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Journal of Hygienic Engineering and Design
71
Review paper
UDC 664:612.39
APPROACHES FOR DELIVERY OF HEAT SENSITIVE NUTRIENTS THROUGH
FOOD SYSTEMS FOR SELECTION OF APPROPRIATE PROCESSING TECH-
NIQUES: A REVIEW
Mahesh Satpute1*, Uday Annapure1
1Food Engineering and Technology Department, Institute of Chemical Technology, Nathalal
Parikh Marg, Matunga (E), Mumbai - 400019, India
*e-mail: satputems@gmail.com
Abstract
Food contains many heat sensitive nutrients which
include vitamins, minerals, and nutrients having
functional properties such as pigments, antioxidant,
Bioactive compounds. Many processes during man-
ufacturing of food cause detrimental eects on these
nutrients. Retention of these nutrients in food prod-
ucts requires innovative approaches for process design
because of their sensitivity to a variety of physical and
chemical factors, which causes either loss of biological
functionality, chemical degradation and premature or
incomplete release.
This article reviews eect of Dierent Processes on Heat
Sensitive Nutrients and approach for selecting appro-
priate processing technology. Proposed target appli-
cation of nutrient is rst analyzed using scientic prin-
ciples, including materials science, physical chemistry
and biophysics. The scientic understanding is used to
develop a range of potential solution strategies from
which the most feasible is selected for further develop-
ment. Based on technological considerations, such as
cost, ease of manufacturing, adaptability, one of these
various possible solutions is nally implemented in the
actual food product.
The major advantage of Retro-design approach is that
it does not focus from the outset on a specic technol-
ogy. Application of Sensitive Nutrient is placed at the
centre and from there systematically works back to nd
a feasible technology to introduce or retain sensitive
nutrient in the food product.
A wide selection of delivery systems is available for the
use in food systems. Ultimately, one would like to relate
the characteristics of the delivery systems to the func-
tional attributes of the nal product, such as sensory,
physico-chemical and biological nutritional impact.
Studies have shown that use of Novel Thermal as well
as Non-thermal processing techniques such as Pulsed
X-ray Processing, Oscillating Magnetic Fields, Low-
Temperature Plasma, Ozone processing, Dense-Phase
Carbon Dioxide Processing of Fluid Foods, Ultra-sound
Processing of Food, High Voltage Arc for better reten-
tion of Sensitive nutrients.
Key words: Nutrient delivery system, Food system, Heat
sensitive nutrients, Retro-design approach, Processing
impact, Non-thermal processing techniques.
1. Introduction
1.1 Eect of processing on nutrients
1.1.1 Nutrients directly aected by heat treatments
Food contains many heat sensitive nutrients which
include vitamins, minerals, and nutrients having func-
tional properties. Vitamins are organic components in
food that are needed in very small amounts for growth
and for maintaining good health. The vitamins include
vitamin D, E, A and K (fat-soluble vitamins), and folate,
vitamin B12, biotin, vitamin B6, niacin, thiamin, riboa-
vin, pantothenic acid, and vitamin C (water-soluble vi-
tamins). Vitamins are required in the diet in only tiny
amounts, in contrast to the energy components of the
diet. Many processes during manufacturing of food
cause detrimental eects on these nutrients. Maximum
destruction during heat processes is of vitamin and
minerals. Vitamins are unstable in foods. Processing
and cooking conditions cause vitamin loss. The losses
vary widely according to processing method and type
of food. Vitamin degradation depends on specic pa-
rameters during the culinary process, e.g., temperature,
oxygen, light, moisture, pH, and obviously length of ex-
posure. Vitamin A is stable under an inert atmosphere;
however, it rapidly loses its activity when heated in the
presence of oxygen, especially at higher temperatures.
Carotenoids are extremely susceptible to degradation.
Their highly unsaturated structure makes them sensi-
tive to heat, oxygen, and light [1 and [2]. Vitamin D is
Journal of Hygienic Engineering and Design
72
susceptible to the alkaline pH range, light, and heat
[3 and 4]. However, fat content is probably the crucial
factor aecting retention during culinary treatment.
A high-fat content usually results in a high vitamin D
loss due to dripping o, while low-fat content might
probably disrupt thermal isolation and vitamin D is
more easy accessible to other aggressors (e.g., light).
Retention of vitamin D varied in the range of 60–90%
during culinary treatment of meat and sh [5].
In case of vitamin E most common heat treatments, such
as broiling or roasting, cause a high loss of the nutrient.
The vitamin E content in food treated in vegetable oil
increases or remains stable because vegetable oils are
a good source of the fat-soluble vitamin. Vitamin E is
unstable in the presence of reducing agents: oxygen,
light, and peroxides (occurring as a result of unsaturat-
ed fat auto-oxidation). Retention of vitamin E is in the
range of 44–95% during culinary treatment of various
types of meat, and 60 - 93% in the case of legumes.
Vitamin K shows stability during culinary treatment
combined with sucient human intake of this nutrient
world-wide. Cooking losses of L-ascorbic acid depend
on the degree of heating, leaching into the cooking
medium, surface area exposed to water and oxygen,
pH, presence of transition metals, and any other factors
that facilitate oxidation [6]. Higher retention values
were often observed in vegetables prepared by steam-
ing (up to 99%), microwave steaming and stir-frying
with oil, followed by stir-frying with water, and nally
by boiling which caused the most extensive damage,
with losses of up to 75%. Losses of AA are minimal
when vegetables are cooked without any water, while
maximum losses are associated with cooking in a large
amount of water and oxygen present [5].
Thiamine is highly unstable at alkaline pH. Stability de-
pends on the extent of heating and on the food matrix
properties. Thermal degradation occurs even under
slightly acid conditions. Thiamine is highly unstable at
alkaline pH. Stability depends on the extent of heat-
ing and on the food matrix properties. Thermal deg-
radation occurs even under slightly acid conditions.
Thiamine is more sensitive to heat than is riboavin [6].
Riboavin is stable with respect to both oxidation and
heat, but sensitive to light [7]. Riboavin is very resis-
tant to dry heat, acid solutions, and air (oxygen), but
very sensitive to light, especially at high temperatures
and pH values. During cooking riboavin leaches into
water. Among the heat treatments and vegetables
mentioned, the highest losses (up to 66%) were ob-
served in cabbage. Folate losses during cooking and
preparation are the result of a combination of thermal
degradation and leaching of the vitamin into the cook-
ing water [6].
Folate is sensitive to sunlight, air, and light and being
heated in acid solutions. Folate is lost in food during
cooking because it breaks down under heat and leach-
es into the cooking water. The presence of reducing
agents (AA) in the food can increase folate retention
during thermal processing. Folates of animal origin ap-
peared to be stable during boiling and frying.
Pantothenic acid is the most stable vitamin during
thermal processing with pH levels of 5 - 7. Large losses
can occur through leaching into cooking water during
preparation of vegetables. Niacin is the most stable
water-soluble vitamin. Processing and cooking proce-
dures do not deactivate niacin. Leaching is usually the
primary pathway of its loss during food preparation [6].
Retention of niacin is in the range of 45 - 90% within
the various culinary treatments of meat and legumes.
Thermal degradation of vitamin B6 increases as pH
rises. Vitamin B6 is resistant to heat, acid, and alkaline,
but sensitive to light in neutral and alkaline solutions.
Pyridoxal and pyridoxamine are more heat, oxygen,
and light labile than pyridoxine (the primary vitamer in
plants).
Vitamin B12 is generally considered to be stable under
most food processing operations, but like all water-sol-
uble vitamins, it is subject to large losses through
leaching into the cooking water. Vitamin B12 is normally
stable during pasteurization of milk, but up to 20% can
be lost during sterilization [8].
Biotin is stable when heated in the presence of light
and in neutral or even in strong acid solutions, but it is
labile in alkaline solutions. In general, biotin retention
is relatively high during heat treatment (80% in meat,
85–90% in milk pasteurization, 85–95% in legumes,
70% in preservation of fruits and vegetables) [5].
1.1.2 Nutrients became unavailable during heat
processing
Minerals are the inorganic elements, as calcium, iron,
magnesium, potassium, or sodium, that are essential to
the functioning of the human body and are obtained
from foods. Minerals also get aected by heat treat-
ment during processing. The study of processing im-
pact on the fate of minerals is modelled after the analy-
sis of vitamin or macronutrient loss during processing.
Since ash values (determined before and after process-
ing) do not drastically change, minerals seemed not
to be aected during food processing. The late Robert
Harris has summarised the maximum losses of minerals
during cooking to be not larger, on average, than 3%.
However, the classical nutritional evaluation of food
processing by global estimation of mass losses might
be misleading in the assessment of processing impact
on bioavailability [9].
It might be possible that minerals were not lost during
processing, but combined with co-nutrients or non-
food components. They may become unavailable for
Journal of Hygienic Engineering and Design
73
digestion due to these interactions. Moreover, the op-
posite eect may also occur: increased bioavailability
because of destruction of binding ligands (e.g. phy-
tates). Various review articles have focused on the mass
losses in unit operations, mostly concerned with the
losses of Ca, Zn and Fe [9].
Hazell and Johnson [10], proposed that the reaction
products of depolymerisation processes under the
high temperature and shear might change the chemi-
cal form of iron and make it more soluble which increas-
es its availability. There were no established changes in
the bioavailability of zinc and iron [11].
Since the inorganic and organic forms of metal ion
complexes can have dierent absorbability, knowl-
edge of the chemical form is pre-eminent for the un-
derstanding of the physiological impact of the mineral.
For example, it was shown that peptides liberated by
the digestion of meat enhance the bioavailability of
the soluble iron in the intestinal lumen [12]. Results of
interaction of minerals with unit processes are sum-
marised below [13].
Table1. Eect of heat treatments on minerals
Processing Possible causes of losses or gains
Boiling/Cooking Leaching oxidative losses phytate
retention
Blanching HCl extractability of Zn and Ca
increased
Pasteurisation,
steaming Few losses
Canning Complex destruction
Baking Phytate hydrolysis increase absorption
Frying Iodine losses
Drying Denaturation of binding proteins,
Maillard reaction
Fermentation Phytate content reduction, hydrolysis
Extrusion Phytase deactivation eects
controversial
Home
preparation
Too much water, no use of cooking
water (pasta 20%, veg. 15%) reduces
mineral bioavailibity
1.1.3 Nutrients having functional properties
This comprises wide range of bioactive compounds
such as pigments, antioxidant, and immune boosting
naturally occurring bioactive compounds. Volden [14]
reported that blanching, boiling and steaming resulted
in losses of 59%, 41% and 29% respectively in anthocy-
anin content of red cabbage. Curcumin loss from heat
processing of turmeric was 27–53%, with maximum
loss in pressure cooking for 10 min. Curcumin loss from
turmeric was similar even in the presence of red gram.
In the presence of tamarind, the loss of Curcumin from
turmeric was 12–30%. Capsaicin losses from red pep-
per ranged from 18% to 36%, with maximum loss ob-
served in pressure cooking. Presence of either red gram
or tamarind or both did not inuence the loss of cap-
saicin. Piperine losses from black pepper ranged from
16% to 34%, with maximum loss observed in pressure
cooking [15].
2. Nutrient Delivery Systems - Basics
The creation of novel functionality of heat sensitive
nutrients in complex food materials is of increasing im-
portance for the food scientists. Application of active
ingredients in food products often requires innovative
approaches because of their sensitivity to a variety of
physical and chemical factors, which causes either the
loss of biological functionality, chemical degradation
or a premature or incomplete release. The situation is
challenging not only because of the high sensitivity
to temperature, but also because of the complexity of
many food products and the conditions prevalent in
many food matrices. In addition, product safety, ap-
pearance, storage conditions, ease of preparation by
the consumer, freshness and sensory properties of the
food product are not to be compromised by the incor-
poration of the heat sensitive nutrients.
Job Ubbink and Jessica Kruger [16] proposed target
application rst analyzed using scientic principles, in-
cluding materials science, physical chemistry and bio-
physics. The scientic understanding is used to develop
a range of potential solution strategies from which the
most promising may be selected for further develop-
ment. Based on technological considerations, such as
cost, ease of manufacturing, adaptability, one of these
various possible solutions may nally be implemented
in the actual food product. The major advantage of this
approach is that it does not focus from the outset on a
specic technology to solve an issue, which might be
poorly understood, and for which the selected technol-
ogy may ultimately be ineective.
In a retro-design approach to the delivery of heat sen-
sitive nutrients, the food application is placed at the
centre and from there one systematically works back
to nd a feasible technology to introduce the sensitive
nutrient in the food product. The principle of retro-de-
sign, as developed in organic synthesis, allows the sys-
tematic evaluation of all steps and routes starting from
the nal product down to the raw materials. In organic
chemistry, such a retro-design allows the evaluation of
all possible reaction pathways and intermediates lead-
ing to the desired product and facilitates the choice of
the favoured synthesis route based on a rational com-
promise between reaction yields, number of reaction
steps, and availability of starting materials. In addition,
the approach has proved useful as it allows the deni-
Journal of Hygienic Engineering and Design
74
tion of chemical transformations which do not yet exist
but whose development may then be attempted [17].
Figure 1. Flow diagram for retro-design approach
application for food application
In the food eld, application of this approach is very
useful, in particular in the development of complex
food products containing active ingredients. In adopt-
ing a retro-design approach towards the delivery of
sensitive nutrients in foods, one starts by dening pre-
cisely the functionality and performance of the active
ingredient desired in the nal application (Figure 1).
This target sets the required functionality and perfor-
mance of the active ingredient. This could be the pres-
ence of a dened quantity of vitamins or minerals (heat
sensitive nutrients) in a food product or the mainte-
nance of a bioactive form during the shelf life and the
digestion of a food product. Subsequently, the physi-
cal, chemical and biological properties of these nutri-
ents and the conditions prevailing in the food matrix
are analyzed (Figure 1). Such properties of these nutri-
ents include the physical properties, including phase
behaviour and molecular mobility, chemical reactivity
and conditions under which the physiological and sen-
sory characteristics are maintained and they eectively
determine the application window of the sensitive nu-
trients. If the target can be satised is then determined
by the conditions prevailing in the food matrix, during
manufacturing, storage and consumption. For deliv-
ery of heat sensitive nutrients through food product,
we have only a very limited exibility in adapting the
conditions in the food matrix to match the window
of application of these ingredients. Consequently, of-
ten conditions in the food matrix have to be accepted
which are detrimental to the stability and functionality
of the sensitive ingredient. In such situations, the sen-
sitive ingredient and the product may be said to be in-
compatible and a successful product development sat-
isfying the original requirements on the functionality
and performance of the active ingredient turns out to
be impossible. However, having clearly identied both
the conditions required for maintenance of the per-
formance of the sensitive ingredient and the limits to
the conditions set by the food matrix, one may dene
the functionality needed to resolve the causes of the
incompatibility of sensitive ingredient and food matrix.
The functionality is dened solely based on the analysis
of the interaction of sensitive ingredients, its stability
and food matrix and it does not yet relate to a specic
technology. In fact, a functionality dened in this way
may not even have an existing associated technology.
The major advantage of introducing the concept func-
tionality is that it postpones the selection of a technol-
ogy to a later stage in order to allow the optimal match-
ing of the dierent factors indicated in Figure-1. It
thereby enables a clear denition of the requirements
a novel technology should full in satisfying the spe-
cic application. Based on the dened functionalities,
one is in a position to select or develop an appropriate
technology.
2.1 Case Study: Delivery of Probiotic Cultures
through Food Systems
Job Ubbink [16] has studied application of Retro-
design approach for stability of probiotic cultures in
Food Matrix (Figure 2).
Figure 2. Retro-analysis of the delivery of probiotics in
food matrices
Probiotics are used as living microbial food additives
that benecially aect the host organism by improving
its intestinal microbial balance [18]. Most of the probi-
otic bacteria, in particular bidobacteria, are sensitive
microorganisms with low survival to stresses occurring
during the production, storage and consumption of
food products. Large fraction of the microorganisms
will lose their viability already before the moment of
consumption of the food product. These losses are
commonly larger than 1 log during the shelf life of the
product, but may be much higher. A number of tech-
nologies and strategies are being developed to sup-
port the survival of probiotics in food products during
Journal of Hygienic Engineering and Design
75
processing and storage, but the range of application of
such technologies and strategies is usually restricted to
a limited variation in conditions. One of the solutions
for probiotic stability is to use probiotic isolates and
extracts instead of Functionalities, viable microorgan-
isms. However, studies have shown that probiotic ex-
tracts and isolates cannot completely replace live pro-
biotics. Therefore, eective technologies are required
to stabilize microorganisms in the food matrix to be
able to develop probiotic food products. Strategies for
the stabilization of probiotic cultures in such dehydrat-
ed states develops based on general observations on
the response of the cultures to varying environmen-
tal conditions. Hence, application of Probiotic micro-
organisms is done in dehydrated food products, with
a water activity typically between 0.3 and 0.5 having
a shelf life of 1 - 2 years at room temperature. Under
these conditions, probiotic microorganisms lose their
viability in few months. In order to increase probiotic
stability in dehydrated products, the cultures store in
a very dry state (dehydrated regime). The probiotic vi-
ability rapidly increases with decreasing water activity.
This can be achieved by drying the product matrix to
the required water content. This is costly solution as
product weight loses from 1% up to 10% during de-
hydration. In addition, rendering a product extremely
dry may alter numerous product characteristics like
texture, palatability, and solubility. Another strategy to
protect probiotic microorganisms against the eects
of moisture is by encapsulation of the dry biomass in
materials, which form a barrier towards water. However
this has got limitations because hydrophobic food
materials like lipids have appreciable rates of mois-
ture migration. Protection against moisture strongly
enhances probiotic viability during storage; may be
due to moisture dependence reactions, including oxi-
dation, or to the eects of water on the conformations
of biological macromolecules. The impact of oxidation
reactions on probiotic stability may be limited by en-
capsulation of the microorganisms in a material with
high oxygen barrier properties, such amorphous glassy
carbohydrates which are having multiple associated
functionalities. [19]. Glassy carbohydrates are thought
to play an important role in the stabilization of fragile
biological structures such as lipid membranes, proteins
and nucleic acids by forming a physical stable matrix
interacting with the biological structure via hydrogen
bonding [20]. Microbiology is used as Stabilization
strategies complementary to previously discussed
physicochemical strategies. Strain selection and stress
adaptation, are become an important strategy to ad-
just probiotic viability [21]. Stress adaptation consists
in the application of sub-lethal or gradually increas-
ing doses of stress in order to stimulate an adaptive
cellular response that enables the microorganism to
resist a similar, but more intense stress at a later stage
[22]. Genetic tools, including bioinformatics of entire
genome sequences, were being used to increase the
understanding of molecular mechanisms of microbial
adaptation and protection [23].
Thus, structured analysis based on the ‘retro-design’
concept is useful as it oers a rational way to disentan-
gle the various physico-chemical and biological factors
determining probiotic stability. The nal processing
strategy will therefore not be optimal regarding a sin-
gle process step or ingredient but rather the best com-
promise in terms of the target product and the request-
ed product specications.
In this review, we have focused upon the types of deliv-
ery systems used for sensitive products, Novel thermal
and Non-thermal processing techniques with their im-
pact on sensitive nutrients. Finally heat sensitive nutri-
ents with their food application have been described.
Bio-fortication of nutrients is relatively recent concept
that needs to be studied extensively before implemen-
tation on Food Sector.
2.2 Types of Nutrient Delivery Systems
A wide selection of delivery systems is available for the
use in food systems. Ultimately, one would like to relate
the characteristics of the delivery systems to the func-
tional attributes of the nal product, such as sensory,
physico-chemical and biological nutritional impact
[17].
2.2.1 Powder particles
Spray-drying (micro) encapsulation has been used in
the food industry to provide, protection against deg-
radation/oxidation, and to convert liquids to powders.
Microencapsulation is dened as a process in which
tiny particles or droplets of the active ingredient(s) are
surrounded by a coating, or embedded in a homoge-
neous or heterogeneous matrix, to give small capsules
with many useful properties. Microencapsulation can
also provide a physical barrier between dierent active
ingredients in the solid product. microencapsulation is
done by spray drying, freeze drying, uid bed coating
and extrusion. Solid microcapsules represent the large
majorities of delivery systems used in food. Particle size
ranges from 1 to 2 μm. Such colloidal systems are much
less susceptible to creaming or sedimentation in the -
nal fortied liquid product. In order to avoid creaming
sedimentation in the latter systems, the aqueous con-
tinuous phase has to be viscous or gellied or density
matching components have to be added.
2.2.2 Oil in water emulsion
Oil in water emulsion such as milk, yogurt drinks, dress-
ings, sauces or mayonnaise, are ubiquitous in food.
Their oil droplets can easily be used for the delivery of
Journal of Hygienic Engineering and Design
76
lipophilic active ingredients. For example Vitamin E or
its derivatives are frequently added to the oil phase of
o/w emulsion products for fortication reasons or in
order to stabilize unsaturated oils against oxidation [24
and 25].
Since vitamin E acetate is chemically more stable than
vitamin E itself, it is especially used in food technology
for fortication reasons. For many nutrients, however,
a classical emulsion delivery system does not oer the
desired properties in terms of solubilization (e.g. pre-
venting crystallisation), protection against chemical
degradation or inducing the desired nutritional activ-
ity. For example, classical emulsion systems do not pro-
tect unsaturated triglycerides, essential oils, vitamins A
and D eciently against degradation.
Therefore other ideas are needed to deliver such in-
gredients without losing their nutritional eect during
shelf-life of the product. One way to achieve this is by
controlling the composition and structure of the oil
droplet interface, i.e., by building around the oil drop-
lets multilayer of surfactants.
- Multilayer emulsion system
McClements and co-workers [26] showed that when
stabilizing oil droplets rst with an anionic surfactant,
such as a phospholipid, and then adding a positively
charged polymer, such as chitosan to the emulsion, the
droplets are coated with a surfactant-polymermem-
brane, which gives the globules a positive charge. It
was observed that this kind of emulsion protects more
eciently Ω 3 fatty acids and essential oils (citral and
limonene) from oxidation that ordinary emulsions sta-
bilized by a single surfactant or amphiphilic layer. The
observed eect against oxidation of the oil droplets
in this multilayer emulsion system was attributed to
the net positively charged interface. A positive charge
around oil droplets hinders the contact with transition
metals, like iron or zinc, and as a consequence, pre-
vents them to act as a pro-oxidant of the oil droplets. It
is also suitable for water–oil droplet interface, reducing
oxidation of sensitive oil droplets, like poly-unsaturat-
ed fatty acids (PUFA), essential oils such as citral and
limonene [27].
-Double Emulsion
Double emulsions, also often denoted as ‘multiple
emulsions’, are “emulsions of an emulsion”, e.g. a water-
in-oil emulsion dispersed in an aqueous phase (water-
in-oil-in-water, W/O/W). Such emulsions are interesting
as delivery systems, since, in principle, the water drop-
lets inside the oil droplets can be used to deliver (un-
stable) hydrophilic active ingredients separating them
from the outer aqueous phase of the food product.
Therefore, most studied applications of double emul-
sions are related to the control of the release of hydro-
philic substances from the inner to the outer aqueous
phase [28]. Benichou [29] studied the double emulsion
stabilization potential of WPI (Whey Protein Isolate)/
polysaccharide(e.g. xanthan gum) complexes in com-
parison to each of the biopolymers alone. A synergis-
tic positive eect with regard to the double emulsion
stability was demonstrated, which was associated to
modied surface properties induced by the adsorption
of the complexes. The authors also showed that these
double emulsions can be used for entrapping hydro-
philic vitamins, such as vitamin B1, into the inner aque-
ous phase. By means of Dierential Pulse Polarography
it was possible to follow the real-time release of the en-
trapped vitamins from the core of the W/O/W double
emulsion droplets to the outer aqueous phase.
- Nanoemulsions
Nanoemulsions, often also called miniemulsions, are
emulsions consisting of droplets which are signicantly
(by a factor of 10 or so) smaller than the droplets pres-
ent in ordinary emulsions. The very small droplet size
of nanoemulsions (20 - 200 nm) makes them resistant
to physical destabilization via gravitational separation,
occulation and/or coalescence. Nanoemulsions are
resistance due to creaming because of Brownian move-
ments but they are particularly prone to growth in par-
ticle size over a time by a process known as Ostwald
ripening [30]. Yuang [31] investigated oil-in-water na-
noemulsions of β-carotene produced by high pressure
homogenization. While the physical stability of the
nanoemulsions, which were stabilized by polysorbate
emulsiers, was quite acceptable, signicant chemical
degradation of the delivered β-carotene occurred dur-
ing storage.
-Solid lipid nanoparticles carriers
Solid lipid nanoparticles carriers (SLNs) have some sim-
ilarities with nanoemulsion systems. The diameter of
such lipid particles can be also quite small, i.e. in the
range between 50 nm and 1 μm. SLNs consist of a solid
or semi-solid lipidic core containing lipophilic active in-
gredients. Active ingredients can be solubilised homo-
geneously either in the core of the SLNs or in the outside
part. This physical property allows a better control of
both the physical (against recrystallisation) and chem-
ical (against degradation) stability of the delivered nu-
trients. The preparation of SLNs is achieved by heating
the lipidic core components above their melting point,
and then using common emulsion or microemulsion
technology, i.e., homogenisation or mixing of the melt-
ed lipidic phase with a cold aqueous solution generat-
ing re-crystallised lipidic particles. The main diculty
associated with SLNs production is to control the lipid
Journal of Hygienic Engineering and Design
77
polymorphism. Triglycerides, for example, can be pres-
ent in three dierent crystalline structures α (spherical),
β′ (needle shaped), and β (needle shaped) [32]. Carlotti
[33] found that between 50 and 70% of retinol remains
undegraded when ‘encapsulated’ in SLNs made of Cetyl
palmitate (30% of vitamin A was degraded), Glyceryl
behenate (49% degradation) and palmitic acid (34%
degradation), while 8% retinol remains when delivered
in standard oil-in-water emulsions.
But during heat treatment active element may be ex-
posed to high temperature during the preparation of
the lipid carrier material leading to chemical degrada-
tion. Finally, saturated lipids are needed to obtain these
kinds of delivery system. Such lipids are not the pre-
ferred ones in terms of nutrition and health.
2.2.3 Molecular Complex
Another strategy to deliver active ingredients in aque-
ous foods is by physically complexing them with other
molecules, hoping that in this way a better solubilisa-
tion and/or an increase in the chemical stability of the
complex bioactive can be achieved. In this context a
molecular complex is referring to the physical associ-
ation between a host and a guest (active ingredient)
molecule.
- Cyclodextrins
Cyclodextrins are cyclic (or taurus shape) oligosaccha-
rides having a hydrophilic outer surface insuring good
dissolution of the complex in an aqueous environment.
Cyclodextrins (α-6, β-7, γ-8) contain a lipophilic cavity
(0.5-0.8 nm) enabling to host relatively small lipophilic
or amphiphilic constituents, such as fatty acids, vegeta-
ble and essential oils, nucleic acids, vitamins and hor-
mones [34 and 35].
- Molecular association with biopolymer
Active molecules form physical complexes with a va-
riety of other naturally occurring food components.
Such systems are the base for designing ‘natural’ de-
livery systems. Amylose present in starch, which adopt
a helical structure generating a cavity of about 0.5 nm
in diameter. Small molecules like aromas solubilize in
this cavity and can bbe used in Food Delivery systems.
Proteins and peptides are amphiphilic molecules.
They are also relatively soluble in water and can bind
lipophilic or amphiphilic active ingredients. Semo [36]
used casein micelles to solubilize vitamin D2. Sodium
caseinate, CaCl2 and K2HPO4 were used to encapsulate
the vitamin and reconstitute the casein micelle solu-
tion and study their protective properties. It was found
that the casein micelle can provide a partial protection
against UV-light induced degradation compared to the
serum media of the casein micelle dispersion, which
was used as a control.
2.2.4 Self-assembly delivery structures
Tanford [37] dene the dimensionless surfactant pack-
ing parameter for a semi quantitative description of
the relation between surfactant molecular shape and
self-assembly phase formation. Packing parameter
is ration of the molecular volume of the hydrophobic
moiety, the molecular length of the hydrocarbon chain
and is the eective (or hydrated) cross-sectional area
of the polar head-group. Depending on packing fac-
tor, dierent self-assembly structures are formed. If
Packing parameter is less than 1, structures like normal
micelles, hexagonal (Hi) or cubic phases are formed. If
Packing parameter is close to 1, a lamellar liquid crys-
talline (Lα) phase is formed, which when dispersed into
water gives rise to vesicles or liposomes formation. If
packing parameter is more than 1, reversed self-assem-
bly structures, such as reversed micelles, reversed hex-
agonal or reversed cubic structures are formed.
Self-assembly structures, such as micelles, microemul-
sions, and liquid crystalline phases, are formed by the
spontaneous association of surfactants in aqueous (or
oil) phases. These consist of polar lipids such as mono-
glyceraldehydes and phospholipids. These are ther-
modynamically stable and are formed spontaneously
and as compared to nanoemulsion , microemulsion
requires large amount of surfactant [38]. For exam-
ple-polysorbate used to prepared β-carotene, lyco-
pene, lutein or phytosterols.
- Liposomes
Liposomes, often also denoted as vesicles, are formed
when the surfactant molecules have a Packing param-
eter close to 1. Contrary to microemulsions their forma-
tion is often not completely spontaneous. When mixed
with water the surfactant spontaneously forms a lamel-
lar phase, which then needs to be dispersed to form
vesicles. Liposomes can contain (i) one bilayer forming
unilamellar vesicles (ULV), (ii) several concentric bilay-
ers forming multi lamellar vesicles or (iii) non concen-
tric bilayers forming multi vesicular vesicles (MVV). The
size of these structures can be rather small (in the range
of 20 nm) or rather large (exceeding 1 μm) [39].
2.2.5 Dispersed reversed surfactant systems
Reversed phases are made out of surfactants that have
a Packing parameter more than 1. They are formed by
lipophilic surfactants such as unsaturated monoglycer-
ides or phospholipids. Reverse microemulsion droplets
can solubilize non-esteried phytosterol molecules in
Journal of Hygienic Engineering and Design
78
much larger amounts than in ordinary oil droplets can
do. Another interesting application of reversed micro-
emulsion droplets deals with the controlled release of
aromas [39]. Table 2 summarizes the various types of
systems which can be used for the delivery of sensitive
ingredients in aqueous liquid products.
Table 2. Delivery systems for sensitive nutrients
Delivery systems Particle
Size Salient Feature Limitations
1. Powder particles
- Glass encapsulation
- Core-shell capsule
- Matrix capsule
10 µm –
1 mm
Good encapsulation
for solid products
Limited application
for delivery of
sensitive nutrient in
liquid foods
2. Oil in Water Emulsion
- Ordinary emulsion
- Multilayered emulsion
- Double emulsion
- Nano-emulsions
- Solid lipidnanoparticles
carriers (SLNS)
100 nm
– 10 µm
50 nm –
1 µm
- Hosts lipophilic
molecules
- Better chemical
protection of
sensitive oil
achieved when
multi-layered
emulsion or SLNS
used
-controlled released
with SLNS
- Physical stability
- Polymorphism
stability and
encapsulation for
SLNS dicult to
control
3. Molecular Complex
- Cyclod3rins
- Molecular associated
with biopolymers
(Amylose, Proteins,
Protein aggregates)
10nm-
600nm
- Solubilisation of
small lipophilic
molecules
- Protection of
sensitive molecules
Limited Loading
Capacity of
Sensitive Nutrient
with Molecular
Complexes
4. Self-assembly delivery systems
Oil in Water Micro-
emulsion
5nm -
100 nm
-Solubilisation of
lipophilic molecules
-Solubilisation
of crystallizing
molecules
-Increased in
bioavailability
-Transparent
appearance(water)
-Large amount of
surfactant needed
-often o taste
-Used surfactant
often not well
accepted
Liposomes, Vesicles 20 nm -
100 µm
- Solubilisation of
hydrophilic and
lipophilic molecules
- Sustained released
of nutrients
- Higher cost
(ingredients and
process)
- Poor loading
eciency and
capacity
5. Self - assembly Structures
- Cubosomes
- Hoxosomes
- Dispersed reversed
- Microencapsulations
- Micellosomes
100 nm
– 1 µm
-Solubilised
amphiphilic and
lipophilic mol.
-Controlled released
-Solubilisation
of crystallizing
molecules
Large amounts of
surfactant may be
needed
2.3 Use of Novel Thermal and Non-Thermal Techno-
logies for Heat Sensitive Materials
Traditional thermal treatments are a cornerstone of
the food industry providing required safety proles
and extensions of shelf-life. However, such treatments
may lead to losses of desired organoleptic properties
and damage to temperature labile nutrients and vita-
mins. Consequently, the food industry has long sought
alternative or synergistic approaches to provide the
treatment objectives. Novel thermal and non-thermal
technologies have been designed to meet the required
food product safety or shelf-life demands while mini-
mizing the eects on its nutritional and quality attrib-
utes. The potential of novel thermal electromagnetic
technologies such as Ohmic and microwave heating,
are promising alternatives to conventional methods of
heat processing. Such technologies are regarded as a
volumetric form of heating, in which thermal energy
is generated directly inside the food, does not rely on
limiting heat transfer coecients and the requirement
of high wall temperatures. Non-thermal processing is
often used to designate technologies that are eective
at ambient or sub-lethal temperatures. Some of these
technologies are enlisted below with their mechanism
of microbial inactivation and Food Applications. Very
limited number of studies has been done on eect of
these technologies on Heat Sensitive Nutrients in Food.
2.3.1 Microwave and Radio-Frequency processing
Microwave and radio frequency heating refers to the
use of electromagnetic waves of certain frequencies
to generate heat in a material [40 and 41]. Microwave
food processing uses dierent frequencies, allocated
by Federal Communications Commission (FCC), such
as for United States, 2450 (Domestic Use) and 915 MHz
(Industrial Purpose), similarly 5800 and 24125 MHz is
used for Heating Purpose. Radio frequency is used at
three dierent frequencies, 13.56 MHz, 27.12 MHz and
40.68 MHz. This is used in Food pasteurization, baking
and other processes in the food industry [42 and 43].
Heating principle of Microwave is similarly as that of
Radio Frequency involves two mechanisms - Dielectric
and Ionic. Water present in the food is the primary com-
ponent responsible for dielectric heating. Due to dipo-
lar nature, water molecules try to follow the electric
eld associated with electromagnetic radiation as it os-
cillates at the very high frequencies. Food Material to be
heated is placed between two metal plates which form
an electrical capacitor. The material becomes “lossy” di-
electric and absorbs energy from radio frequency gen-
erator which is connected across the two plates known
as electrodes. Such oscillations of the water molecules
produce heat. The second mechanism of heating with
microwaves and radio frequency is through the oscilla-
tory migration of ions in the food that generates heat
Journal of Hygienic Engineering and Design
79
under the inuence of the oscillating electric eld [44
and 45]. Salient features are Rapid and Uniform heat-
ing, Selective heating, Instant control, energy ecient.
Two mechanisms for inactivation of microorganisms by
microwaves have been suggested. The rst states that
microbial inactivation by heat through mechanisms
comparable to other biophysical processes induced by
heat, such as denaturation of enzymes, proteins, nucle-
ic acids, or other vital components, as well as disruption
of membranes [46]. A second mechanism for inactiva-
tion by microwaves involves non-thermal eects due
to selective heating, electroporation, cell membrane
rupture, and magnetic eld coupling [47].
2.3.2 Ohmic & Inductive heating
Ohmic heating (also referred as Joule heating, electrical
resistance heating, direct electrical resistance heating,
electroheating, and electroconductive heating) is de-
ned as a process wherein electric currents are passed
through foods with the primary purpose of heating
them. The heating occurs in the form of internal en-
ergy generation within the material. Salient feature of
Ohmic heating is presence of electrodes contacting
the food (unlike to microwave heating), frequency, and
waveform [48]. Ohmic heating is a thermal process in
which heat is internally generated by the passage of al-
ternating electrical current through a body such as food
system that serves as an electrical resistance. During
Ohmic heating, AC voltage is applied to the electrodes
at both ends of product body. The rate of heating is
directly proportional to electric eld strength, electri-
cal conductivity & the type of food being heated. The
electrical eld strength can be controlled by adjusting
the electrode gap or applied voltage, while the electri-
cal conductivities of foods vary greatly, but can be ad-
justed by the addition of electrolytes. Ohmic Heating
is having salient features: Rapid heating independent
of Heat transfer coecients, without hot surfaces for
heat transfer, heat sensitive food components are not
damaged by localized over-heating, suitable for vis-
cous liquids, energy ecient, suitable for continuous
processing [49].
The principal mechanisms of microbial inactivation are
thermal and mild electroporation occurs during Ohmic
heating. Electroporation is due to its low frequency (50
- 60 Hz), which allows cell walls to build up charges and
form pores. This is in contrast to high-frequency meth-
ods such as radio or microwave frequency heating,
where the electric eld is essentially reversed before
sucient charge buildup occurs at the cell walls. Ohmic
Heating is used for blanching, evaporation, dehydra-
tion, fermentation, extraction, sterilization, pasteuriza-
tion and heating of foods to serving temperature [49].
2.3.3 High Pressure processing
High-pressure processing (HPP) is a method of food
processing where food is subjected to elevated pres-
sures (up to 87,000 pounds per square inch or approx-
imately 600 MPa), with or without the addition of heat,
to achieve microbial inactivation or to alter the food
attributes in order to achieve consumer-desired quali-
ties. The technology is also referred as High Hydrostatic
Pressure Processing (HHP) and Ultra High Pressure
Processing (UHP). During pressure treatment, the ap-
plication of pressure is governed by Le Chatelier’s prin-
ciple. Due to iso-static pressure treatment, pressure
is transmitted in a uniform and quasi-instantaneous
manner throughout the whole sample, thus making
the process independent of volume and geometry of
the product. It has been generally accepted that the
iso-static principle is assumed to be true for high-pres-
sure food processing applications except heteroge-
nous large solid samples. Once the desired pressure
is reached, it is maintained for an extended period of
time without any further energy input. Due to micro-
scopic ordering at constant temperature, an increase in
pressure increases the degree of ordering of molecules
of a given substance. Fruits containing Air-spaces such
as Marshmallows or strawberries containing large air
packets are deformed during pressure treatment due
to dierences between the compressibility of air and
the rest of the food constutuents.
Fluid foods are processed in batch or semi-continuous
mode, consists of Pressure vessel, Top and bottom end
closures, Yoke (structure for restraining end closures),
High pressure pump and intensier for generating tar-
get pressures, Process control and instrumentation, A
handling system for loading and removing the prod-
uct. In the batch mode, liquid product is pre-packaged,
preconditioned and pressure treated. Semi-continuous
pressure equipment employs two or more pressure
vessels with free-oating pistons arranged to compress
the liquid foods [50].
In Pressure-assisted thermal processing (PATP), the
food is subjected to a combination of elevated pres-
sures and moderate heat for short duration. One of
the unique advantages of PATP is its ability to pro-
vide a rapid and uniform increase in the temperature
of treated food samples. High pressures at ambient
or chilled temperatures have been employed for pro-
cessing a number of liquid and semi-solid foods such
as fruit juices, purees, smoothies, jellies, guacamole,
etc. Several studies evaluated the benecial eects of
pressure treatment over conventional treatment on
preserving quality attributes of foods. Small molecules
such as vitamins, and avor compounds remain unaf-
fected by high pressure, while the structure of the large
molecules such as proteins, enzymes, polysaccharides,
and nucleic acid may be altered [50].
Journal of Hygienic Engineering and Design
80
2.3.4 Irradiation of food
Irradiation is a food-processing treatment endorsed
by a variety of professional and governmental organ-
izations. In reviewing the scientic literature on the
process, the US Food and Drug Administration (CFR,
2000) the US General Accounting Oce (GAO, 2000)
the American Dietetic Association (ADA, 2000) and
the UN World Health Organization (WHO, 1999) have
endorsed the technology as safe and eective. Recent
Studies shows that no detectable furan was produced
in most fresh and fresh-cut fruits and vegetables fol-
lowing a dose of 5 kilogray (10 kGy), a very high dose
in the context of food processing [51]. Irradiation Dose
ranges are characterized as low (less than 3 kGy), medi-
um (more than 3 and less than 10 kGy), or high (more
than 10 kGy). The irradiation treatment is based on the
energy absorbed by Food Material. There are currently
three methods of delivering doses of ionizing radiation
for food processing. Gamma radiations are produced
by radioactive isotope sources such as cobalt-60 (Co-
60) and Cacsium-137(Cs-137). These are highly pene-
trative rays. Gamma ray sources produce radioactivity
constantly and so need heavy containment and shield-
ing for safety. Dosing is controlled by exposure time.
Electron beams (e-beams) are streams of high energy
electrons (beta particles) produced by an electron gun
(can be turned on and o. Electron beams have limit-
ed penetration (3-4 cm) into food, and do not require
such high levels of containment and shielding to pro-
tect workers. X-rays are used to process foods is more
recent and coming as separate processing technology
[52].
Irradiation is a non-thermal process that can be applied
to juices, beverages, and other uid foods. Successful
use of this technology is contingent on developing irra-
diation protocols that achieve the desired antimicrobial
and food-safety goals while preserving (or improving)
the sensory and nutritional value of the product [53].
Reyes and Cisneros-Zevallos [54] showed Irradiation
eects on anthocyanin pigments depend upon the
nature of anthocyanin for example; diglycosides are
relatively stable towards irradiation dose compared to
monoglycosides. Eect of irradiation (1 - 3.1 kGy) on
mango shows minor eect of irradiation dose on the
total phenolic content while there was a signicant in-
crease in avonols after an 18 day storage period for
the irradiated fruits (at 3.1 kGy). Study conducted by
Lopez-Rubira [55] demonstrated insignicant changes
in anthocyanins and antioxidant activity of pomegran-
ate arils after exposure to UV-C (0.56 - 13.62 kJ/m2).
2.3.5 Pulsed X-ray processing
Electrons have a limited penetration depth of about 5
cm in food, while X-rays have signicantly higher pen-
etration depths (60 - 400 cm) depending upon the en-
ergy used. Pulsed X-rays are generated using radionu-
clide sources that utilizes a solid state-opening switch
to generate electron beam X-ray pulses of high inten-
sity.
The radionuclides Co-60 and Cs-137 are produced by
neutron bombardment of Co-59 and Cs-136 as a ssion
fragment of a nuclear power reactor operation. They
emit γ-radiation of discrete energy. These radionuclide
sources require permanent massive concrete shielding
to protect workers and the environment from their per-
manent radiation.
Second approach is electrically driven radiation sourc-
es that switch o when the radiation is no longer need-
ed are easier to incorporate into existing food pro-
cessing plant. Linear Induction Electron Acceleration
(LIEA) generates broad spectrum ionizing radiation by
targeting the accelerated electron beam to collide with
a heavy metal converter plate. This plate converts the
electron beam in X-rays with a broad-band photon-en-
ergy spectrum. Then, by ltering the energy spectrum
of the radiation, high-energy, highly penetrating radia-
tion is produced, resulting in smaller variations in dose
uniformity of food packages and higher quality. LIEA
can deliver dose rates many orders of magnitude high-
er than possible with Co-60 sources. Consequently,
ultra-short, high-intensity radiation treatments can be
applied, resulting in higher local radical concentrations
and favoring radical-radical recombination reactions.
This reduces the diusion of radical species, which are
thought to be responsible for undesirable eects of ir-
radiation on food quality. Salient Features of this tech-
nology are (1) exibility of controlling the direction of
the electrically produced radiation; (2) the exibility of
shaping the geometry of the radiation eld to accom-
modate dierent package sizes; and (3) its high repro-
ducibility and versatility. The kinetic energy limit for
X-ray irradiation is 5MeV [56].
X-ray treatment reduces or eliminates Salmonella se-
rovars in poultry, mold growth on strawberries and
sprout development in potatoes. Salmonella serovars
have been found to be the most radiation sensitive
of all pathogenic organisms on foods. As a method of
food preservation, X-ray treatment has low energy re-
quirements.
Microbial inactivation by all types of ionizing radiation
is thought to happen through 2 main mechanisms: di-
rect interaction of the radiation with cell components
and indirect action from radiolytic products, such as
the water radicals. The primary target of ionizing radia-
tion appears to be chromosomal DNA, although eects
on the cytoplasmic membrane may also play a role.
Changes to chromosomal DNA and/or cytoplasmic
membrane can cause microbial inactivation or growth
inhibition. Many studies have shown that ions, excit-
ed atoms and molecules generated during irradiation
have no toxic eect on humans [57].
Journal of Hygienic Engineering and Design
81
2.3.6 Ultra-Violet pasteurization
Ultraviolet processing involves the use of radiation from
the ultraviolet region of the electromagnetic spectrum
for purposes of disinfection. Typically, the wavelength
for UV processing ranges from 100 to 400 nm. This
range is further subdivided into UVA (315 to 400 nm) ;
UVB (280 to 315 nm) ; UVC (200 to 280 nm) UVC is called
the germicidal range since it eectively inactivates bac-
teria and viruses, and the vacuum UV range. (100 to 200
nm) that can be absorbed by almost all substances and
thus can be transmitted only in a vacuum. The germi-
cidal properties of ultraviolet irradiation are due to the
DNA absorption of the UV light, causing crosslinking be-
tween neighboring pyrimidine nucleoside bases (thy-
mine and cytosine) in the same DNA strand [58]. Due
to the mutated base, formation of the hydrogen bonds
to the purine bases on the opposite strand is impaired.
DNA transcription and replication is thereby blocked,
compromising cellular functions and eventually leading
to cell death. The amount of crosslinking is proportional
to the amount of UV exposure. The level of mutations
that can be reversed depends on the UV repair system
present in the target microorganism. Once the thresh-
old of crosslinking has been exceeded, the number of
crosslinks is beyond repair, and cell death occurs [59].
This mechanism of inactivation results in a sigmoidal
curve of microbial population reduction. To achieve mi-
crobial inactivation, the UV radiant exposure must be at
least 400 J/m2 in all parts of the product. Critical factors
include the transmissivity of the product, the geometric
conguration of the reactor, the power, wavelength and
physical arrangement of the UV source(s), the product
ow prole, and the radiation path length. UV may be
used in combination with other alternative process-
ing technologies, including various powerful oxidizing
agents such as ozone and hydrogen peroxide, among
others. Applications include disinfection of water sup-
plies and food contact surfaces. Recently, interest has
increased in using UV to reduce microbial counts in juic-
es [60].
UV light has broad antimicrobial action, providing eec-
tive inactivation of viruses, vegetative bacteria, bacterial
spores, yeasts, conidia and parasites. UV-light treatment
of liquid foods is performed by use of continuous UV
sources. Continuous UV treatments are performed by
mercury vapour-lamps that continuously emit UV pho-
tons and are called continuous-wave UV (CW UV) lamps
in both monochromatic and polychromatic modes [61].
UV-C illumination of grapes induces stilbene synthesis,
especially that of trans-resveratrol, which will yield a
phytochemical-enriched grape juice [60].
2.3.7 Pulsed Light processing
Pulsed light is a technique to decontaminate surfaces
by killing microorganisms using short time pulses of
an intense broad spectrum, rich in UV-C light (portion
of the electromagnetic spectrum corresponding to the
band between 200 and 280 nm). Material to be steri-
lized is exposed to xenon ash lamp that multiply the
power many fold. Power is magnied by storing elec-
tricity in a capacitor over relatively long times (fractions
of a second) and releasing it in a short time (millionths
or thousandths of a second). The emitted light ash has
a high peak power and consists of wavelengths from
200 to 1100 nm. The technique used to produce ashes
originates, besides high peak power, a greater relative
production of light with shorter bactericidal wave-
lengths [62].
The germicidal eect of UV light on bacteria is primarily
due to the formation of pyrimidine dimers, mainly thy-
mine dimers. The dimer inhibits the formation of new
DNA chains in the process of cell replication, thus re-
sulting in the inactivation (inability to replicate, called
clonogenic death) of aected microorganisms by UV
rays. On bacterial spores, UV-C treatment results mainly
in the formation of the ‘‘spore photoproduct’’ 5-thymi-
nyl-5,6-dihydrothymine, and in single-strand breaks,
double-strand breaks and cyclobutane pyrimidine di-
mers. As per photothermal eect, UV light with uence
(measured in Joule/meter2 and is the energy received
from the lamp by the sample per unit area during the
treatment) exceeding 0.5 J/cm2, the disinfection is
achieved through a rupture of bacteria during their
momentous overheating caused by absorption of all
UV light from a ash lamp [62]. Advantages of
Pulsed Lights Processing are rapid disinfection, lack of
residual compounds, absence of any extraneous chem-
ical, environment friendly. Areas need improvements
are Sample Heating by lamp, shadowing eect of mi-
croorganism, limited application in caser of irregular
and opaque surfaces [62]. UV-C illumination decreas-
es ascorbic acid content of juices at a similar level to
that caused by thermal treatments [63]. Also for orange
juice, a treatment of 299 mJ/cm2 destroyed about
50% riboavin and β-carotene, 17% vitamin C, 11% vi-
tamin A, and did not aect folic acid or vitamin E. In
apple juice, the reduction is reported to be from 5.4 to
4.0 mg/100 ml of juice. Besides the eect on micronu-
trients, the potential eect of UV light on antioxidant
capacity and related compounds is also important to
assess due to the benecial eects of phytochemicals
[64].
2.3.8 Oscillating Magnetic Fields for food preserva-
tion
Static Magnetic Field (SMF) and oscillating Magnetic
Fields (OMF) are used for their potential as microbial
inactivation techniques. For SMF, the magnetic eld in-
tensity is constant with time, while an OMF is applied in
the form of constant amplitude or decaying amplitude
sinusoidal waves. The magnetic elds may be homoge-
Journal of Hygienic Engineering and Design
82
neous (uniform magnetic eld intensity) or heteroge-
neous (magnetic eld intensity is inversely proportion-
al to distance from coil) [65]. OMF is used in the form of
pulses reverses the charge for each pulse, and the in-
tensity of each pulse decreases with time to about 10%
of the initial intensity [66]. Preservation of foods with
OMF involves sealing food in a plastic bag and subject-
ing it to 1 to 100 pulses in an OMF with a frequency
between 5 to 500 kHz at temperatures in the range of 0
to 50oC for a total exposure time ranging from 25 to 100
milli-seconds. Frequencies higher than 500 kHz are less
eective for microbial inactivation and tend to heat
the food material [67]. Magnetic eld treatments are
carried out at atmospheric pressure and at moderate
temperatures. The temperature of the food increases
2-5 0C [65].
Studies have proposed two theories to explain the in-
activation mechanisms for micro-organism and patho-
genic cells placed in SMF or OMF. The rst theory states
that OMF loose the bonds between ions and proteins.
Many proteins vital to the cell metabolism contain
ions such as enzymes, hormones, pre-cursors which
get damaged by OMF. A second theory considers the
eect of SMF and OMF on calcium ions bound in cal-
cium-binding proteins, such as calmodulin. Changing
magnetic eld to calmodulin causes cyclotron reso-
nance resulting in loosening of the bond between the
calcium ion and the calmodulin. This ultimately causes
metabolic disorder followed by cell death [66].
2.3.9 Use of Pulse Electric Field
PEF utilizes high intensity electric eld pulses to inacti-
vate microorganisms mainly in liquid foods at relatively
low or moderate temperatures (less than 600C), whilst
preserving the fresh avour, colour and integrity of
heat sensitive components. A typical PEF food process-
ing unit comprises of a high voltage pulse generator, a
treatment chamber, a uid handling system and con-
trol and monitoring devices. Depending on the par-
ticular PEF systems used, typical PEF treatment param-
eters include pulsed eld intensity of 15 - 50 kV.cm-1,
pulse width of 1 - 5 microseconds, and pulse frequency
of 200 - 400 Hz (pulses/s). Key parameters inuencing
microbial inactivation in PEF are pulse width, pulse
shape, adequate design of the treatment chamber and
polarity. Square-wave pulses are considered to be su-
perior to exponentially decaying pulses as the former
gives the treatment in a sustained and constant inten-
sity for the total duration of the pulse. Bipolar pulses
are reported to be generally more eective for microbi-
al inactivation than monopolar pulses.
The total phenolic content of a blend of orange, kiwi,
pineapple juice and soymilk was not aected by PEF
treatments conducted at 35 kV/cm, 4 microseconds
bipolar pulses at a frequency of 200 Hz for a total
treatment time of 800 microseconds and 1400 micro-
seconds. No eect of PEF was detected on phenolic
compounds. However, signicant reductions were ob-
served for vitamin C concentration which was reected
in a decrease in the antioxidant activity of the product.
Under the tested processing conditions the PEF treat-
ment caused a reduction in the vitamin C and antiox-
idant capacity which decline over time compared to
conventional thermal treatment [68 and 69].
The microbial inactivation principle is Electroporation
theory. PEF treatment at electric eld intensity greater
than a critical threshold of trans-membrane potential
of 1 V across the target cells causes irreversible pore
formation and destruction of the semi-permeable
barrier of the cell membrane. More recent studies also
show that hypothesis of microbial inactivation due to
membrane permeabilisation caused by PEF. It is gener-
ally reported that yeast cells are more sensitive to PEF
treatment than bacterial cells, and that Gram-negative
are more sensitive than Gram-positive bacterial cells
[70].
2.3.10 Low-Temperature Plasma for Food processing
A neutral gas is converted to plasma by the application
of energy in several forms including; thermal, electric
or magnetic elds and radio or microwave frequen-
cies, resulting in an increase in the kinetic energy of
the electrons of constituent gas atoms. This causes a
cascade of collisions in the gas resulting in the forma-
tion of plasma products of electrons, ions, radicals and
radiation of varying wavelengths including that in the
UV ranges. The eectiveness of plasma to inactivate
microorganisms on inert surfaces will depend greatly
on the equipment design and operating conditions
like gas type, ow rate and pressure. The methods of
generating discharges of low-temperature plasmas by
using electric elds of either DC, AC, pulsed DC, radi-
ofrequency, microwave, dielectric barrier, or electron
and laser beams. Electric elds are the most commonly
used method of generating plasmas for technological
applications.
Low-temperature plasmas are dierentiated into at-
mospheric or low pressure (in the order of 10 Pa. In the
atmospheric plasma, many collisions between the par-
ticles occur due to the density of the gas. This leads to
rapid exchanges of energy between the electrons and
heavier particles (ions, radicals and molecules) reach-
ing a steady state and resulting in temperatures of the
order of 10,000’s degrees Celsius. The chemical compo-
sition of low-temperature plasmas of nitrogen, oxygen
and carbon dioxide gas mixtures are dominated by
ions free radicals and highly reactive intermediate spe-
cies. Also if water vapour is present, highly reactive spe-
cies including H2O, H, OH are formed and also cluster
ions containing H2O. The generation of UV radiation oc-
Journal of Hygienic Engineering and Design
83
curs in the ranges 10 - 290 nm, and those wavelengths
above 200 nm, at a uence of several mWs.cm-2, are
responsible for microcidal eects. Plasma inactivates
both vegetative cells and bacterial endospores. Three
basic mechanisms have been attributed to the inac-
tivation of microbial spores in plasma environments.
These include destruction of DNA by UV irradiation,
volatilization of compounds from the spore surface
by UV photons and erosion or so called ‘etching’ of the
spore surface by adsorption of reactive species like free
radicals. Synergistic eects between these possible
mechanisms of inactivation can be expected, depend-
ing on the operational conditions and the design of the
plasma generator [70].
The eect is limited to the surface layers of food prod-
ucts, but since plasmas are able to ‘ow’ over the treat-
ed surface into ssures and depressions. The entire
surface can be treated, in contrast to other surface de-
contamination processes such as UV light. A number
of researchers have investigated the potential for cold
plasma treatment as a method of non-thermal decon-
tamination of ready to cook food, nuts, fresh fruits and
vegetables, cooked meats, raw chicken pieces and also
for packaging [71].
2.3.11 Chlorine Dioxide processing
Chlorine dioxide (ClO2) is one of the few compounds
that exists almost entirely as monomeric free radicals.
ClO2 cannot be compressed and stored under the pres-
sure because it is explosive, therefore the shipping of
ClO2 gas is impossible, and it has to be generated on-
site. Easy-to-use commercial systems exist on the mar-
ket for on-site ClO2 generation. They generally consist
of two sachets each one containing a precursor for ClO2
generation, which takes place upon mixing two com-
ponents.
Cell membrane has been identied as the primary tar-
get of ClO2 on microbial cells. Studies show chlorine di-
oxide directly aects microbial cells by inhibiting pro-
tein synthesis, loss of permeability control. The eect
of ClO2 was related to non-specic oxidative damage
of the outer membrane leading to the destruction of
the trans-membrane ionic gradient. Some studies also
show inhibition of division and associated metabolic
damage or damage to genetic material. Use of chlorine
dioxide for microbial deactivation on Lettuce, Cabbage,
Green bell, Baby Apple pepper, Apples, Mungbean
sprout, Blueberry, Melon, cucumber have shown sat-
isfactory results. The main advantage of ClO2 gas over
aqueous sanitizers is that gas has more penetrability; it
could therefore reach microorganisms protected from
aqueous disinfectants by surface irregularities or bio-
lms [72].
2.3.12 Ozone processing
Ozone (O3) results from the rearrangement of atoms
when oxygen molecules are subjected to high-voltage
electric discharge. The product is a bluish gas with a
pungent odor and strong oxidizing properties Ozone
inactivates microorganisms through oxidization, and
residual ozone spontaneously decomposes to non-tox-
ic products (i.e. oxygen), making it an environmentally
friendly antimicrobial agent for use in the food indus-
try. The strong biocidal characteristics of ozone are due
to a combination of its high oxidizing potential and
its ability to diuse through biological membranes.
Ozone is generated at Industrial scale on demand,
in situ through various methods. Electrical (Corona)
Discharge Method includes, adequately dried air or O2
(free from particulate matter and dried to a dew point
of at least - 60 0C) is passed between two high-voltage
electrodes separated by a dielectric material, which is
usually glass. The ozone/gas mixture discharged from
the ozonator normally contains 1 - 3% ozone when us-
ing dry air, and 3 - 6% ozone when using high purity ox-
ygen as the feed gas. In Electrochemical (Cold Plasma)
Method, an electrical current is applied between an an-
ode and a cathode in an electrolytic solution contain-
ing water and a solution of highly electronegative ani-
ons. A mixture of oxygen and ozone is produced at the
anode used for microbial reduction. In Radiochemical
Ozone Generation (RCOG), high-energy irradiation of
oxygen is happened to produce ozone. In Ultraviolet
Method, ozone is formed when oxygen is exposed to
UV light of 140 - 190 nm wavelengths. This splits the
oxygen molecules into oxygen atoms, which then com-
bine with other oxygen molecules to form ozone. Some
of Extrinsic Factors such as ow rate, ozone concentra-
tion, temperature and intrinsic factors such as pH and
Organic Matter aect the ozone ecacy. Ozone is very
unstable both in the gaseous phase and in solution, de-
composing into hydroxyl, hydroperoxy and superoxide
radicals. The reactivity of ozone is attributed to the oxi-
dizing power of these free radicals. Microorganisms are
inactivated by disruption of the cell envelope or disin-
tegration leading to cell lysis. The bacterial membrane
seems to be the rst site of the attack with proteins and
unsaturated lipids in the cell membrane being the pri-
mary targets. Additionally, ozone causes alteration in
membrane permeability leading to leakage of cell con-
tents and eventually causing lysis. Ozone shows favora-
ble microbial reduction (gram negative, gram positive
bacteria and spores) in milk, gelatin, albumin, casein,
meat products, apple juice, whey, water, orange juice
[73].
Kiwi fruit is a rich source of vitamin C and contains
more ascorbic acid than citrus fruits. Barboni [74] com-
pared the eect of ozone rich storage and air storage
over a period of 7 months on the vitamin C content of
kiwi fruit. Gaseous ozone concentration was 4 mg/h in
Journal of Hygienic Engineering and Design
84
the chamber at a temperature of 0 0C and a humidity of
90 - 95%. The authors did not observe any signicant
change in ascorbic acid content of kiwi fruit over a 7
month storage period at an ozone concentration of 4
mg/h in the chamber (2 m3) and a storage temperature
of 0 0C. Reports on the eect of ozone on other bioac-
tive compounds of exotic fruits are limited [74].
Ozone treatments were also reported to have minor ef-
fects on anthocyanin contents in strawberries [75] and
blackberries [76].
2.3.13 Dense-Phase Carbon Dioxide processing of
uid foods
Carbon dioxide is used because of its safety, low cost,
and high purity. Dense-phase carbon dioxide (DPCD)
treatment has attracted great interest in the non-ther-
mal treatment of liquid foods or liquid model solutions.
DPCD has been shown to inactivate microorganisms as
well as conventional heat pasteurization without the
loss of nutrients or quality changes that may occur due
to thermal eects. The temperature increase induced
by the pressure build-up is negligible. The treatment
times can range from about 3 to 9 min for continuous,
or from 120 to 140 min for semi-continuous or batch
DPCD processes.
A typical batch system has a CO2 gas cylinder, a pressure
regulator, a vessel, a water bath or heater, and a CO2
release valve. The sample is placed into the vessel and
the temperature is set to the desired value. Then CO2 is
introduced into the vessel until the sample is saturated
at the desired pressure and temperature. The sample is
left in the vessel for a period of time and then the CO2
outlet valve is opened to release the gas. Some systems
contain an agitator to decrease the time to saturate of
the sample with CO2. A continuous high-pressure CO2
system has been developed to process 1 L/h of liquid
at 40.0 MPa. The sample liquid was stored in two 5 liter
high-density polyethylene containers, both connected
to the pump. CO2 passed through an in-line 0.5 μm l-
ter and a cooling system, then pumped to four mixing
points. The pressurized CO2 was mixed with the liquid
and the mixture went to a temperature-controlled
holding tube. Several valves along the holding tube
allowed for sampling at dierent residence times. The
treated liquid depressurized through a capillary tube
inside a thermostatic bath. The liquid was degassed in
two containers.
The bacteriostatic action of pressurized CO2 compro-
mises dierent steps such as solubilization of pressur-
ized CO2 in the external liquid phase, cell membrane
modication, intracellular pH decrease, key enzyme
inactivation/cellular metabolism inhibition due to in-
ternal pH lowering, direct inhibitory eect of molecular
CO2 and HCO3 on metabolism, disordering of the intra-
cellular electrolyte balance, extraction of vital constitu-
ents from cells and cell membranes, physical disruption
of cell membrane. Most of these steps occur consecu-
tively and simultaneously in a complex and interrelat-
ed manner. Another mechanism shows that carbon
dioxide is having very high anity for plasma consists
in great part of lipid components. Due to the increased
membrane permeability caused by the reaction of CO2
with water, which lowers the extracellular pH, pressur-
ized CO2 may easily penetrate through the bacterial cell
membrane and accumulate in the cytoplasmic interi-
or of bacterial cells then structurally and functionally
disrupt the cell membrane due to a loss of the order
in the lipid chain If too much dissolved CO2 enters the
cytoplasm, the cells may be unable to expel all the re-
sulting protons and internal pH starts to decrease. If
the internal pH is lowered too much, cell viability will
be impaired leading to inhibition of cell metabolism
or denature certain proteins and enzymes essential for
metabolic and regulatory processes, such as glycoly-
sis, amino acid and peptide transport. Finally internal
damage of the metabolic processes induces microbial
inactivation. Studies on Microbial Inactivation in Liquid
Foods such as Whole skim milk, fruit juices like orange,
peach, carrot, mandarin, watermelon, pear, apple,
grapefruit a well as many harmful enzymes by Dense-
Phase shows 5 to 7 log reduction of Pathogenic bacte-
ria and yeast [77].
Chen J, investigated the eects of DPCD treatment of 8,
15, 22, 30 and 35 MPa for 5, 15, 30, 45, 60 min at 35°C,
45°C, 55°C, 65°C on vitamin C in Hami melon juice dur-
ing storage at 4 0C for 4 weeks. The authors found that
vitamin C concentration decreased following DPCD
processing, but percentage loss was lower than of the
untreated samples. DPCD also appear to prevent losses
of other potential bioactive compounds such as β-car-
otene. The study conducted by Chen J showed better
retention of β-carotene in DPCD (55 0C, 60 minutes, and
35 MPa) treated melon juice compared to convention-
al HTST pasteurization. Signicant losses (57.87%) in
β-carotene content was observed in heat pasteurized
samples. It should be noted that exact mechanism for
β- carotene stability is dicult to establish [78].
Many examples of the applications of the DPCD to juic-
es demonstrated the protective nature of the process
to antioxidants, phytochemicals, organoleptic attrib-
utes such as taste, color, and appearance. The relatively
low process temperatures, the lack of oxygen in the en-
vironment, and for some nutrients, the lower pH, pro-
tect the vitamins such as vitamin C. Since the process
can be made continuous, its control is easy [78].
However this technology is facing some challenges
such as lack of the commercially successful DPCD oper-
ation, higher cost of the operation, stringent environ-
mental regulations regarding the release of CO2 into
the atmosphere, both total capture and recycling of
Journal of Hygienic Engineering and Design
85
the gas needs to be designed into new systems, or a
carbon-neutral source of CO2 needs to be used, limited
data to satisfy the regulatory requirements [77].
2.3.14 Ultra-sound processing of food
Power ultrasound employed in food processing uses
the lower-frequency ranges of 20 - 100 kHz with a
sound intensity of between 10 and 1,000 W/cm2. The
vibrational energy is provided by ultrasonic transduc-
ers that convert electrical energy to sound energy of
which there are two types in common usage, piezoe-
lectric transducer and magnetostrictive transducers.
The driving force for the processing eects of sonica-
tion is acoustic cavitation. The cavitation bubbles are
generated by the ultrasound wave as it passes through
the liquid. Like any sound wave, it is transmitted as a se-
ries of compression and rarefaction cycles aecting the
molecules of the liquid. When the negative pressure of
the rarefaction cycle exceeds the attractive forces be-
tween the molecules of the liquid, a void is formed. This
void or cavity in the structure takes in a small amount of
vapor from the solution so that on compression it does
not totally collapse, but instead continues to grow in
size in successive cycles to form an acoustic cavitation
bubble. There are many thousands of such bubbles in
a liquid, some of which are relatively stable but others
expand further to an unstable size and undergo violent
collapse to generate temperatures of about 5,000 K
and pressures of the order of 50 MPa. The cavitation
bubbles formed in this way are divided into two types:
Stable cavition and Transient cavitation [79].
For the sterilization of liquid foods, higher acoustic en-
ergies are employed and the approaches can be classi-
ed as sonication alone, manosonication (pressure and
ultrasound), themosonication (heat and ultrasound),
or monothermosonication (heat, pressure, and ultra-
sound). The mechanisms through which ultrasound
aects microbial inactivation are induced by acoustic
cavitation which results in the weaking or disruption
of bacterial cells through various processes. Bacteria
cell wall damage, due to mechanical eects induced
by pressure gradients generated during the collapse of
cavitation bubbles within or near the bacteria. Second
process is shear forces induced by micro-streaming
which occurs in the bacterial cell itself. Third approach
suggest, chemical attack due to formation of free rad-
icals during cavitation which attack the cell wall struc-
ture leading to disintegration. In addition there will be
the formation of a small amount of hydrogen peroxide
via sonication, which itself is a bactericide. One of the
major bactericidal eects of ultrasound is attributed to
intracellular cavitation; that is, micromechanical shocks
that disrupt cellular structural and functional compo-
nents up to the point of cell lysis. Use of ultra-sound
processing for desired microbial reduction is studies
with various food products such as orange juice, apple
cider, mango juice, guava juice, tomato juice, whole
milk, skim milk. In terms of dairy products, especially
milk, ultrasound providing considerable benet at low-
er-temperature pasteurization [80].
Rawson investigated the eect of thermosonication
on the bioactive compounds of freshly squeezed wa-
termelon juice. They observed a higher retention of
ascorbic acid and lycopene at low amplitude level and
temperature. They also observed a slight increase in ly-
copene at low amplitude level [81].
2.3.15 High Voltage Arc discharge
High voltage arc discharge is a method to pasteur-
ize liquid foods by applying rapid discharge voltages
through an electrode gap below the surface of aque-
ous suspensions of microorganisms. When rapid high
voltages are discharged through liquids, a multitude
of physical eects (intense waves) and chemical com-
pounds (electrolysis) are generated, referred to as elec-
trohydraulic shock, which inactivate the microorgan-
isms [82]. Enzymes are also inactivated by high voltage
arc discharges.
Palaniappan and Sastry presented an extensive litera-
ture review on the eect of electrohydraulic shock on
the inactivation of microorganisms. They reported that
bacterial inactivation was not due to heating, but main-
ly to irreversible loss of membrane function as a sem-
ipermeable barrier between the bacterial cell and the
environment and to the formation of toxic compounds
(oxygen radicals and other oxidizing compounds). In
their review, it was concluded that chemical action is
a complex eect and depends not only on the voltage
applied but also on the type of microorganism, initial
concentration of cells, volume of the medium used,
distribution of chemical radicals, and electrode mate-
rial [83].
Inactivation is attributed to oxidation reactions medi-
ated by free radicals and atomic oxygen. There is no
signicant temperature increase during treatment by
arc discharge [84]. Gilliland and Speck found electro-
hydraulic treatment to be eective in inactivating at
least 95% of the vegetative cells of E. coli, Enterococcus
faecalis, Micrococcus radiodurans, Bacillus subtilis and
its spores. High voltage electrical impulses were dis-
charged at a rate of 1 V/s [85].
2.4 Sensitive Nutrients with their food systems
Thus delivery of heat sensitive nutrients through food
systems posed a challenge for food scientist to satis-
fy often conicting requirements with respect to the
incorporation of sensitive active ingredients in food
products of increasing complexity have provoked a
Journal of Hygienic Engineering and Design
86
growing interest in the development and application
of delivery systems for foodstus. In many cases, how-
ever, it is dicult to apply established encapsulation
technologies without modication to an application of
interest, principally because the physical and chemical
behaviour of the sensitive ingredients and the func-
tionality of the delivery system are poorly understood.
So systematic evaluation of various aspects of food sys-
tems should be done at the time of developing food
systems delivering heat sensitive nutrients. Some ex-
amples of such food systems are described below with
appropriate explanation.
According to FAO/WHO (2004), the recommended in-
take for vitamin A is 375 µg Retinol Equivalent (RE) per
Day (for Infants) upto 600 µg RE per Day (for Adults).
Iron requirements are 4.2 mg per Day (for children)
upto 9.1 mg per day for adult males and 7.5 – 19.6
mg per day for adult females at 15% bioavailability.
Calcium requirements are 500 - 700 mg per Day (for
children), 1000 mg per day for adult males and 1000
– 1300 mg per day for adult females. Vitamin C require-
ments are 30 - 35 mg/Day (for children), 45 mg/day
for adult males and females. The recommended daily
intake (RDI) for Iodine for adult is 100–150 µg/day for
Adults and 90 -120 µg/day for children [86].
2.4.1 Vitamin A, Iron and Iodine:
Rutkowski and Diosady [87], developed a triple for-
tied which contained Vitamin A (250 IU per gram of
salt), Iron (1000 ppm) and Iodine (50 ppm). Vitamin A
is used in the form of vitamin-A palmitate, iron in the
form of ferric NaEDTA and iodine in the form of potas-
sium iodate. Here stability of vitamin A is maintained
by using Shellac as a hydrophobic coating agent. They
also found good stability of vitamin A, Iron and iodine
during processing and storage. Vitamin A is also used
in the form of retinyl acetate at 257.85 µg per 100 g of
cookies and shows minimum losses during baking i.e.
8.69 - 11.11%. It fulls our 45 % RDA of vitamin A [88].
2.4.2 Calcium
Food products nd wide range of calcium fortied food
products in market. Meat sausage fortied with calci-
um lactate and calcium glutamate at concentration
of 27 - 32 mg per 100 g of product [89]. Apple slices
are also impregnated with calcium upto 140 - 250 mg
per 100 gm [90]. Often vitamin C in combination with
calcium fortied in food to enhance the bioavailability
of calcium. Calcium enriched food products contains
wheat our tortillas (48 g per 100 g) [91], mango yogurt
(50 mg per 100 g) [92], soy milk (24.96 - 28.8 mg per
100 g) [93] which provides 20 to 40 % RDA for calcium
(1000 mg per day).
2.4.3 Zinc
Zinc, in the form of zinc sulphate and zinc oxide is
used to fortied parboiled rice at concentration 13.2
- 44.1mg per 100 g [94]. Zinc oxide (30 ppm) in combi-
nation with NaFeEDTA (40 ppm) used in whole wheat
our [95].
2.4.4 Iodine
Potassium iodide is used to enriched salt in combina-
tion of iron (ferrous fumarate) at concentration up to 50
mg per kg. It is also used during manufactured of meat
burger and meat balls with wheat bre and soy isolate
impregnated with KI and KIO3 (43 µg per 100 g) which
provides 30 % RDA (150 µg per day) [96].
2.4.5 Vitamin D
RDA for Vitamin D is 5 µg per day for children, 10 - 15 µg
per day for adult (FAO WHO 2004). It is used to enrich
milk (upto 5000 IU per 100 g), yogurt (5000 IU per 100
g) and ice-cream (5000 IU per 100 g) in the emulsied
form of vitamin D in butter oil [97]. In many countries,
milk, milk products, margarine, vegetable oil fortied
with vitamin D, used as a major dietary source. This
vitamin along with vitamin A and calcium used to
enrich dairy products. This fat soluble vitamin should
not cross the limit of 50000 IU per day through food to
avoid toxic eect.
2.4.6 Vitamin E
The RDA for α - tocopherol is 4 - 15 mg per day for
adults and children. Vitamin E is used to fortify ground
beef pattice (300 ppm)[98]. α – tocopherol succinate
which is heat and storage stable form of vitamin E is
used in soft drinks and ice-crieams. Microdispersion of
vitamin E (alpha-tocopheryl acetate) in milks showed
increased molar ratio of plasma tocopherol to choles-
terol (2 times) compared with Vitamin E capsules [99].
2.4.7 ω-3 long chain PUFA
These are used to fortify yogurt, cream (1 - 5 mg per 100
g). Also in cheese (30 mg per 100 g), processed cheese
(40-60 mg per 100 gm), spreadable fresh cheese (20 mg
per 100 g) [100].
2.4.8 Vitamin C
Ascorbic acid is most heat liable vitamin and also wa-
ter soluble so it is enriched in the combination of iron
in various food systems such as dairy products such as
cheese, yogurt, chocolate milk which increases the bi-
oavailability of iron in presence of vitamin C. It is also
Journal of Hygienic Engineering and Design
87
Table 3. Sensitive nutrients with their food systems
Sr. No. Chemical form Added concentration Food product References
Calcium
1. - Calcium citrate
- Calcium lactate
- Calcium gluconate 27 - 32 mg/100 g of product Meat Sausage [89]
2. - Calcium lactate 140 - 250 mg/100 g of product Vacuum impregnated apple slices [90]
3. - Calcium carbonate
- Calcium citrate
- Calcium lactate 48 mg/100 g of product Wheat our tortillas [91]
4. - Calcium lactate 50 mg/100 g of product Calcium fortied cow milk [105]
5. - Calcium lactate pentahydrate 50 mg/100 g of product Mango yogurt [92]
6. - Calcium glutamate 24.96 - 28.28 Soymilk [93]
Iodine
7. - Dextrin encapsulated
- Potassium iodide
- Ferrous fumarate
KI - 50 mg /100 g
Iodine - 100mg/100g of product Salt [106]
8. - Wheat bre and soy isolate im-
pregnated KI and Potassium iodate
43 µg/100 g
(30 % RDA) Meat burgers and meat balls [96]
Zinc
9. - Zinc sulphate
- Zinc oxide 13.2 - 44.1 mg/ kg Parboiled rice (polished) [94]
10. - Zinc oxide and NaFeEDTA 30 ppm Whole wheat our [95]
Iron
11.
- Ferrous sulphate
- Fe-EDTA 10 - 30 mg/100 g Bakery products- our Bread, Cookies,
Wheat bread
[107]
- Ferric pyrophosphate
- Ferrous fumarate 12 mg/L Milk infant formula
- FeCl310 mg Fe/100mL Yogurt
- Caesin-chilated Iron ferric chloride
25 - 50 mg Fe/kg Mozzarella cheese
- Ferrous Sulphate 15 mg/L Milk
Vitamin E
12. - Vitamin E 300 ppm (µl of Vit E/g lipid meal) Ground beef patties [98]
13. - α-tocopherol -
Β-lactoglobuline and Hen egg white protein
[108]
Vitamin D
14. - Vit. D3 emulsied in butter oil 5000 IU/100g of product Cheese, Yogurt, Ice-cream [97]
Vitamin A
15. - Retinyl acetate 257.85 µg/100 g Cookies [15]
16. - Vitamin A, palmitate iron and
Iodine
Vit A - 250 IU of vit.A/100 g
Iron - 1000 ppm
Iodine - 50 ppm Triple fortied salt [87]
17. - Retinol - O/W/O emulsion
[109]
18. - Retinol - Glyceryl behenate SLN
19. - All trans retinoic acid - 2-Hydroxypropyl-β-cyclodextrin complex
20. - Retinol - Β-Lactoglobulin complex
Folic Acid
21. - Folic acid (low methoxy pectin
and ethyl cellulose) 400 µg/g Parboiled rice [104]
22. - Folic Acid 0.05 g/100 g of our Asian noodle [110]
23. - Folate
131 - 191 µg/100g Bakery Products, Sourdough, French
loves, Potato rolls, Sandwitch.
[103]
33 - 229 µg/100g Cereal products-ours, baking n\mix,
bread mix
154 - 308 µg/100g Instant rice, Parboiled rice yellow rice,
precooked rice.
198 - 264 µg/100g
Enriched macaroni products, Spagetti, Pasta.
198 - 264 µg/100g Noodle
80 - 400 µg/100g
Ready to eat breakfast cereals(corn, oat, wheat)
40 - 120 µg/100g Cereal bars
Riboavin
24. - Riboavin - Soy protein cold set hydrogel [102]
Vitamin C
25. - Vitamin C 33 mg/100 g Ascorbic acid [101]
- Vitamin A palmitate 300 IU/100 g Vit. A palmitate
Nutrients having functional properties
26. - Ω-3 long chain PUFA
1 - 5 mg/100g Cheese, butter
[100]
20 mg/100g Spreadable fresh cheese
30 mg/100g Cheese, butter
40 - 60 mg/100g Processed cheese
27. - Curcumin 4.1 mg/mL of lecithin and Tween
80 as the surfactants and ethyl
oleate as oil phase - [111]
Journal of Hygienic Engineering and Design
88
used to enrich dierent fruit juices which undergoes
minimum heat treatments and retained maximum
quantity of vitamin C [101].
2.4.9 Vitamin B
Vitamin B1 is sensitive to heat or oxidation. The major
challenge in this context is, these are water soluble
vitamins and leaching losses are more. They are often
delivered through breakfast cereals, juices, milk, and
infant formulas. Generally enriched in food products as
vitamin B complex. There are new novel approaches for
delivery of these vitamins such as soya protein cold set
hydrogel is used to entrap vitamin B for incorporation
in food products [102].
2.4.10 Folic acid
Folic acid is soluble in water and sensitive to heat. The
RDA for folic acid is 400 µg per day [86]. Folate is used
to fortify dierent bakery products (Sourdough ban-
quettes, French loves, Buttertop breads, Italian bread,
Potato rolls, Enriched Floors (229 µg per 100g), white
breads upto 131 - 191 µg per 100g ), cereal products
(All purpose ours, wheat our, bread mix, All-purpose
baking mix upto 33-229 µg per 100g), Instant rice
(Precooked rice, parboiled rice, yellow rice, instant rice
at 154 - 308 µg per 100g), macaroni (198-264 µg per
100g), pasta, noodles (198-264 µg per 100g), ready to
eat breakfast cereals (80 - 400 µg per 100g) and cereal
bars (40 - 120 µg per 100g) [103]. Another way of deliv-
ering folic acid is addition to rice up to 400 µg per 100g
of rice and coating with edible polymers ethyl cellulose
[104].
Thus dierent combinations of heat sensitive nutrients
and their interaction with each other determine their
bioavailability. Appropriate encapsulation, Use of more
chemically stable form and novel and non-thermal pro-
cessing techniques provides desired retention levels of
sensitive nutrients in Food matrices during processing,
storage and consumption. Following table 3 explains in
details some more examples of vitamins, minerals and
bio-active compounds with respective food systems.
2.5 Recent trends in delivery of heat sensitive nu-
trients
More and more eorts are being taken by food scientist
to incorporate these sensitive nutrients in food by us-
ing newer technologies such as membrane extrusion,
vacuum impregnation. New vehicles for these nutri-
ents such as β-lactoalbumine and Hen white protein
for α-tocopherol, soy protein cold set hydrogel for ri-
boavin, milk caesinates are also developed for protec-
tion against processing conditions [112].
Also biofortication of food plants for vitamins by
using metabolic engineering is also encouraging.
Minerals fortication is done by manipulating manure
dosage during plant growth become more precise and
successful [113].
3. Conclusions
- Food contains many heat sensitive nutrients such
as vitamins, minerals, nutrients having functional
properties. Many processes during manufacturing
of food cause detrimental eects on these nutri-
ents. Among these nutrients vitamins (Vit. A,D,E,
B,C) are most susceptible for heat causes upto 80 %
destruction due to processing treatments and min-
erals get unavailable due to interaction with co-nu-
trients during the heat treatments such as pasteuri-
sation, sterilisation, ultra high temperature.
- In order to maintained the level of these sensitive
nutrients dierent approaches are applied includ-
ing process modications, fortication or encapsu-
lation. The nature of methodology depends exclu-
sively in interest of functionality of particular nutri-
ents in food irrespective of techniques.
- In case of delivery of heat sensitive nutrients
through food systems we concentrate on dierent
delivery systems such as 0/w emulsion, nano-emul-
sions, encapsulation, molecular complexes, and
powder particles with their uses in food application.
- Many recent trends are also becoming more and
more successful to prevent sensitive nutrients from
degradation such as use of: Microwave and Radio
Frequency Heating, Ohmic and Inductive Heating,
High Pressure Processing, Irradiation of Food,
Pulsed X-ray Processing, Pulsed Light processing,
Ultra-Violet Pasteurization, Oscillating Magnetic
Fields, Pulse Electric Field, Chlorine Dioxide
Processing, Low-Temperature Plasma, Ozone pro-
cessing, Dense-Phase Carbon Dioxide Processing of
Fluid Foods, Ultra-sound Processing of Food, High
Voltage Arc Discharge and bio-fortication. Thus
lots of work is to be done by food scientist to come
up with more and more ecient technology.
4. References
[1] Clydesdale F.M., Francis F.J. (1976). Pigments. In:
Fennema, O.R. (Ed.), Principles of Food Science - Food
Chemistry. Marcel Dekker, New York, pp. 417 - 430.
[2] Britton G. (1992). Carotenoids. In: Hendry G. F. (Ed.),
Natural Foods Colorants. G. F. Blackie, New York, pp. 141
– 148.
[3] Bolin H.R. (1982). Eect of processing of nutrient compo-
sition of food: fruits and fruit products. In: Rechcigl Jr. M.
(Ed.), Handbook of Nutritive Value of Processed Food.
Journal of Hygienic Engineering and Design
89
Food for Human Use, Vol. I. CRC Press, Boca Raton, FL,
pp. 310.
[4] Harris R.S. (1987). General discussion on the stability of
nutrients. In: Karmas E., Harris R. S. (Eds.), Nutritional
Evaluation of Food Processing. Van Nostrand Reinhold,
New York, pp. 4.
[5] Emilla L., Janna K., Eva Kovacikova, Martina K., Janka P.,
Kristina H. (2006). Vitamin losses: Retention during heat
treatment and continual changes expressed by mathema-
tical models. Journal of Food Composition and Analysis,
19, pp. 252 - 276.
[6] Eitenmiller R. R., Laden W. O. (1999). Vitamin A and b-ca-
rotene. Ascorbic acid. Thiamin. Vitamin B-6. Folate. In:
Eitenmiller R. R., Laden W. O. (Eds.), Vitamin Analysis for
the Health and Food Science. CRC Press, Boca Raton, FL
(pp. 15 - 19, 226 - 228, 275, 375, 411 - 465).
[7] Le Roche. (1976). Vitamin Compendium. F. Homann - La
Roche, Basle, Switzerland.
[8] Ottaway P. B. (2002). The stability of vitamins during food
processing: vitamin K. In: Henry C. J. K., Chapman C.
(Eds.), The Nutrition Handbook for Food Processors. CRC
Press, Boca Raton, FL, pp. 247 - 264.
[9] Karmas E. and Harris R. S. (1988). Nutritional Evaluation
of Food Processing, Van Nostrand Reinhold, New York.
[10] Hazell T. and Johnson I. T. (1989). Inuence of Food
Processing on Iron Availability in Vitro from Extruded
Maize-based Snack Foods. Journal of Science, Food and
Agriculture, 46, pp. 365 - 374.
[11] Johnson P. E. (1991). Eect of Food Processing and
Preparation on Mineral Utilization in Nutritional and
Toxicological Consequences of Food Processing (Friedman,
M., Ed.). Advances in Experimental Medicine and Biology,
25, pp. 125 - 128.
[12] Kapsokefalou M. and Miller D. D. (1995). Iron Speciation
in Intestinal Contents of Rats Fed Meals Composed of
Meat and Non-meat Sources of Protein and Fat. Food
Chemistry, 52, pp. 47 - 56.
[13] Heribert J. W. Watzke. (1998). Impact of processing bio-
availibility examples of minerals in foods. Trends in Food
Science and Technology, 9, pp. 320 - 327.
[14] Volden J. Borge A. I. G., Bengtsson B. G., Hansen M.,
Thygesen E. I., Wicklund T. (2008). Eect of thermal treat-
ment on glucosinolates and antioxidant-related parame-
ters in red cabbage (Brassica oleracea L. ssp. capitata f.
rubra). Food Chemistry, 109(3), pp. 595 - 605.
[15] Suresh D., Manjunatha H., Krishnapura S. (2007). Eect
of heat processing of spices on the concentrations of their
bioactive principles: Turmeric (Curcuma longa), red pep-
per (Capsicum annuum) and black pepper (Piper nigrum).
Journal of Food Composition and Analysis, Volume 20,
Issues 3 - 4, pp. 346 - 351.
[16] Job U. and Jessica K. (2006). Physical approaches for the
delivery of active ingredients in foods. Trends in Food
Science and Technology, 17, pp. 244 - 254.
[17] Corey E. J., and Cheng X. M. (1989). Chapter 1 - The Basis
for Retro-synthetic Analysis. In:The logic of chemical syn-
thesis. New York: John Wiley & Sons. pp: 1 -15.
[18] Salminen S., Ouwehand A., Benno Y., and Lee Y. K. (1999).
Probiotics: How should they be dened? Trends in Food
Science and Technology, 10(3), pp. 107 - 110.
[19] Sigler K., Chaloupka J., Brozmanova J., Stadler N., and
Hofer M. (1999). Oxidative stress in microorganisms - I.
Microbial vs. higher cells - Damages and defences in rela-
tion to cell aging and death. Folia Microbiologica, 44(6),
pp. 587 - 624.
[20] Crowe J. H., Carpenter J. F., and Crowe L. M. (1998). The
role of vitrication in anhydrobiosis. Annual review of
Physiology, 60, pp. 73 - 103.
[21] Beales N. (2003). Adaptation of microorganisms to cold
temperatures, weak acid preservatives, low pH, and os-
motic stress: A review. Comprehensive Reviews. Food
Science and Food Safety, (3), pp. 1 - 20.
[22] Crawford D., and Davies K. (1994). Adaptive response and
oxidative stress. Environmental and Health Perspectives,
10(Suppl. 10), pp. 25 - 28.
[23] De Angelis M., and Gobbetti M. (2004). Environmental
stress responses in Lactobacillus: A review. Proteomics, 4,
pp. 106 - 122.
[24] Byers T., Perry G. (1992). Dietary carotenes, vitamin C, and
vitamin E as protective antioxidants in human cancers.
Annual Review Nutrition, (12). pp. 139 -159.
[25] Serfert Y., Drusch S., Schwarz K. (2009). Chemical stabi-
lisation of oils rich in long-chain polyunsaturated fatty
acids during homogenisation, microencapsulation and
storage, Food Chemistry, (113), pp. 1106 - 11012.
[26]Mcclements D. J. , Ogawa S., Decker E. A. (2007) Production
and characterization of O/W emulsions containing catio-
nic droplets stabilized by lecithin-chitosan membranes.
Journal Agriculture Food Chemistry, 51(28), pp. 06 - 12.
[27] Mcclements D. J., Shaw L. A., Decker E. A. (2007). Spray-
dried multilayered emulsions as a delivery method for ome-
ga 3 fatty acids into food systems. Journal of Agriculture
Food Chemistry, 55(31), pp. 9 - 12.
[28] Muschiolik G.(2007). Multiple emulsions for food use.
Current Opinion in Colloid Interface Science, (12) pp.
213 - 20.
[29] Benichou A., Aserin A. A., Garti N. (2007). W/O/W double
emulsions stabilized with WPI-polysaccharide comple-
xes. Colloids Surface Physicochemistry Engineering
Aspects, (294) pp. 20 - 32.
[30] Wooster T. J., Golding M., Sanguansri P. (2008). Impact of
oil type on nanoemulsion formation and Ostwald ripening
stability. Langmuir, (24), pp. 12758 –12765.
[31] Yuan Y., Gao Y., Zhao J., Mao L. (2008). Characterization
and stability evaluation of betacarotene nanoemulsions
prepared by high pressure homogenization under various
emulsifying conditions. Food Research International.
(41). pp. 61 - 68.
[32] Bunjes H., Steiniger F., Richter W. (2007). Visualizing the
structure of triglyceride nanoparticles in dierent crystal
modication. Langmuir, (23), pp. 4005 - 4011.
Journal of Hygienic Engineering and Design
90
[33] Carlotti M. E., Sapini S., Trotta M., Battaglia L., Vione D.,
Pelizzit E. (2005). Photostability and stability over time of
retynil palmitate in an O/W emulsion in SLN introduced in
the emulsion. Journal of Dispersion Science Technology,
26, pp. 125 - 138.
[34] Buschmann H. J., Schollmeyer E. (2002). Applications of
cyclodextrins in cosmetic products: A review. Journal of
Cosmetic Science, 53, pp. 185 - 191.
[35] Davis M. E., Brewster M. E. (2004). Cyclodextrin-based
pharmaceutics: past, present and future. National Review
Drug Discovery, 3, pp. 1023 - 1035.
[36] Semo E., Kesselman E., Danino D., Livney Y. D. (2006).
Casein micelle as a natural nanocapsular vehicle for nu-
traceuticals. Food Hydrocolloids, 21, pp. 936 - 942.
[37] Tanford C. (1980). The hydrophobic eects: formation
of micelles and biological membranes. New York: John
Willey.
[38] Leser M. E. , Sagalowicz L. , Michel M. , Watzke H. J.
(2006). Self-assembly of polar food lipids. Advance Colloid
Interface Science, 123, pp. 125 - 136.
[39] Sagalowicz L., Leser E. M. (2010). Delivery systems for
liquid food products. Current Opinion in Colloid &
Interface Science. (15) pp. 61 - 72.
[40] Metaxas R. (1996). Foundations of electro heat: a unied
approach. John Wiley & Sons. Chichester, UK.
[41] Roussy G. and Pearce J. (1995). Foundations and industri-
al applications of microwaves and radio frequency elds.
New York. Wiley.
[42] Kasevich R. S. (1998). Understand the potential of radio-
frequency energy. Chem Eng Progress. pp.75 - 81.
[43] Minett P. J. and Witt J. A. (1976). Radio frequency and mi-
crowaves. Food Processing Industry, 36 - 37.
[44] Buer C. R. (1993). Microwave cooking and processing
In: Engineering fundamentals for the food scientist, Van
Nostrand Reinhold, New York.
[45] Anantheswaran D. (2000) Fundamentals of heat and
moisture transport for microwaveable food product and
process development. A. K. Datta and R. C. Anatheswaran
(eds.). Handbook of Microwave Technology for Food
Applications. Marcel Dekker, Inc. New York.
[46] Heddleson R. A. and Doores S. (1994). Factors aecting
microwave heating of foods and microwave induced
destruction of foodborne pathogens - A review. J. Food
Protect. 57(11). pp. 1025 - 1037.
[47] Kozempel M. F., Annous B. A., Cook R. D., Scullen O. J. and
Whiting R. C. (1998). Inactivation of microorganisms with
microwaves at reduced temperatures. Journal of Food
Protection 61(5). pp. 582 - 585.
[48] USA - FDA Center for Food Safety and Applied
Nutrition (2011). Kinetics of microbial inactivation for
alternative food processing technologies: ohmic and
inductive heating. < URL: http://www.fda.gov/Food/
FoodScienceResearch/SafePracticesforFoodProcesses/
ucm101246.htm. Accessed on 11 July 2013.
[49] Marcos C. K., Carolina Alves dos Santos, Soares O. M. V.
A. A. and Thereza Christina Vessoni Penna (2010). Ohmic
heating - A review. Trends in Food Science & Technology.
21, pp. 436 - 441.
[50] Rockendra G., and Balasubramaniam M. V. (2012).
Chapter 5: High-Pressure Processing of Fluid Foods. In:
Novel Thermal and Non-Thermal Technologies for Fluid
Foods, Elsevier pp. 109 - 133.
[51] Fan X., Sokorai K. J. B. (2008). Eect of ionizing radiation
on furan formation in fresh fruits and vegetables. Journal
of Food Science, 73 (2) pp. C79 - C83.
[52] Food Engineering & Ingredients (2008). Food irradiation:
a technology wasted or simply unwanted. Vol. 33, Issue 2,
pp. 16 - 19.
[53] Brendan A. N., Meixu G. (2012). Chapter - 7 : Irradiation
of Fluid Foods. In : Novel Thermal and Non-Thermal
Technologies for Fluid Foods. pp. 167 - 183.
[54] Reyes L. F., and Cisneros - Zevallos L. (2007). Electron-
beam ionizing radiation stress eects on mango fruit
(Mangifera indica L.) antioxidant constituents before and
during postharvest storage. Journal of Agriculture and
Food Chemistry, 55, pp. 6132 - 6139.
[55] Lopez-Rubira V., Conesa A., Allende A., and Artés F.
(2005). Shelf life and overall quality of minimally processed
pomegranate arils modied atmosphere packaged and
treated with UV-C. Postharvest Biology and Technology,
37, pp. 174 - 185.
[56] Codex Alimentarius General Standard on Food
Irradiation (2003). 106 - 1983, REV. 1 - 2003.
[57] USA - FDA Center for Food Safety and Applied Nutrition
(2011). Kinetics of Microbial Inactivation for Alternative
Food Processing Technologies - Pulsed X - rays.
<URL:http://www.fda.gov/Food/FoodScienceResearch/
SafePracticesforFoodProcesses/ucm105787.htm.
Accessed on 12 July 2013.
[58] Miller R., Jerey W., Mitchell D. and Elasri M. (1999).
Bacterial responses to ultraviolet light. American Society
for Microbiology. 65(8) pp. 535 - 541.
[59] USA-FDA Center for Food Safety and Applied Nutrition
(2011). Kinetics of Microbial Inactivation for Alternative
Food Processing Technologies -- Ultraviolet Light.
<URL:http://www.fda.gov/Food/FoodScienceResearch/
SafePracticesforFoodProcesses/ucm103137.htm .
Accessed on 12 July 2013.
[60] Gonzalez - Barrio R., Vidal - Guevara M. L., Tomas -
Barberan F. A., Espın J. C. (2009). Preparation of a resve-
ratrol-enriched grape juice based on ultraviolet C-treated
berries. Innovative Food Sci. Emerg. Technol. (10). pp.
374 - 382.
[61] Gomez-Lopez M. V., Koutchma Tatiana, Linden K. (2012).
Chapter 8 - Ultraviolet and Pulsed Light Processing of Fluid
Foods In : Novel Thermal and Non-Thermal Technologies
for Fluid Foods. Elsevier, pp. 185 - 223.
[62] Gomez-Lopez M. V., Ragaert P., Debeverea J., and
Devlieghere F. (2007). Pulsed light for food decontamina-
tion: A review. Trends in Food Science & Technology, (18),
pp. 464 - 473.
[63] Tran M. T. T., Farid M. (2004). Ultraviolet treatment of oran-
Journal of Hygienic Engineering and Design
91
ge juice. Innovative Food Sci. Emerg. Technol., 5, pp. 495
- 502.
[64] Walkling-Ribeiro M., Noci F., Cronin D. A., Riener J., Lyng
J. G., Morgan D. J. (2008). Reduction of Staphylococcus
aureus and quality changes in apple juice processed by ul-
traviolet irradiation, pre-heating and pulsed electric elds.
J. Food Eng., 89, pp. 267 - 273.
[65] USA-FDA Center for Food Safety and Applied Nutrition
(2011). Kinetics of Microbial Inactivation for Alternative
Food Processing Technologies - Oscillating Magnetic
Fields.
<URL:http://www.fda.gov/Food/FoodScienceResearch/
SafePracticesforFoodProcesses/ucm103131.htm.
Accessed on 11 July 2013.
[66] Pothakamury U. R., Barbosa-Cánovas G. V., and Swanson
B. G. (1993). Magnetic-eld inactivation of microorgani-
sms and generation of biological changes. Food Technol.,
47(12) pp. 85 - 93.
[67] Barbosa-Cánovas G. V., Gongora-Nieto M. M., and
Swanson B. G. (1998). Nonthermal electrical methods in
food preservation. Food Science International, 4(5) pp.
363 - 370.
[68] Morales-de la Peña M., Salvia-Trujillo L., Rojas-Graü M. A.,
and Martín-Belloso O. (2010). Impact of high intensity pul-
sed electric eld on antioxidant properties and quality pa-
rameters of a fruit juice-soymilk beverage in chilled storage.
LWT Food Science and Technology, 43, pp. 872 - 881.
[69] Morales-de la Peña M., Salvia-Trujillo L., Rojas-Graü M.
A., and Martín-Belloso O. (2010). Isoavone prole of a
high intensity pulsed electric eld or thermally treated
fruit juice-soymilk beverage stored under refrigeration.
Innovative Food Science & Emerging Technologies,
doi:10.1016/j.ifset.2010.08.005.
[70] Wan J., Coventry J., Swiergon P., Sanguansri P., and
Versteeg C. (2009) Advances in innovative processing te-
chnologies for microbial inactivation and enhancement of
food safety - pulsed electric eld and low-temperature plas-
ma Trends. Food Science & Technology, (20), pp. 414 - 424.
[71] Food Engineering & Ingredients. (2012). A tale of two te-
chnologies: How innovative processing methods can help
keep businesses competitive. Volume 37, pp. 11 - 14.
[72] Gomez-Lopez M. V., Rajkovic A., Ragaert P., Smigic N.,
and Devlieghere F. (2009) Chlorine dioxide for minimally
processed produce preservation: A review. Trends in Food
Science & Technology, (20) pp. 17 - 26.
[73] Patil S., and Bourke P. (2012) Chapter 9 - Ozone Processing
of Fluid Foods. Novel Thermal and Non-Thermal
Technologies for Fluid Foods. Elsevier Inc., pp. 225 - 261.
[74] Barboni T., Cannac M., and Chiaramonti N. (2010). Eect
of cold storage and ozone treatment on physicochemical
parameters, soluble sugars and organic acids in Actinidia
deliciosa. Food Chemistry, 121(4), pp. 946 - 951.
[75] Perez A. G., Sanz C., Rios J. J., Olias R., and Olias J. M. (1999).
Eects of ozone treatment on postharvest strawberry qua-
lity. Journal of Agricultural and Food Chemistry, 47(4),
pp. 1652 - 1656.
[76] Barth M. M., Zhou C., Mercier J., and Payne F. A. (1995).
Ozone storage eects on anthocyanin content and fungal
growth in blackberries. Journal of Food Science, 60(6),
pp. 1286 - 1288.
[77] Ferrentino G., Balaban O. M. (2012) Chapter 10 - Dense-
Phase Carbon Dioxide Processing of Fluid Foods. Novel
Thermal and Non-Thermal Technologies for Fluid Foods,
Elsevier Inc., pp. 263 - 303.
[78] Chen J., Zhang J., Feng Z., Song L., Wu J., and Hu X.
(2010). Changes in microorganism, enzyme, aroma of
Hami melon (Cucumis melo L.) juice treated with dense
phase carbon dioxide and stored at 4 °C. Innovative Food
Science & Emerging Technologies. Volume 11, Issue 4,
pp. 623 - 629.
[79] Tiwari K. B. and Mason J. T. (2012). Chapter - 6: Ultrasound
Processing of Fluid Foods. Novel Thermal and Non-Thermal
Technologies for Fluid Foods. Elsevier Inc., pp. 135 - 165.
[80] Rawson A. Patras B. K. Tiwari F. N., Koutchma T., Brunton
N. (2011). Eect of thermal and non-thermal processing
technologies on the bioactive content of exotic fruits and
their products: Review of recent advances. Food Research
International, (44), pp. 1875 - 1887.
[81] Rawson A., Tiwari B. K., Patras A., Brunton N., Brennan
C., Cullen P. J., O’Donell C. (2011). Eect of thermosonica-
tion on bioactive compounds in water-melon juice. Food
Research International, Volume 44, Issue 5, pp. 1168 -
1173.
[82] Edebo L., Selin I. (1968). The eect of pressure shock-wa-
ve and some electrical quantities in the microbicidal ef-
fect of transient electric arcs in aqueous systems. J. Gen.
Microbiol., 50, pp. 253 - 259.
[83] Palaniappan S., Richter E. R. and Sastry S. K. (1990).
Eects of electricity on microorganisms: A review. J Food
Process Preserv., 14, pp. 393 - 414.
[84] Barbosa-Canovas G. V., Gongora-Nieto M. M.,
Pothakamury U. R. and Swanson B. G. (1999). Preservation
of foods with pulsed electric elds. Academic Press Ltd.
London.
[85] Gilliland S. E., and Speck M. L. (1967). Inactivation of mi-
croorganisms by electrohydraulic shock. Appl Microbiol.,
15(5). pp. 1031 - 1037.
[86] WHO & FAO (2004). Chapter 2 - Vitamin A. In Vitamin and
mineral requirements in human nutrition. Second edition.
World Health Organization and Food and Agriculture
Organization of the United Nations, ISBN: 9241546123.
[87] Rutkowski K., Diosady L. L. (2006). Vitamin A stability in
triple fortied salt. Food Research International, 40, pp.
147 - 152.
[88] Masood S., Muhammad U., Muhammad S., Muhammad
T. (2007). Bioavailability and storage stability of vitamin
A forticant (retinyl acetate) in fortied cookies. Food
Research International, 40, pp. 1212 - 1219.
[89]
Caceres E., Garcıa M. L., Selgas M. D. (2005). Design of a new cooked
meat sausage enriched with calcium. Meat Science, 73, pp. 368 - 377.
[90] Barrera C., Betoret N., Corell P. F. (2009). Eect of osmotic
dehydration on the stabilization of calcium-fortied apple
Journal of Hygienic Engineering and Design
92
slices (var. Granny Smith): Inuence of operating variables
on process kinetics and compositional changes. Journal of
Food Engineering, 92, pp. 416 - 424.
[91] Romanchik-Cerpovicz E. J. (2007). Fortication of All-
Purpose Wheat-Flour Tortillas with Calcium Lactate,
Calcium Carbonate, or Calcium Citrate Is Acceptable.
Journal of The American Dietetic Association, 107, pp.
506 - 509.
[92] Singh G., Kasiviswanathan M. (2008). Inuence of calcium
fortication on sensory, physical and rheological characte-
ristics of fruit yogurt. LWT, 41, pp. 1145 - 1152.
[93] Rasyid F., and Hansen P. M. T. (1991). Stabilization of soy
milk fortied with calcium gluconate. Food Hydrocolloids,
Vol-A No.5, pp. 415 - 422.
[94] Chanakan P., Benjavan R., Ismail C., Longbin H. (2010).
Zinc fortication of whole rice grain through parboiling
process. Food Chemistry, 120, pp. 858 - 863.
[95] Saeed A., Anjum F. M., Salim M. A., Kalsoom F. (2008).
Eect of fortication on physico-chemical and microbi-
ological stability of whole wheat our. Food Chemistry,
110, pp. 113 - 119.
[96] Katarzyna W., Krystyna S. (2008). The application of
wheat bre and soy isolate impregnated with iodine salts
to fortify processed meats. Meat Science, 80, pp. 1340 -
1344.
[97] Syed A., Reinhold V., Derick R. (2008). Vitamin D3 forti-
cation and quantication in processed dairy products.
International Dairy Journal, 17, pp. 753 - 759.
[98] Wills M. T., Mireles DeWitt A. C., Sigfusson H. (2007).
Improved antioxidant activity of Vitamin E through solubi-
lisation in ethanol: A model study with ground beef. Meat
Science, 76, pp. 308 - 315.
[99] Hayes K. C., Pronczuk A., and Perlman D. (2001). Vitamin
E in fortied cow milk uniquely enriches human plasma
lipoproteins. The American Journal of Clinical Nutrition,
(74) pp. 211 - 218.
[100] Wojciech K., Jenny W. (2007). Sensory quality of dairy
products fortied with sh oil. International Dairy
Journal, 17, pp. 1248 - 1253.
[101] Ilic D. B., and Ashoor S. H. (1987). Stability of Vitamins A
and C in Fortied Yogurt. Journal of Dairy Science, 71.
pp. 1492 - 1498.
[102] Anne M., Gabriel E. R., Muriel S. (2009). Soy protein cold-
set hydrogels as controlled delivery devices for nutraceu-
tical compounds. Food Hydrocolloids, (23) pp. 1647
- 1653.
[103] Jeanne I. R., Carol M. W., Gerry A. (2000). Total folate in
enriched cereal-grain products in the United States fol-
lowing fortication. Food Chemistry, 70. pp. 275 - 289.
[104] Ashok K. S., Jayashree A., Janet L. (2003). Edible coating
materials-their properties and use in the fortication of
rice with folic acid. Food Research International, 36. pp.
921 - 928.
[105] Singh G., Arora S., Sharma G. S., Sindhu J. S., Kansal
V. K., Sangwan R. B. (2007). Heat stability and calci-
um bioavailability of calcium-fortied milk. LWT, (40).
pp.625 - 631.
[106]Diosadya L. L., Albertib J. O., Venkatesh M. M. G. (2002).
Microencapsulation for iodine stability in salt fortied
with ferrous fumarate and potassium iodide. Food
Research International, 35, pp.635 - 642.
[107]Martınez N., Camachoa J., Martınez L., Martınez M,.
Fitoa P. (2002). Iron deciency and iron fortied foods-A
review; Food Research International, 35, pp. 225 - 231.
[108] Somchue W., Sermsri W., Shiowatana J., Siripinyanond
A. (2009). Encapsulation of a-tocopherol in protein-ba-
sed delivery particles. Food Research International, 42,
909 - 914.
[109] Loveday M. S. and Singh H. (2008). Recent advances in
technologies for vitamin A protection in foods. Trends in
Food Science & Technology, 19, pp. 657 - 668.
[110] Cheung F. H. R., Hughes G. J., Marriott J. P., Small M. D.
(2009). Investigation of folic acid stability in fortied ins
tant Asian noodles by use of capillary electrophoresis.
Food Chemistry, 112, pp. 507 - 514.
[111] Chuan-Chuan L., Hung-Yin L., Hsu-Chih C., Ming-Wen
Y., Mei-Hwa L. (2009). Stability and characterisation
of phos pholipid-based curcumin-encapsulated micro-
emulsions. Food Chemistry, 116, pp. 923 - 928.
[112] Livney D. Y. (2010). Milk proteins as vehicles for bioac-
tive. Current Opinion in Colloid & Interface Science,
(15), pp. 73 - 83.
[113] Johns T., Eyzaguirre B. P. (2006) Bioforti Wcation, biodi
versity and diet: A search for complementary applica-
tions against poverty and malnutrition. Food Policy,
(32). pp. 1 - 24.
