2. In developing countries this is usually due to a
limited food supply, but ID also represents a
public health problem in some industrialized
countries where consumers try to consume a
preventive diet, i.e. reducing food intake or the
consumption of specific foods that may lead to
a decrease of micronutrient intake and status.
Because iron is present in many foods, and its
intake is directly related to energy intake, the risk
of deficiency is highest when iron requirements
are greater than energy needs. This situation
happens in infants and young children, adoles-cents,
and in menstruating and pregnant women
(Zimmermann and Hurrell, 2007). The fortifica-tion
of foods with iron is more difficult than it is
with other nutrients, such as iodine in salt and
vitamin A in cooking oil. Most bioavailable iron
compounds are soluble in water or dilute acid,
but often react with other food components to
cause off-flavors and color changes, fat oxidation,
or both (Hurrell, 2002). The choice of the food that
is going to be a vehicle for the iron compound is
as important as the choice of the form of iron
used in enrichment programs. Bread and bakery
products made with cereal flours are a staple
food in many countries and are therefore of
global importance in international nutrition
(Cauvain, 2004). Although iron-fortified wheat
flour has existed in the market for many years,
and the market for functional bakery foods is
continuously increasing, to date the efforts of
industries devoted to innovative formulations/
technologies have not overcome the most im-portant
hurdle for consumers’ acceptance of iron
fortified foods, that is the negative effect of the
added iron on the sensory quality of bakery
products. Consequently iron-fortified foods are
usually rejected by consumers due to unacceptable
changes of their sensory characteristics. According
to Regulation (EC) 1924/2006 regarding nutri-tional
health claims made on foods, if it is it
claimed that a product is a “source of iron”, that
means it contains at least a significant amount of
2.10 mg Fe per 100 g of product. If the nutritional
claim indicates “high iron content”, that means
the product contains at least twice the value of
the source.
On the other hand, contact with the other com-ponents
of bread can reduce intestinal iron ab-sorption.
F U N C T I O N A L B A K E R Y P R O D U C T S 9
For example, high levels of phytic acid
in cereals must be taken into account, and their
sensitivity to fat oxidation during storage, par-ticularly
if they contain added highly bioavailable
compounds such as ferrous sulfate.
The breadmaking process also has important
effects on iron availability. Bakery processes
include aggressive mediums for iron compounds,
e.g. an acidic pH, temperature in the oven, humid-ity,
etc., that oxidize iron compounds, reducing
its bioavailability. Microencapsulation technology
appears to be a solution in this case.
Moreover many questions still remain open on the
iron bioavailability of fortified foods. A report
by the Scientific Advisory Committee on Nutrition
(SACN) on Iron and Health (2010) evidenced
that although iron-fortified foods make a sub-stantial
contribution to intake, the evidence
from efficacy trials suggests that foods such as
flour fortified with elemental iron are unlikely to
make a valuable contribution to increasing iron
stores (owing to low solubility and low intestinal
uptake).
As the SACN recommended, there is a need for
research studies to study the extent to which
foods fortified with iron, e.g., cereals and cereal
products, contribute to the supply of absorbed
iron and to achieving adequate iron status,
particularly in vulnerable groups. The impact of
the different variables of bakery food processing
must be clarified in order to formulate and
produce iron-enriched bakery products having
an actual possibility of ameliorating iron status.
Introduction
Based on this information, a consortium formed
by ainia together with European Universities,
and small and medium bakery companies from
Poland, Italy and Spain led by the University of
Bologna, started a project named “BAKE4FUN”
(Innovative biotechnological solutions for the
production of new bakery functional products).
One of the project’s main objectives is to design,
validate and develop innovative health-promoting
bakery products by using innovative technologies
that may increase the stability and bioavailability
of iron, without losing sensorial quality. The
S C I E N C E
3. ++ table 1: Type of encapsulates
Type of encapsulates Shape Morphology
Reservoir Type
(core-shell type)
Spherical The active agent is in the cor e of the capsule
Matrix type Asymmetrical The active agent is distribuited in the wall
source: ainia ++ table 2: Micr oencapsulation processes classification
main technological hurdle in the production of
novel iron-fortified bakery products is repre-sented
by giving the new products sensorial and
palatability characteristics allowing them to be
used by the general population.
Microencapsulation technology is a good option
to increase iron stability and bioavailability,
avoiding sensorial changes that may provoke a
rejection of bakery food products. Encapsula-tion
may be defined as a process to entrap one
substance with another substance, thereby pro-ducing
particles with diameters from few nm up
to few mm. The substance that is encapsulated
may be called the core material or active agent.
The substance that is encapsulating may be
called the shell, coating, wall or matrix. The car-rier
encapsulating material for food products or
processes should be food grade and must be able
to form a barrier for the active agents and its
surroundings (Jin et al., 2008). Two main types
of encapsulates might be distinguished (table 1).
Possible benefits of microencapsulated ingredi-ents
within the food industry can be:
+ Improved stability in the final product and
during processing (i.e. less evaporation of vola-tile
material. It can be also in the surface of the
capsule
active agents and/or no degradation or
reaction during food processing).
+ Controlled release (differentiation, release by
the right stimulus).
+ Superior handling of the active agent (e.g.
conversion of liquid active agents into a powder,
which might be dust free, free flowing and
might have a more neutral smell).
+ Immobility of active agents in processing
systems.
+ Adjustable properties of active components
(especially odor profile, particle size, structure,
color).
Microencapsulation techniques can be classified
into chemical processes and mechanical or
physical processes (table 2). These labels can be
somewhat misleading, as some processes classi-fied
as mechanical might involve or even rely
upon a chemical reaction, and some chemical
techniques rely on physical events.
A number of different processes are involved in
the release of food ingredients from microcap-sules.
The more significant steps in this release
mechanism are: dissolution/erosion/permeation
Type of encapsulates Methods
Chemical + Coacervation
+ Interfacial or in-situ polymerization
+ Emulsion-solvent evaporation
+ Molecular encapsulation
Physical-chemical + Encapsulation by supercritical fluids: co-pr ecipitation, inclusion
complex
Physical or mechanical + Spray drying
+ Spray chilling or cooling
+ Extrusion coating
+ Fluidized bed
source: ainia
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