would extract the sap from the mallow plant's root, and whip it themselves. The candy was very popular, but its manufacture was labour-intensive. In the late 19th century, French manufacturers thought of using egg whites or gelatin, combined with modified corn starch, to create the chewy base. This avoided the labour-intensive extraction process, but it did require industrial methods to combine the gelatin and corn starch in the right way.
Another milestone in the development of the modern marshmallow was the extrusion process by the American Alex Doumak in 1948. This invention allowed marshmallows to be manufactured in a fully automated way. The method produced the cylindrical shape that is now associated with marshmallows. The process involves running the ingredients through tubes and then extruding the finished product as a soft cylinder, which is then cut into sections and rolled in a mixture of finely powdered cornstarch and confectioner's sugar.
Marshmallows, like most sweets, are sweetened with sucrose. They are currently prepared by the aeration of mixtures of sucrose and proteins to a final density of about 0.5 g/ml. The viscosity of the mixture, owing to the proteins, gelatin or egg albumin, prevents collapse of the air-filled cells.