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Whey protein

Authors:
  • Shri. Sant Gajanan Maharaj College of Pharmacy Buldana
ISSN 2249-5975
Vol 1 / Issue 2 / Jul 2011
www.scholarsjournal.in
Publication of Society of United Life Sciences, India
Scholars'
Research Journal
Scholars' Research Journal / Jul-Dec 2011 / Vol 1 / Issue 2 69
Review Article
Whey protein
Hemant H Gangurde, Mayur A Chordiya, Pooja S Patil, Nayana S Baste
Department of Pharmaceutics, SNJB’s S.S.D.J., College of Pharmacy, Neminagar, Chandwad, Nasik, Maharashtra, India
Abstract
Whey is one of the two proteins in cow’s milk, making approximately 20%, and casein is the other protein that forms
approximately 80% of the total protein content. Whey proteins refer to a group of individual proteins or fractions that
separate out from the casein during cheese making. These fractions are puried to different concentrations, depending
on the end composition desired, and can vary in their content of protein, lactose, carbohydrates, immunoglobulin,
minerals, and fat. The most common forms of whey protein used in high protein bars, beverages, and supplements
are the concentrate (WPC) or the isolate (WPI). Protein Digestibility Corrected Amino Acid Score (PDCAAS) is a new
system that determines the protein quality and is utilized to establish the percent daily value for the nutrients on food
labels. Whey protein is a complete, high-quality protein with a rich amino acid (AA) prole. It contains the full spectrum
of AAs including essential AAs (EAAs) and branched-chain AAs (BCAAs) which are important in tissue growth and
repair. Leucine is a key BCAA in protein synthesis and has recently been identied as playing a critical role in insulin,
muscle building, and glucose metabolism. The EAAs and BCAAs in whey protein are present in higher concentrations
compared with other proteins such as soy, meat, and wheat; they are also efciently absorbed and utilized. Whey protein
also has some important benets like it reduces the symptoms of chronic fatigue and its major use is in the HIV and viral
infections as it increases the immunity. The review discusses the history, types, forms, side effects and applications of
whey protein in human health.
Key Words: Branched chain amino acids, chronic fatigue syndrome, protein digestibility corrected amino acid score, whey
protein
INTRODUCTION
Proteins are organic compounds made of amino
acids arranged in a linear chain and folded into a
globular form. They are also known as polypeptides.
The amino acids in a polymer are joined together
by the peptide bonds between the carboxyl and
amino groups of adjacent amino acid residues. The
sequence of amino acids in a protein is dened by
the sequence of a gene, which is encoded in the
genetic code. There are 20 common amino acids.
Amino acids share a common structure except for
one chemical group (R, side chain) attached to the
central carbon atom. The 20 different R groups give
the amino acids their individual characteristics.
Amino acids join up to make peptide chain. The
words peptide and protein actually refer to the
same structure; however, peptide is generally used
for shorter chains of amino acids and protein for
longer chains. Proteins made up of more than one
polypeptide chain, as many of the large ones are, are
called oligomeric.[1]
Proteins can be classied based upon
Structure ,enzymes, receptor action and functions
[Table 1]. Proteins are derived from various sources
such as milk, meat, egg, soy, wheat, etc [Table 2].
Milk has two proteins: casein and whey protein.
Whey protein is more soluble than casein and also has
a higher quality rating. Whey is highly bioavailable
and boasts having the highest biological value (BV)
of any protein source. Therefore, a whey product may
be an excellent choice for those looking for a protein
product that can be readily used by the body to build
mass. Casein makes up the other 80% of protein in
milk and is often considered to be the slowest acting
form of protein because it takes longer than whey or
soy protein to digest. Eggs are often considered to be
one of the healthiest forms of protein because they
contain virtually all of the amino acids used in the
human body. Since egg protein contains no dairy, it is
Address for correspondence: Mr. Hemant H Gangurde, Department of Pharmaceutics, SNJB’s S.S.D.J. College of Pharmacy, Neminagar, Chandwad –
423 101, Nasik, Maharashtra, India. E-mail: hhgangurde@gmail.com
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DOI: 10.4103/2249-5975.99663
Gangurde, et al.: Whey protein
70 Scholars' Research Journal / Jul-Dec 2011 / Vol 1 / Issue 2
often used by those who are allergic to lactose, even
though low lactose whey protein is available.
Soy protein is a healthy and vegan appropriate way of
getting protein. It is comparable in quality to casein,
but digests within 2–4 hours of consumption, making
it an ideal addition to meals. Soy protein is known to
be a good antioxidant and soy products often contain
other healthy vitamins, but recent medical debates
have questioned the possibility of several downsides
to ingesting large amounts of soy.
Meat protein is a general classication for all forms
of protein found in meat. These types of protein are
usually slow-burning and incomplete, but they offer a
good source of nutrition if ingested along with other
forms of protein. Turkey and salmon are two of the
best forms of lean protein to be found in meat, as they
have lower fat contents and more balanced forms of
pro types of whey protein.[2]
Whey Protein
Whey protein is a high-quality protein powder
from cow’s milk. Milk has two proteins: casein
(approximately 80%) and whey protein (approximately
20%) [Figure 1a-b].[5,6] Whey contains less than 1%
proteins comprising mainly β-lactoglobulin (β-LG),
α-lactalbumin (α-LA), bovine serum albumin (BSA),
immunoglobulins and proteose peptone, as well as
several minor proteins including lactoferrin, lactollin,
glycoproteins, lactoperoxidase and transferrin.[7] Whey
proteins are the proteins remaining soluble at pH 4.6
and 20°C after the removal of caseins from milk. Two
primary types of whey are available as whey protein
sources. Acid whey is produced by the generation or
direct addition of acid and results in the precipitation
of caseins. Sweet whey comes from rennet coagulated
cheese when caseins are removed.[8] Advances in
processing technologies have enabled the purication
and separation of whey proteins which are sold
as concentrate (WPC) or isolate (WPI) containing
35–80% and >90% proteins, respectively.[9] The
production of WPC begins with a clarication step
where centrifugation removes small cheese and casein
particles. Then, ultraltration, a physicochemical
separation technique in which a pressurized solution
ows over a porous membrane, allows the selective
separation of whey proteins from lactose, salts, and
water under mild conditions of temperature and pH.
Dial ltration can be applied to further increase the
protein purity by continuously adding water to the
ultra ltration retentive stream. Finally, spray drying
is used to yield a product with greater than 95% total
solids. On the other hand, ion exchange fractionation
processes are used for the manufacture of WPI. Whey
proteins have a net positive charge at pH values lower
than their isoelectric point (pH 5.2) and behave as
cations that can be absorbed on cation exchangers. At
pH values above their isoelectric point, whey proteins
Solid
13%
Water
87%
Whey
protein
20%
Casein80%
Figure 1: (a) Composition of whole milk. (b) Composition of whey and
casein protein in milk[5]
Table 1: Types of protein depending on their
function[1]
Protein types Function Examples
Structural Give shape and size to
the cell or organelles
Actin, tubulin
Enzymes Catalyze biological
reaction
Tyrosine adenylate
cyclase
Receptors Bind to other molecule
and transmit signals
Glutamate R.,
steroid R.
Other functional
proteins
Have specic functions Antibodies, nuclear
factor, neuropeptides
Table 2: Chemical constituent of various proteins and their biological value[3,4]
Protein
type
Protein
digestibility
corrected amino
acid source
Amino
acid
Protein
efciency
ratio
(PER)
Biological
value
(BV)
Protein
digestibility %
(PD)
Whey protein 1.00 1.14 3.2 100 99
Whole egg 1.00 1.21 3.8 88-100 98
Casein 1.00 1.00 2.5 80 99
Soy protein
concentration
1.00 0.99 2.2 74 95
Beef protein 0.92 0.94 2.9 80 98
Wheat gluten 0.25 0.47 NA 54 91
ab
Gangurde, et al.: Whey protein
Scholars' Research Journal / Jul-Dec 2011 / Vol 1 / Issue 2 71
have a net negative charge and behave as anions that
can be absorbed on anion exchangers. Once proteins
are absorbed onto the resins, a change in the pH of
the mobile phase is used to detach them, followed
by ultraltration, dial ltration, and drying. WPIs are
characterized by high protein and low lactose and
lipid concentration.[10]
Composition
Whey protein is the collection of globular proteins
isolated from whey, a by-product of cheese
manufactured from cow’s milk. It is typically a
mixture of β-LG (~65%), α-LA (~25%), and serum
albumin (~8%), which are soluble in their native
forms, independent of pH. The protein fraction
in whey (approximately 10% of the total dry
solids within whey) comprises four major protein
fractions and six minor protein fractions. The major
protein fractions in whey are β-LG, α-LA, BSA, and
immunoglobulin. The above composition has been
summarized in Table 3.[11]
History
Whey is now used in various products like infant
formulas, food supplements, sport bars, and beverages
to meet a variety of health goals for people of all ages.
It has been proven that the intake of whey in the form
of liquid was started by the Greeks. Around 2500
years ago, Hippocrates recommended some drinks to
enhance the immune system, power, and the muscle
growth rate of the body. These old time energy
drinks were known as serums. Serums were rich in
lactose, minerals and fast absorbing proteins, which
made them effective in enhancing the performance
of the body. In the late 16th century, Switzerland was
the place where the importance of whey protein was
rediscovered. It was noticed by the farmers that the
pigs which slopped on whey developed faster than
the pigs which slopped on something else. So, the
farmers started drinking the whey themselves. When
they noticed improvement in their health, the word
spread quickly throughout the land. Whey was an
important by-product of cheese production from the
rst commercial cheese factory in the city of New
York. This factory generated large amount of whey
which was very difcult to dispose. Due to this, the
cheese makers used to dump large amount of whey
into lakes and rivers or they used it for irrigating
crops. Farmers soon realized that it was not the best
use of the whey which was produced, and hence they
started mixing the liquid whey with barley or grain
to produce high-protein animal feed. In the past 20
years, whey protein has changed from being a waste
product of cheese making to a highly valued product
rich in nutritional and functional properties.[14,15]
Production
Whey is left over when milk coagulates and contains
everything that is soluble from milk. It is a 5%
solution of lactose in water, with some minerals and
lactalbumin. It is removed after cheese is processed.
The fat is removed and then is processed for
human foods.[5] Processing can be done by simple
drying, or the protein content can be increased by
removing lipids and other non-protein materials
[Figures 2 and 3].[16] For example, spray drying after
membrane ltration separates the proteins from
whey.[6]
Whey can be denatured by heat. High heat (such
as the sustained high temperatures above 72°C
associated with the pasteurization process) denatures
whey proteins. While native whey protein does not
aggregate upon renneting or acidication of milk,
denaturing the whey protein triggers hydrophobic
interactions with other proteins and the formation of
protein gel.[16] Heat-denatured whey can still cause
allergies in some people.[17]
Gelation is an important functional property of
whey proteins. Gelation is caused by the action of
heat, pressure, and divalent cations. Whey protein
solutions are prepared by dissolution of the powder in
deionized distilled water and stirring with a magnetic
stirrer for 90 min at room temperature in beakers at
a concentration of 10%. The pH of the solutions is
adjusted using 1 N HCl and 1 N NaOH. Beakers are
Figure 2: Extraction process of whey protein
Table 3: Chemical constituents of whey
protein[12,13]
Chemical constituent Percentage
α-Lactalbumin 11.3–16.5
b- Lactalbumin Lactoglobulin 37.9–49.0
IgG 5.0–8.0
Glycomacropeptides 15.0–20.0
Lactoferrin 1.3–1.8
Bovine serum albumin 3.0–5.0
Gangurde, et al.: Whey protein
72 Scholars' Research Journal / Jul-Dec 2011 / Vol 1 / Issue 2
placed in a water bath heated at 80°C for 30 min. After
the heat treatment, the solutions are rapidly cooled
to 10°C in an ice bath and stored in a refrigerator
overnight. Gels are placed at room temperature 2
hours before texture analysis. The whey proteins are
compact globular proteins with a relatively uniform
distribution of a chain of polar, non-polar, uncharged
and charged remains of amino acids.[18] Whey can be
further processed into spray-dried products like, for
instance, WPCs, WPIs or whey protein hydrolysates
(WPHs).[5]
This can further be proven using the Protein
Digestibility Corrected Amino Acid Score (PDCAAS)
which is a new system that determines the protein
quality and is utilized to establish the percent daily
value for the nutrients on food labels. The maximum
PDCAAS is 1.00, and whey protein has a PDCAAS
of 0.99–1.00. Whey protein contains little to no fat,
lactose, or cholesterol, and is a rich source of essential
amino acids.[19] PDCAAS values changes with the
change in type of protein shown in Table 4.
Amino Acids in Whey Protein
Whey protein is loaded with the essential and non-
essential amino acids with few carbohydrates and
little fat content. It contains the amino acid cysteine
which can be used to make glutathione (GSH).
However, this amino acid is not essential for the
synthesis of GSH and some studies have suggested
that the amount of cysteine in the diet may have little
effect on GSH synthesis. However, another study
suggested that large amounts of whey protein can
increase cellular GSH levels. GSH is an antioxidant
that defends the body against free radical damage and
some toxins, and studies in animals have suggested
that milk proteins might reduce the risk of cancer.[20,21]
Major forms of whey protein
Whey protein concentrate
Whey protein isolate
Hydrolyzed whey protein
Whey protein concentrates
WPCs are available in various protein concentration
levels such as 34% (WPC34), 50% (WPC50), or 80%
(WPC80). Concentrates contain a low level of fat
and cholesterol but, in general, have higher levels of
bioactive compounds, and carbohydrates in the form
of lactose. 70–80% protein content is more available as
protein powder supplement.[22,23]
Whey protein isolate
It is the purest form of whey protein and contains
90% or greater protein with minimal lactose (<1%)
and virtually no fat and is of high cost. Isolates are
processed to remove the fat and lactose, but are
usually lower in bioactive compounds.[23]
Hydrolyzed whey protein
Hydrolysates are predigested, partially hydrolyzed
whey proteins that, as a consequence, are more
easily absorbed, but their cost is generally higher.
Highly hydrolyzed whey may be less allergenic than
other forms of whey. They are very bitter in taste.
Hydrolysis process breaks down protein chains into
small fractions called peptides [Table 5].[6]
Whey Protein
Isolation of whey protein
WPI is generally the highest quality of whey
supplement, and therefore usually the most
expensive. These products “isolate” the whey protein
by going through the most advanced ltering process
to remove carbohydrates and fats. Thus, they have the
Dairy Milk
Curds Whey
Cheese Casein
Protein
Whey Protien
Isolate
(WPI)
Hydrolysed
Whey Protein
Isolate()HWPI
Whey Protein
Blend(WPC +
WPI)
Whey Protein
Blend(WPC +
WPI)
Whey Protein
Concentrate
(WPC)
Figure 3: Steps involved in manufacturing whey protein
Table 4: PDCAAS of various key proteins
Protein source PDCAAS
Whey protein 1.14
Casein 1.0
Milk protein isolate 1.0
Soy protein isolate 1.0
Egg white powder 1.0
Ground beef 1.0
Canned lentils 0.52
Peanut meal 0.52
Wheat gluten 0.25
Gangurde, et al.: Whey protein
Scholars' Research Journal / Jul-Dec 2011 / Vol 1 / Issue 2 73
highest percentage of protein compared to other whey
products. The whey isolate supplements are very
quickly absorbed and are therefore very fast-acting.
WPCs are products that do not go through such an
advanced ltering process as the whey isolate. Hence,
they generally contain about 10–15% less protein and
most likely include some fats and carbs. Some WPC
products also have some whey isolate blended in.[25,26]
WPI has been further differentiated into three types:
• Micro-ltered undenatured isolate
• Undenatured WPI
• WPI bars
Pharmacology of Whey Protein
A protein may have all of the amino acids required,
but this becomes immaterial if the protein cannot be
absorbed easily. BV is a percentage score showing
how much of the protein is absorbed by the body.
Whey protein, along with whole egg, has a perfect
score of 100. In addition to the complete absorption
level, it is important that the protein be absorbed as
fast as possible to aid recovery after training. Whey
protein is digested exceptionally quickly, which
makes it ideal as a post-workout liquid meal. The
biggest of an issue this is for you, the more important
the purity of the protein. Again, WI ranks above any
other protein in this area. On a more practical level,
different proteins have a different taste, but many
people quite enjoy the mild, milky taste of whey
protein isolate.[5]
Benefits of Whey Protein
Whey protein contains the highest concentration (23–
25%) of branched-chain amino acids (BCAAs) of any
single protein source. This BCAA content is important
to athletes because BCAAs are an integral part of
muscle metabolism and are the rst aminos sacriced
during intense exercise and muscle catabolism
(breakdown).[6,27]
Whey also has the ability to enhance endogenous
GSH production. GSH is the body’s most powerful
naturally occurring antioxidant and also plays a role
in immune system support.
Whey protein contains quadrapeptides, which have
been shown to have opioid effects. This is another
powerful functional property that may help decrease
the sensation of muscle soreness following intense
weight training.
Due to its excellent amino acid prole, solubility
and digestibility, whey has a very high BV. BV is a
measure of how well a protein is utilized by the body.
One of the more interesting functional properties
of whey protein is its ability to help stimulate IGF4
production.
Whey has been shown to reduce cholesterol by
inhibiting low-density lipoprotein (LDL) production.
Whey protein has antibacterial, anti-viral activity; also,
it reduces liver damage, improves immune system
function, digestive function, and blood pressure, and
reduces gastric mucosal injury.
Whey Versus Soy Protein
Both soy protein and whey protein are helpful in
building body muscle. Soy proteins and whey proteins
are competitors. People, unknown about muscle
building supplements, have wondered which protein
is better for their individual workout needs and what
the difference is between the two. Soy protein is
taken from soybeans and contains a high amount of
amino acids. It has been found to lower cholesterol,
Table 5: Uses of different types of whey protein (percentages by weight)[24]
Product Protein
concentration
Lactose
(%)
Fat Applications
Whey powder 11–14.5% 63–75 1–1.5% Used in breads, bakery and snack items and dairy
foods
Whey protein
concentrate
25–89% (most
commonly available as
80%)
4–52 1–9% (as protein
concentration increases, fat,
lactose and mineral content
decreases)
The most common and affordable form of whey.
Used in protein beverages and bars, bakery and
confectionary products, dairy foods and other
nutritional food products
Whey protein
isolate
90–95% 0.5–1 0.5–1% Used in protein supplementation products,
protein beverages, protein bars, other nutritional
food products
Hydrolyzed whey
protein concentrate
>80% (hydrolysis used
to cleave peptide bonds)
<8 <10% (varies with protein
concentration
Used in sports nutrition products
Hydrolyzed whey
protein isolate
>90% 0.5–1 0.5–1% Highly digestible form containing easy-to-digest
peptides that reduce risk for allergic reaction in
susceptible individuals commonly used in infant
formulas and sports nutrition products
Gangurde, et al.: Whey protein
74 Scholars' Research Journal / Jul-Dec 2011 / Vol 1 / Issue 2
Table 6: Differences between soy and whey
proteins
Soy protein Whey protein
Soy protein comes from
soybeans, which are legumes (a
source of carbohydrates)
Whey protein is made out of
natural sources as a diary by-
product
Soy protein does not provide an
excellent source of glutathione
Whey protein provides an
excellent source of glutathione
Does not contain plenty of
amino acids
Contains plenty of amino acids
Is the best for those women
who are vegetarians and for
body building
Is not the best source for the
vegetarians
ght heart disease, and speed up metabolism of the
thyroid, helping the body become leaner. Whey
protein is taken from milk as a diluted by-product
of cheese. It has been shown to be antibacterial, and
to assist in maintaining correct body weight, regulate
blood pressure, improve the immune system, and
improve the digestive system’s efciency [Table 6].[28]
In a study by a scientist, a mixture of amino acids
was administered in two groups which showed
almost identical effects to those of whey protein. Soy
protein is naturally high in amino acids which have
effects similar to those of whey protein.[29] In another
study, whey and soy proteins were administered to
two groups. The groups were both given the same
exercise routines. At the end of the study, the groups
which took the whey protein and soy protein, both
showed improvements in lean body mass. The only
difference in the two groups was that the group
which ingested the soy protein showed avoidance of
two negative effects like plasma radical scavenging
capacities in whey and training alone groups, while
the myeloperoxidase values rise that the whey protein
group suffered.[30]
Side Effects
Many people cannot tolerate nor have allergic
reactions to milk or other dairy products that contain
lactose. These people have what is called lactose
intolerance. Such lactose intolerant people may
develop allergic reactions after having whey protein
which is made from milk. However, two forms of
this protein – WPIs and WPHs – are processed to
remove the fat and lactose, and therefore they might
not cause allergy to such people who cannot tolerate
milk products. Whey protein consumed in very high
quantities can affect kidney functions negatively.
Extremely high doses of whey protein exert
unbearable pressure on liver and may lead to liver
damage. Again, if whey protein is taken excessively,
it can lead to an imbalance of minerals in the bones,
causing loss of bone mineral density. This can lead
to osteoporosis. Another probable side effect of
consuming whey protein is that it can lead to an
increase in the pH of blood. Excess protein in the
blood makes it difcult for the kidney to metabolize
it.[5,6]
Applications
Muscle building
Protein supplements are being used every day by
both old and young people. Most of these people are
avid exercisers who work out and tear their muscles
apart on a daily basis. Protein is what helps the body
build its muscles back together, and therefore has a
major role in making the human body stronger.[31]
Whey protein contains the highest percentage of
protein source and BCAAs. BCAAs help stimulate
protein synthesis or muscle growth which is
important in muscle building and muscle retention.
Whey protein also protects the degradation of muscle
protein. Whey is necessary in building blocks to
produce the amino acids that the body uses to build
lean muscle tissue.
[32,33] Whey is also a fast acting
protein, which means that it is absorbed quickly into
the bloodstream. It is widely believed that drinking
a protein shake that contains whey shortly after a
training session can speed up muscle recovery by
making the essential and BCAAs readily available to
the muscles. Low BCAA levels contribute to fatigue
and they should be replaced in 1 hour or less following
exercise or participation in a competitive event. Whey
protein is highly favored by bodybuilders because it
provides the necessary building blocks to produce the
amino acids that the body uses to build lean muscle
tissue. It is best taken in powder form mixed in
juice or milk, spread throughout the day to maintain
positive nitrogen. Whey protein is a relatively safe
supplement, but no more than 30 g of protein should
be taken at one sitting as excessive single doses could
overload the liver. The safety of whey protein has
been well documented in many scientic studies, and
there is clear proof that taken consistently, coupled
with regular exercise, it will result in meaningful
muscle.[34]
Weight management
Whey protein can play an important role in weight
management. Specic factors in whey protein like
leucine are being investigated for their ability to
promote weight loss by increasing satiety, inuencing
glucose homeostasis, and maintaining lean body mass
and promoting fat loss.[35] Whey has been shown to be
effective in increasing satiety and modulating energy
intakes, which may result in a loss of body fat and
weight.[36] Several studies have shown whey protein
to be more effective than soy, egg, and meat proteins
in suppressing food intake. For these reasons,
Gangurde, et al.: Whey protein
Scholars' Research Journal / Jul-Dec 2011 / Vol 1 / Issue 2 75
incorporating whey protein into the diet could be an
ideal solution for the many consumers interested in
high-protein and moderate carbohydrate diets.[37,38] C.
In diseased condition
Chronic Fatigue Syndrome
Chronic fatigue syndrome (CFS) has been linked to
abnormalities found in both hormonal and cellular
immunity. Tests consistently indicate that those
diagnosed with CFS have an impaired lymphocyte
(T-cell) response. The ability of lymphocytes to react
to an immune challenge is directly related to their
Glutathione (GSH) status. GSH is arguably the most
important water-soluble antioxidant found in the
body. It is a tripeptide made up of the amino acids
l-cysteine, l-glutamine, and glycine. It is also essential
for aerobic muscular contractions, an undesirable
competition for GSH precursors between the immune
and muscular systems may develop. Whey protein
is the most effective way to deliver precursors for
GSH synthesis. Whey may be especially effective for
people suffering from CFS.[39,40]
Viruses and HIV
Whey has the ability to suppress the viral load and
improve immunity in people with HIV. HIV infection
is characterized by increased oxidative stress, and a
systemic deciency of GSH is known to be essential
for immunity, oxidative stress, and general well-being.
The amount of GSH present is directly related to
lymphocyte reactivity to a challenge, which suggests
that intracellular GSH levels are one way to modulate
immune function. A large amount of available
cysteine is used for the synthesis of GSH. Different
strategies to supplement cysteine are being used to
increase GSH levels in HIV-infected individuals. For
example, N-acetyl cysteine (NAC) and alpha lipoic
acid are well known for increasing the levels of
GSH. In GSH-decient patients with advanced HIV
infections, short-term oral supplementation with
whey protein increases plasma GSH level.[41-44]
Blood Pressure
Hypertension has also been linked to an enzyme
secreted by the kidneys called angiotensin converting
enzyme (ACE). ACE has been clinically associated
with the rennin angiotensin system, which regulates
peripheral blood pressure. By blocking the effects of
ACE, blood pressure can be brought under control.
Whey peptides, known as lactokinins, have recently
been shown to be mild ACE inhibitors.[5]
Gastrointestinal System
Whey plays an important role in the protection
of the gastrointestinal system. In one experiment,
gastric mucosal injury was induced by either alcohol
(ethanol) or water immersion restraint stress where
the rats are put in water at 28°C for 7 hours. a-LA,
one of the chemical constituents of whey, has marked
antiulcer activity, suggesting that a-LA intake may
serve to protect against gastric mucosal injury in part
through endogenous prostaglandin synthesis.[45]
Kidney Diseases
Whey has extremely high Protein Efciency Ratio
which is important in conditions like renal failure
where protein intake must be limited and it is most
prudent to consume the highest quality proteins (like
WPI and egg white proteins) rather than lower-quality
proteins (like red meat and dairy) that produce
more problematic metabolic waste by-products and
residues.[5]
In Males
For promoting weight loss, increasing the muscle
mass, healthy aging and athletes and body builders,
whey protein is the most easily and quickly absorbed
protein available. It helps build muscle by stimulating
maximum protein synthesis.[5,46]
In Females
The second most abundant component in whey
protein is a-LA, which is one of the main whey
proteins in human breast milk. They are not allergic
to dairy proteins. For tatting women protein is
essential for proper fetal and infant development,
particularly brain development, and helps prevent
gestational diabetes.[46]
In Children
Whey protein helps stabilize children’s blood sugar
and increases the production of feel-good brain
chemicals that help increase mental clarity and focus.
It also provides the protein essential for growing
bodies, particularly brain.[47]
In Adults and Elderly People
As a person get older, his/her body becomes less
efcient in absorbing protein. Whey protein is the
most easily absorbed protein available. It can reverse
the aging process and rebuild the immune system. It
can ensure that you are rarely, if ever, sick, and that
you will begin to look and feel years younger.[48]
CONCLUSION
Whey protein is a pure, natural, high-quality protein
from cow’s milk. It is a rich source of all of the
essential amino acids needed on a daily basis by the
body. In its purest form, as WPI, it contains little to no
fat, lactose, or cholesterol. Whey protein has one of the
highest PDCAAS (a measure of protein bioavailability)
and is more rapidly digested than other proteins such
as casein. Whey is available in three major forms,
i.e. WPCs, WPIs or WPHs. WPI has been further
Gangurde, et al.: Whey protein
76 Scholars' Research Journal / Jul-Dec 2011 / Vol 1 / Issue 2
differentiated into micro-ltered undenatured isolate,
undenatured WPI, and WPI bars. Whey proteins are
both easily digested and have excellent metabolic
efciency, giving the protein a high BV. They contain
the highest percentage of protein source and BCAAs.
BCAAs help stimulate protein synthesis or muscle
growth, which is important in muscle building and
muscle retention. Whey may also support a healthy
response to stress and help maintain healthy levels of
the brain’s neurotransmitters. There are some great
benets of the whey protein on HIV infected person.
It is benecial in conditions like hepatitis, blood
pressure, chronic fatigue, kidney diseases, for weight
loss, and for an increase in the immune power. Unlike
many proteins, whey offers a valuable combination of
proven scientic efcacy and pleasant consumption.
In short, whey protein has all that we want.
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Source of Support: Nil, Conict of Interest: None declared.
... Its volume as a surplus is considered high, because 9 L of whey is produced for every 1 kg of cheese [8]. However, it is made up of 6.5% of total solids, of which 0.8% is protein (20% of all milk protein), 0.5% fat and 4.5% lactose, in addition to minerals such as calcium [9,10]. The main proteins present are β-lactoglobulin, α-lactalbumin, casein, immunoglobulins, lipoprotein, bovine serum albumin (BSA), lactoferrin, lactoperoxidase, bioactive peptides and essential amino acids [9,11]. ...
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Whey protein concentrate (WPC) solutions containing 10, 30, 60 and 120 g dry powder/kg were heated at 75°C and whey protein aggregation was studied by following the changes in the distribution of -lactalbumin and bovine serum albumin, using one dimensional and two dimensional PAGE. The one dimensional PAGE results showed that a minimal quantity of large aggregates was formed when 10 g WPC/kg solutions were heated at 75°C for up to 16 min whereas appreciable quantities were formed when 30, 60 and 120 g WPC/kg solutions were similarly treated. The two dimensional PAGE analysis showed that some disulphide-linked -lactoglobulin, -lactoglobulin in each sample were greater than the quantities of native-like protein. However, in WPC solutions of 10, 30 and 60 g/kg, the differences between the amounts of native-like and SDS-monomeric proteins were slight. The loss of the native-like or SDS-monomeric proteins was consistent with a first or second order reaction. In each case, the apparent reaction rate constant appeared to be concentration-dependent, suggesting a change of aggregation mechanism in the more concentrated solutions. Overall, these results indicate that in addition to disulphide-linked aggregates, hydrophobic aggregates involving -lactalbumin and bovine serum albumin were formed in heated WPC solution at high protein concentration, as suggested by model studies using binary mixtures of these proteins.
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The changes in protein aggregation and storage modulus of mixtures of β-lactoglobulin and α-lactalbumin were measured, by gel electrophoresis and dynamic rheology, respectively, during 60 min of heating at 75 or 80 °C in a buffer simulating the whey protein concentrate environment. The results were consistent with the formation of heat-induced hydrophobically bonded aggregates involving both α-lactalbumin and β-lactoglobulin that undergo disulfide bond interchange reactions within the aggregate as the basis for the generation of gel strands and gels. The apparent difference in response to heat treatment at 75 °C between mixtures of bovine serum albumin (BSA) and β-lactoglobulin and mixtures of α-lactalbumin and β-lactoglobulin is likely to be based on at least three factors:  the different thermal transition temperatures of the three proteins; the possibility of self-initiation of thiol−disulfide interchange reactions for BSA and β-lactoglobulin, but not α-lactalbumin; and the ability of α-lactalbumin to form interprotein aggregates with each of the other two proteins prior to disulfide bond interchange and gelation. Keywords: Whey protein concentrate; hydrophobic aggregation; disulfide bonding