Derived from cellulose, a structural component of plant cells,
methylcellulose was first introduced at the end of the 1930s in
Germany, then a few years later in the United States. This extract
from wood or cotton has several desirable characteristics such as
film formation, water retention and the ability to form a gel with
heat, which will melt upon cooling. It also acts as a thickening and
binding agent.

Extraction of methylcellulose first requires mixing with an alkali,
followed by the addition of methyl chloride, which transfers its
methyl group to the molecule. The resulting pulp is then rinsed
and filtered at a high temperature, so as to avoid gelling the
product. Other cellulose by-products are also available on the
market, such as hydroxypropyl methylcellulose (HPMC) and super
methylcellulose (SMC).

Vegetable gum is soluble in cold water and forms a soft to firm
elastic gel at temperatures around 122°F (50°C), although certain
classes of the product can form a gel at about 86°F (30°C). When
the temperature drops, the gel then returns to its original form as
a solution. By heating, the molecule gets rid of its bonds with the
water and forms new ones with its own kind, thus creating the
structure needed for a gel. However, the addition of salt or sugar
decreases the temperature at which the gel forms. The molecule
also has hydrophobic characteristics and is able to trap air, which
makes it the emulsifier of choice.

Methylcellulose is useful in the industry due to its stability during
cooking and its ability to trap moisture and air, which increases the
volume of dough and frozen dairy products. When added to French
onions, it preserves the onion’s shape and texture during cooking
and reduces oil absorption by forming a film.

The ability of methylcellulose to preserve the shape of products
makes it a popular ingredient in waffles and soy-based imitation
meat. The presence of methylcellulose causes the formation of
a gel during cooking, preventing the product from disintegrating,
since it will be trapped by the gel. Once the food is cooled and the
methylcellulose has returned to its soluble form, the gel disappears.
No one will be any the wiser!