Applications of Whey as A Valuable
Ingredient in Food Industry
Chandrajith VGG* and Karunasena GADV
Department of food science and technology, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
Submission: July 06, 2018; Published: July 19, 2018
*Corresponding author: Chandrajith VGG, Department of food science and technology, University of Sri Jayewardanepura, No.3/3c, Kahapola, Madapatha, Sri Lanka, Tel: 07152366149; Email: [email protected]
How to cite this article: Chandrajith VGG, Karunasena GADV. Applications of Whey as A Valuable Ingredient in Food Industry. Dairy and Vet Sci J. 2018;
6(5): 555698. DOI: 10.19080/JDVS.2018.06.555698
Many scientific researches have been carried out on utilization of whey which is considered as a waste in dairy industry. It is hazardous to dispose whey directly in to the environment because several toxic substances are formed during decomposition of whey and it can cause several harmful consequences on the environment. Whey protein fraction consists of many useful nutrients that can be benefitial to human nutrition. This study presents the possible applications on whey in food industry and other fields and the possibility to recycle the whey incorporating them in to secondary dairy products.
When the nutrients in whey is concerned cheese, whey contains about 50% of milk solids, including almost 100% of the lactose and 20% of the total protein . The recovery of such high-nutritional-value components from whey in a profitable way remains a topical challenge. Although whey was first considered to be a waste product and eliminated by the cheapest method possible, it is now being used to produce of a wide range of food products and food ingredients, such as whey-protein-based ingredients . Whey proteins are of several types: Sweet whey, Acid whey, Salty whey. Sweet whey differs from acid whey in terms of pH as well as concentrations of proteins, lactose, ash and minerals . Total solid content, protein content lactose content, mineral content and several components determined in previous research  is shown in Table 1.
It has been determined that Bovine whey and individual whey protein exhibit antioxidant activity. This bioactivity is observed with different commercial whey products (Whey Protein Isolate, Whey Protein Concentrate), is relatively resistant to processing method, and is increased by enzymatic hydrolysis . The absence of phenylalanine in glycol (caseino)macropeptide in whey protein makes it attractive for use in food formulations for phenylketonuriacs .
Whey can also be incorporated in to different food products
to increase the nutrient level of the food products and several
positive impacts could be brought about in food products by incorporating whey. Several previous researches have been carried out by altering different characteristics of whey. Possibility of incorporating whey in to cheese has been studied. The effect of the diameter of whey protein aggregate on the gel firmness has been studied. Regardless of whey origin, adding larger-diameter whey protein aggregates to cheese milk had no negative impact on rennet-induced coagulation, whereas smaller aggregates decreased curd firmness. Adding whey protein aggregates to milk increased cheese yield and moisture, and the dispersion method had no influence on these parameters, suggesting that a valve homogenizer is not required, which simplifies the process for artisanal cheese production  and it also has been found that the acid gels from milk with added whey protein had higher gel stiffness and yield stresses than those without added whey protein . Studies also showed that the addition of 1% whey protein concentrate to milk before heating almost doubled the stiffness of acid gels prepared from the milk the protein content was increased, and the fat content was decreased by adding whey protein aggregates to milk, suggesting good retention of added protein, or reduced retention of fat in cheese .
The effect in enriching food systems with Microparticulate whey protein and Nanoparticulated whey protein has been studied and the results showed that the formation of disulphide-linked structures in milk model systems was closely related to the increased particle size and rheological behavior of the gels.
Microparticulated whey protein enriched systems produced,
upon acidification, weak protein networks and required the
addition of whey protein isolate (WPI) to increase gel strength.
However, systems containing Nanoparticulate whey protein
exhibited pronounced increase in particle size and higher
firmness of acidified gels through both covalent and non-covalent
Values are means ± standard deviation (SD) means of at least 4 independent measurements (n ≥ 4); different lowercase superscripts in the
same row depict the significant difference between means for each whey concentrate.
Nanoparticulate whey protein are used as ingredients for
fat replacement in several food products, such as ice cream,
fermented milk, cheese, sauces and dressings. Such particles
can be manufactured in diameters ranging from 1 to 10 mm.
Nanoparticulate whey protein can also act as emulsifiers and
fat substitutes but exhibit smaller particle sizes . The use
of whey proteins as texture enhancers in yoghurt has become
a common practice due to their nutritional and functional
properties [12,13]. Developing of aerogels is another possible
application of whey. Blending whey protein with alginate allowed
for the production of bio-based aerogels with better mechanical
properties than those produced with whey alone, though thermal
properties was slightly decreased by blending .
Whey proteins can also be used for encapsulation. Whey
protein concentrate could delay the photodecomposition of
folic acid and the protective effect increased gradually during
irradiation and the increase in the absorbance at 365nm and
antioxidant activity of Whey protein concentrate contributed
to the protein improved protection against the decomposition
of folic acid. Whey protein concentrate could thus be a good
carrier material for the protection of folic acid . According
to the in vitro digestibility tests, the whey proteins isolate had
the ability to protect the anthocyanins in the stomach, while the
microencapsulated powder displayed a stimulatory effect on the
growth and viability of L. casei 431® .
A study showed that formation of nanocomplexes between
pectin and whey protein concentrate as wall materials was
capable of encapsulating appreciable amounts of d-limonene.
The optimum whey protein concentrates pectin nanocomplex
containing d-limonene can be used in products such as cakes,
muffins, biscuits, juices etc. since this vital flavoring can be
protected in products during processing and storage and its
release can be controlled .
Whey protein fortified foods and beverages are becoming
increasingly popular, particularly among consumers that are
active in sports for physique building purposes. Heat treatment
of whey protein isolate solutions (5 to 10%) at low pH resulted in
formation of protein fibrils, which led to a pronounced increase
in the viscosity of the protein solutions (from 1.6 to 2300mPa)
due to the increased effective volume and the rate of energy
dissipation. High-pressure processing (microfluidization) could
be used to decrease the mean length of the fibrils (from around
310 to 97nm) and therefore alter their thickening characteristics.
The turbidity of all the whey protein solutions increased
to greater than 1 cm-1 near the isoelectric point, which was
attributed to extensive protein aggregation due to weakening of
the electrostatic repulsion between the molecules .
Ultrasound treatment has been applied in previous research.
The effect of ultrasound power and exposure time of pretreatment
on lactose recovery has also been investigated. Ultrafiltration
has been subsequently used for the separation of proteins and
lactose from whey followed by anti-solvent son crystallization of
lactose using ethanol. Combined pretreatment using ultrasound
and heating resulted in maximum recovery  Ultrasound
treatment on post thermal aggregation has improving effect on physiochemical and emulsifying properties of whey protein
soluble aggregates for potential industrial applications. There
was a significant reduction in turbidity of whey protein solutions
by ultrasound. The apparent viscosity of whey protein soluble
aggregate model systems has been decreased significantly
influenced by ultrasound pre- and post- thermal aggregation.
Emulsion activity index and emulsion stability index of soluble
aggregates were increased significantly by ultrasound applied
post-thermal aggregation .
Application of membrane technologies such as Microfiltration
has been studied previous for whey protein. The Micro filtration
and Hydrogen Peroxide and Lacto Peroxidase bleached 80%
Whey protein concentrate displayed a 39.5, 40.9, and 92.8%
norbixin decrease, respectively. The Hydrogen Peroxide and
Lacto Peroxidase 80% Whey protein concentrate had higher
cardboard flavors and distinct cabbage flavor compared with the
unbleached and Micro filtration 80% Whey protein concentrate.
Volatile compound results were consistent with sensory results.
The Hydrogen Peroxide and Lacto Peroxidase 80% Whey protein
concentrate were higher in lipid oxidation compounds (especially
heptanal, hexanal, pentanal, 1-hexen-3-one, 2-pentylfuran, and
octanal) compared with unbleached and Micro filtration 80%
Whey protein concentrate. Micro filtration is a viable alternative
to chemical or enzymatic bleaching of fluid whey .
The FTIR analysis method uses infrared light to scan test
samples and observe chemical properties. Each molecule or
chemical structure will produce a unique spectral fingerprint,
making FTIR analysis a great tool for chemical identification.
FTIR spectroscopy is an established technique for quality control
when evaluating industrially manufactured material and can
often serve as the first step in the material analysis process. If
problems with the product are identified by visual inspection,
the origin is typically determined by FTIR microanalysis. This
technique is useful for analyzing the chemical composition of
smaller particles, typically 10 -50 microns, as well as larger areas
on the surface.
Confocal Laser Scanning Microscopy (CLSM) is convenient
and effective instrument for relatively quick 2-and 3D imaging
of fracture surfaces. At least on the scale of the region as small as
128×128μm the 2D images clearly representing all elements of
the brittle cleavage fracture surfaces can be obtained by CLSM.
The resolution and quality of such images is high enough to rival
with those captured by SEM at the same magnification . A
primary use of circular dichroism is in analyzing the secondary
structure or conformation of macromolecules, particularly
proteins as secondary structure is sensitive to its environment,
temperature or pH, circular dichroism can be used to observe
how secondary structure changes with environmental conditions
or on interaction with other molecules. Structural, kinetic and
thermodynamic information about macromolecules can be
derived from circular dichroism spectroscopy.ia.