In the field of food safety, hurdle technology is a method of ensuring the safety of foods by eliminating or controlling the growth of pathogens. It is a gentle and effective preservation technique used for the inactivation of microorganisms to make food safe for public consumption and extend their shelf life.
4. INTRODUCTION
• Food qualities can be disturbed by the growth of spoilage microorganisms and food safety is
threatened by the presence of pathogenic microorganisms that can cause food infection and food
intoxication (Skovgaard, 2004).
• The foodborne threat makes food safety important not only for a public health concern but also for
its roles production economy and marketplace. (Khan et al., 2017)
• Microorganisms account for more than 70 % of food spoilage, ensuring safety and stability of foods
depends on the right choice of food preservation methods that will ensure microbial and chemical
safety and maintain nutritional and sensory qualities. (Abdullahi et al., 2016b)
• The traditional methods of slowing or eliminating microorganisms in food were proven to solve
food quality and safety-related problems but was also reported to affect food qualities through the
destruction of essential nutrients and the slashing of organoleptic qualities (Khan et al., 2017). To
minimize the negative effects of traditional preservation methods it’s imperative to use two or more
hurdles in combination.
• The aim of combining different preservation methods or techniques is to preserve the quality and
safety of food during an extended storage period (Skovgaard, 2004).
5. HURDLE TECHNOLOGY
• Hurdle technology is a multiple-barrier technology that employed multiple
preservative measures, that are strategically applied, to efficiently control
the growth of microorganisms in food (Yuan, 2003).
• The approach to hurdle technology involves combining traditional and novel
technologies to control microbial growth in food (Ravishankar and Maks,
2007).
• Smart combinations of different hurdles ensure microbial safety, minimize
energy consumption, reduce emissions, increase profit and affordability and
increase overall quality.
• In addition to preservation effects, hurdles used in food can improve
acceptability (Abdullahi et al., 2016b) and nutritional quality.
6. NEED & SIGNIFICANCE
• The increasing demand for fresh, qualitative,
microbiologically safe and stable foods stimulated
the use of hurdle technology in food preservation
(Ghrairi et al., 2012; Guerrero et al., 2017).
• An important current trend adopted by hurdle
technology ensures the delivery of less preserved
foods at lower levels. This approach ensured higher
quality foods that are more natural, contain fewer
additives, received simple treatments and are
nutritionally healthier than foods preserved through
conventional methods.
• Consumer demand for foods with fewer changes in
nutrients and sensory qualities also promoted hurdle
technology in recent years. (Pal et al., 2017)
• This approach saves money, energy and several
resources and reduces economical losses.
8. • Uniform and stable ecosystem for successful
survival of cells in the internal status of
organisms.
• Food preservation can be achieved by
deliberately disturbing the homeostasis
mechanisms through preservative factors or
hurdles.
• Organisms have a strong tendency to
maintain internal environment stable, for the
balanced homeostasis conditions.
• Energy restrictions may be given by
anaerobic conditions like reduced aw , pH
and Eh with modified atmosphere or
vacuum packaging.
• Auto-sterilization in food products could be
achieved by metabolic exhaustion, which
leads to the death of germinated spores and
thus ensuring the success of hurdle
technology.
• Microorganisms in hurdle technology foods try
every possible repair mechanism for their
homeostasis. By doing this, they completely
use up their energy and die, that leads to auto-
sterilization of foods.
• There are number of different kinds of
bacteria, molds, yeast which overcome and
sustain the high temperature treatment.
HOMEOSTASIS
METABOLIC
EXHAUSTION
9. • Due to the generation of shock proteins, some
bacteria become more and more
resistant/virulent under stress.
• The stress shock proteins are nothing but a
family of proteins that are produced by cells in
response to exposure to stressful conditions,
induced by heat, pH, aw, ethanol, oxidative
compounds, cold, UV light and starvation.
• Simultaneous exposure to different stresses will
require energy-consuming synthesis of several or
at least much more protective stress shock
proteins, which in turn may cause the
microorganisms to become metabolically
exhausted.
• If the types of hurdles in foods are in
right combination, the homeostasis of
the microorganisms could be disturbed
resulting in a synergistic effect.
• Activation of stress shock proteins and
repairing of homeostasis is more
difficult.
STRESS
REACTIONS MULTI-TARGET
PRESERVATION
10. FACTORS AFFECTING
The most important factors used in the hurdle technology are the
intrinsic factors (aw, pH, Eh, and chemicals) the extrinsic factors
(temperature of storage and gas atmosphere), and the processing
factors (heating, drying, fermentation) (Hamad, 2012).
Novel physical factors such as hydrostatic pressure, pulsed electric
fields, ultrasound, ozone, pulsed light, and ultraviolet light, among
others, are now used to replace the deleterious processes such as
thermal processing (Guerrero et al., 2017).
Hurdle technology plays an important role in the production of
various ready-to-eat and ready-to-cook stable products (Tripathi et
al., 2011).
11. POTENTIAL HURDLES
Carbon dioxide,
ethanol, Low Ph, Low
redox potential, Low
water activity, Organic
acids, Ozone, Salt,
smoking, sodium
nitrite/nitrate, sodium
or potassium sulfite,
spices and herbs,
surface treatment
agents.
PHYSICAL
HURDLES
High temperature (Blanching,
pasteurization, sterilization,
evaporation, extrusion, baking,
frying), Low temperature
(chilling, freezing),
Electromagnetic energy
(microwave, radio frequency,
pulsed magnetic fields, high
electric fields), Ultra-high
pressures, Ultrasonication,
Modified atmosphere and
packaging films (including
active packaging, edible
coatings).
PHYSICO
CHEMICAL
HURDLES
MICROBIALLY
DERIVED
HURDLES
Antibiotics,
bacteriocins,
competitive flora
(Nisin, bacteriocins,
H2O2), protective
cultures,
Microfiltration,
Bacterio fugation,
Ripening (ageing).
17. In Dairy Industry
● Although thermal processing is still the technology most commonly used for
inactivating microorganisms and enzymes in general processed food
products, and specifically beverages, it is well known that sensory and
nutritional compounds are modified as a result.
● In addition, the application of non-thermal processes to ensure microbial
inactivation of milk products with reduced effects on nutritional and quality
parameters is un-der study, especially pulsed electric fields (PEFs) and high
hydrostatic pressure (HHP),combined with the addition of natural bioactive
compounds of animal (fatty acids), microbial (probiotics and prebiotics) and
vegetable origin (essential oils, isoflavones) (Chipurura & Muchuweti, 2010)
● With regard to milk products, the microbiological preservation of newly
formulated milk-based beverages has been extensively studied by Martinez,
Rodrigo and co-workers for some years (2006-2013) by means of
supplementation with natural antimicrobials, alone or in combination with
other non-thermal technologies.
18. Hurdle Technology applied to
MILK BEVERAGES
● In the area of guaranteeing milk beverage safety and quality, for improving the
organoleptic and nutritional value of thermally treated beverages and preserving
the microbiological stability of pasteurized milk-based beverages during
refrigerated shelf life. In this regard, non-thermal technologies such as PEFs and
HHP have been studied in combination with natural antimicrobials to enhance
microbial inactivation levels.
● Pina-Pérez, Martinez,et al. (2012) studied the combined effect of PEFs and
cinnamon, added as an ingredient to a milk beverage in order to achieve suitable
reduction levels while avoiding impairing the quality of the pasteurized milk.
According to the results obtained by Pina-Pérez, Martinez, et al. (2012), at all the
treatment conditions studied (electric field(E) 15e35 kV/cm; treatment time
60e3000 ms), a synergistic additional effect close to 1 log10 cycle was observed,
attributed to a combination of non-thermal processing of skim milk and direct
supplementation with 1%, 2.5% and 5% (w/v) of cinnamon powder.
19.
20. ADVANTAGES OVER OTHER
PRESERVATION TECHNIQUES
• The main advantage of this technique is affinity to overcome the ability of
microorganisms in developing resistance to conventional preservation methods
since this technique using combination of different preservation technique
which acts synergistically by hitting different targets within the cell of the
spoilage microorganism.
• Basically, in this technique, hurdles are use at lower concentrations this prevent
the undesirable sensory changes and also provide the lower production cost and
save energy.
• Another advantage of this technique is using natural preservatives in
combination with synthetic preservatives, this also lower the risk associated with
using synthetic preservatives at high concentration.
• Possibility of increasing shelf-stable foods; because food preserved by combined
methods (hurdles) remains stable and safe even without refrigeration, and is high
in sensory and nutritive value due to the gentle process applied.
21. FUTURE ASPECTS & CHALLENGES
• Challenges regarding even distribution of some hurdles in the food matrices, their influence on flavor
and color, possible resistance of microorganisms to new hurdles, and destruction of some hurdles by
processing conditions (Søltoft-Jensen and Hansen, 2005).
• Another important challenge is understanding the stress response behavior of the target
microorganisms, some microorganisms developed defense mechanisms when they are under stress and
they become more resistant when they recover.
• Process uniformity is another factor that ensures the effectiveness of combined treatment.
• The future of food preservation will be based on a smart combination of different antimicrobial factors
that will guarantee microbiological safety and stability while keeping organoleptic qualities at a
maximum (Lucke, 2003).
• The use of innovative preservation methods in combination with less intense treatments is fast gaining
attention (Alexandre et al., 2012).
• Predictive microbiological modeling can be used to forecast how microbes behave under different
hurdle combinations, this is an important approach that can be used to test how microbes would grow
in new food recipes (Ngadi et al., 2012).
• As research into hurdle and novel preservation techniques continues, a torrent of an endless number of
hurdle combinations specifically customized for precise purposes are expected (Ngadi et al., 2012)
22. CONCLUSION
The use of hurdle technology in food preservation changes the manner of food
preservation in recent years. More natural foods are consumed now, and nutrients
and organoleptic qualities suffer less.
The safety of many foods was improved, and the storage life of many perishable
foods
was extended. Resistance microorganisms are suffering, and many can be
eliminated by a smart combination of different preservatives.
Development of new preservation techniques using new hurdles and understanding
their properties when combined with existing preservation techniques will open new
areas of research.
Future researches should be focused on the preservative effects of hurdles at the
industrial scale to understand the effectiveness of the technology on a commercial
scale.