2. *SOY PROTEIN
*COTTON SEED PROTEINS
*RAPE SEED
• WHEAT GLUTEN
• CURN ZEIN
• KAFIRIN (GRAIN SORGHUM)
• OAT AVENIN
• RICE BRAIN PROTEIN (RBP)
• LUPIN
• PEANUT PROTEIN
3. Wheat gluten is composed of a
mixture of complete protein molecules
that can be separated in the glutenins
and gliadins on the basis of their
extractability in aqueous ethanol.
4. Wheat gluten is produced by washing wheat flour
extensively with water. The main part of the starch is
washed out and collect. Other water soluble substances
such as albumin proteins are also, at least to some
extent, removed. The final vital wheat gluten is rich in
protein, but also contains water, starch, fiber, fat and
ash.
Wheat protein consists of two types based on ethanol
solubility
Lower molar mass gyliadins are ethanol soluble
Higher molar mass glutenins are not soluble in ethanol.
In general, the gliadin/glutenin ratio is ~3/2
During extensive shearing or heating the protein polymerizes
which implies that gliadins with intramolecular sulfur – bonds
crosslinks intermolecular and hence produces large molecules.
5.
6.
7.
8. CORN ZEIN
Zein is a protein biopolymer that is renewable and can be
extracted from corn and corn coproducts.
As with gliadin, zein prolamine is insoluble in water, except at very low or
high pH, but is soluble in ethanol.
Corn zein consists of monomers and disulfide-linked oligomers. Because of
its lack of essential amino acids and its water insolubility the main interest
lately has been to use it as an industrial protein..
Zein has an amphiphilic character where the main chain has polar amino
acids but the side chains contain more than 50% nonpolar amino acids,
including leucine, isoleucine, valine, alanine, phenyl alanine and glycine.
The most common zein aminoacids are glutamic acid (glutamine) 21-26%,
leucine (20%), proline (10%) and alanine (10%)
This Protein can be divided in various ways, and one example shows two
major fractions; the α zein which includes ~80% of the available prolamine
and is defined as the fraction being soluble in 95% ethanol, and β-zein,
which is relatively unstable, but is soluble in water.
9.
10. α-Zein, which is the most abundant prolamin in
corn, is also the most widely used.
It was determined that α zein was the only zein
present in zein produced industrially (Wilson
1988).
This fraction has a unique amino acid sequence
and structure that allows for many industrial
uses.
α-Zein contains >50% nonpolar amino acid
residues and contains 9–10 tandem repeats of
helical segments of these nonpolar residues
linked by polar turns high in glutamine
11. Zein has had a variety of applications: plastics, coatings, inks,
chewing gum, adhesives, and fibers, etc.
Coating
Fiber and biodegradable films and plastics
Specific examples include hairs fixatives, , labels,
varnishes, microspheres, coatings on confectionery and nuts. IN
the 1970s almost 75% of the 500 tons of produced zein was
used to coat tablets.
For several applications the yellow colour of zein, due to
xanthophylls and carotenoids, is unattractive. Several ways of
reducing the colour have been tested and one way to get
relatively white zein is to start with waxy corn, which contains
less pigment and xanthophyll.
zein films have been explored for coatings in numerous food
applications.
12. Micro and nanoparticles of zein have been
studied as carriers of nonpolar drugs;
microspheres of zein have been produced
that contain Ciprofloxacin, an antibiotic
Recently, biomedical field and controlled
self-assembly has seen newer applications of
zein. Many of these new processes need
purified decolorized and deodorized zein
Dong et al (2003) grew human liver cells
(HL-7702) and mice fibroblast cells (NIH3T3)
on zein films and used polylactic acid (PLA)
and Corning microplates as control. Zein
films were produced from zein particles that
agglomerated upon drying.
13.
14. Zein is promising for tissue work because it has
high tensile strength to support the cells
. The zein film with the smallest zein particles
produced from the solvent (0.3% w/v) showed
the best results for proliferation of both cells
after three days
The ability to produce decolorized and
deodorized zein has allowed application of
extremely pure zein in the medical field for
tissue technology and cell growth
Nanoporous structures are potential scaffolds
for bone and tissue regeneration
15. KAFIRIN (GRAIN SORGHUM)
Kafirin is the prolamine of the staple crop sorghum
grown in the semi arid parts of South Africa.
It has properties similar to zein, but is more
hydrophobic and less digestable.
Films can be cast from aqueous ethanol (70 wt %)
solutions after heating to 700C.
An example of a plasticizer system for kafirin is a
mixture of glycerol, polyethylene glycol and lactic
acid.
16. Oats are considered the sixth most important crop in
the world. Avenin is the oat prolamine and is most
soluble in 45wt % ethanol, hence being more hydrophilic
than other prolamines.
It is worth pointing out that kafirin, zein and avenin are
considered safe with respect to celiac decease.
Glycerol – plasticized avenin films have been cast from
45 wt % ethanol solution by first heating the solution to
700C for 15 min.
OAT AVENIN
17. Unfractionated rice bran protein consists of a mixture of albumin,
globulin, prolamin and glutelin. Rice bran is produced in large
quantities as a co-product/by product from rice milling.
It has good nutritional quality and superior protein efficiency ratio.
Adebiyi et al. have cast films based on RBP at various pH,
plasticizer content and with or without thermal denaturation. It was
shown that the strongest films were made with heat treatment under
alkaline conditions. As with other proteins, casting should be carried
out some distance from the isoelectric point, which is low for RBP.
RICE BRAN PROTEIN
18. LUPIN
The seeds from lupin, a leguminous plant, can be
used to make films. The seeds are rich in protein, oil
and nonstarch polysaccharides and oligosaccharides
of the raffinose family.
The protein has a good balance of essential amino
acids.
A lupin seed protein isolate can be obtained by
essentially grinding the seeds, removing the fat,
extraction/precipitation and freeze-drying.
19. PEANUT PROTEIN
It is possible to cast bio-based films based on peanut proteins. Cast films
with peanut protein isolate and glycerol plasticizer from a basic 900C
solution. Whereas the peanut seed contains 45% lipid and 22~33% protein,
the peanut protein isolate contains significantly more protein and less fat
(protein content>95g/100g).
Films or solutions were exposed to different physical treatments (hear,
ultrasound, UV irradiation) or chemical treatments with acetic anhydride,
succinic anhydride, form-aldehyde or glutaraldehyde in order to improve the
properties of the final products.
It was shown that strength values in excess of 1 Mpa were obtained with
the heat treatment (especially at 700C), 24h UV exposure, ultrasonication
using a water bath or the addition of the aldehydes. It was shown that the
water vapor barrier was improved by heat treatment (60-900C) and the use of
the aldehydes. The oxygen barrier was improved using the heat treatment or
UV (ultrasound was not evaluated here.) Interestingly, the anhydrides did not
improve the mechanical or the barrier properties.
