Gelatin is probably one of the best known additives outside the
food industry. Its discovery dates back to the Egyptians, who used
it to make glue. Since then, its use has obviously become greatly
diversified!

Gelatin is naturally formed when meat, bones or skin are slowly
boiled to make a stock or stew. Once cooled, the mixture forms
a jelly. Gelatin was known and used in cooking well before the
product was marketed at the end of the 19th century, when an
American named Charles Knox introduced it on the U.S. market
in the form of a powder.

Unlike other additives presented in this book, gelatin is of animal
origin. Its structure is therefore a blend of amino acids, the
components of proteins. Gelatin is derived from collagen found in
the skin and bones of beef, pork, fish or poultry. Once these parts
are ground, an acid or alkaline treatment is applied to them for
days, or even months, after which they are boiled and cleared of
impurities through filtration. A concentration of the solution and a
high temperature treatment are applied before cooling and drying.
On the market, gelatin comes in powder form, flakes, sheets or
granules. The origin of the raw material and the processing obviously
affect the gel’s final strength.

During cooling, chains of amino acids form helices that trap water
in a structure resembling a fishing net. Due to gelatin’s properties,
it can be added to food as a gelling agent, stabilizer, emulsifier and
crystal inhibitor. The gel formed is thermoreversible and melts
at about body temperature, which creates a melt-in-the-mouth
sensation.

The main criticism of gelatin concerns its animal origin and the fear
that it may contain contaminants or unwanted bacteria. However,
gelatin purity regulations are very strict and only animals that
are tested and approved for human consumption are used in the
product. In the industry, gelatin is considered an ingredient rather
than an additive and no consumption limits have been set.