ALL ABOUT ZEIN
DESCRIPTION: ZEIN is the water-insoluble prolamine
from corn gluten, manufactured initially as a concentrated
powder. It is unique in its ability to form odorless, tasteless,
clear, hard and almost invisible edible films. Since ZEIN films
are completely safe to ingest, it is the perfect coating for foods
and pharmaceutical ingredients.
ZEIN is extracted from gluten by physical rather
than chemical
means and is, therefore, totally natural. It is a food ingredient,
not an additive. ZEIN is shown to be remarkably resistant to
bacterial attack, which frequently decomposes other proteinaceous
material. It seems to repel many insects such as the Indian Meal
Moth,
which often infests nut and grain products that are unprotected.
APPLICATIONS: ZEIN is presently used to coat
candy, flavors,
pharmaceutical tablets and ingredients which are encapsulated
in time-release, granulation and seeds. The coating forms used
are general film coating and enteric coating. In the food and
confection
industries, ZEIN is used for coating enriched rice, candies, such
as
chocolates and jelly beans, dried fruits, nuts, nut meats, and
also for
the encapsulation of flavors and sweeteners.
ZEIN can be combined with many other ingredients
to give different
coating qualities and with colors to give a wide range of color
coatings.
It is considered a better coating than shellac (confectioner’s
or
pharmaceutical glaze) because ZEIN coating solutions dry faster
offering extended shelf-life, particularly under high-humidity
and
high-heat conditions.
SAFETY: ZEIN was Generally Recognized As Safe
(G.R.A.S.) by
the USFDA in March, 1985. Evidence of its safety is the fact that
it has
been used for coating enriched rice for several decades. ZEIN
is now
in the USP XXIV NF XIX.
In replacing shellac with ZEIN, one would be replacing a highly
complex
organic acid insect exudate imported from southeast Asia with
a true
food ingredient.
LABELING: The name ZEIN may be used on product
labels, as well
as "Confectioner’s Glaze", "Vegetable Protein
Glaze", "Natural Glaze",
"Vegetable Protein Coating" and "Corn Protein Coating".
TECHNICAL: The quality of ZEIN that makes it
a prolamine, i.e., it's
insolubility in water, insolubility in anhydrous alcohol, and
solubility in a
mixture of the two, is considered due to the preponderance of
hydrophobic acids; leucine, proline and alanine. ZEIN’s
insolubility in
water is also due to the high proportion of hydrocarbon group
side
chains, and the high percentage of amide groups present with a
relatively low amount of free caroboxylic acid groups.
Another characteristic of ZEIN is its resistance to hydrolyzing
by very
dilute acids. Although there are 16 amino acids that have been
isolated
from ZEIN, the preponderant ones are
| Glutamic Acid & Glutamine |
20-22% |
Isoleucine |
3-7% |
| |
|
|
|
| Leucine |
17-20% |
Serine |
4-6% |
| |
|
|
|
| Proline |
5-9% |
Tyrosine |
3-5% |
| |
|
|
|
| Alanine |
8-10% |
Asparagine |
4-5% |
| |
|
|
|
| Phenylanlanine |
4-7% |
|
|
All other amino acids are present at less than 3%.
In whole corn, ZEIN occurs as a heterogenous mixture of
disulfide - linked aggregates. Commercial extraction results
in a product with molecular weights of 25-35,000. It was
discovered quite early that if the aqueous alcoholic solutions
of ZEIN were evaporated, a clear, hard film was formed, which,
among other things, was completely edible and had many
remarkable qualities. These films could be laid down as coatings
on food and pharmaceutical ingredients offering substantial
protection, as well as many other benefits, to the above materials.
HISTORY: ZEIN was first observed and described
by J. Gorham
in 1821 (J. Gorham Quart, J. Scientific Literature Arts II; pp
206-208, 1821). In 1897, T.B. Osborne (J.A.C.S. 19, pp 525-532,
1897) reported on ZEIN’s solubility in aqueous solutions
of the lower molecular weight
alcohols. These references are noted solely to show the length
of time
that ZEIN has been known. It has been commercially available since
1939.
From the 1930's through the early 1960's, ZEIN was used in a
myriad of industrial applications, ranging from coating paper
cups to lining soda bottle caps, to a special coating used in
photo films. ZEIN was also extensively used in the printing industry
as a safe, edible coating for inks.
STATUS: FREEMAN INDUSTRIES is the world’s
most foremost
researcher and extractor of ZEIN. This has assured both consistency
of quality production and the long lasting price stability of
ZEIN. Freeman Industries has been involved with ZEIN since 1965
and started their own production in 1975.
Our technical staff is ready to serve present and prospective
consumers
at any time.
ZEIN, as produced by Freeman Industries, is
Kosher. Its production
is certified by the Orthodox Union and each ZEIN label bears their
symbol.
