As we said earlier, pectin is found in the middle
lamella, and acts as an intercellular cement holding adjacent cells together. In addition to its use in jellies, pectin is also a common
ingredient in pharmaceuticals, cosmetics, lotions, and adhesives. Its also used to
thicken ketchup and salad dressings, to help retain moisture in baked goods, and as an
emulsifier in dairy products. And its even been used in the treatment of burns.
Natural gums are found in some woody tissues and seeds.
They function in the plant to seal wounds and prevent infection by microorganisms. Similar
to pectins, they are commonly used to thicken and stabilize food products.
Guar gum is obtained from guar, a legume similar to its
relative, the soybean. Guar gum is derived from the seed; its high viscosity and
stabilizing qualities have made it useful in the manufacture of cosmetics, drugs, papers,
and some foods. Agar (also called agar-agar) is another jellylike substance. Most familiar
as a culture medium in biology labs, it is also used as a stabilizer in ice creams sauces,
and other foods. It is extracted from several species of seaweeds.
Gums are also used as sizing agents in textile production
to stiffen fibers and facilitate weaving, and in paper production.