Transcript Hurdle technology File

HURDLE TECHNOLOGY
HURDLE TECHNOLOGY
Hurdle technology advocates the deliberate combination of existing and
novel preservation techniques in order to establish a series of preservative
factors (hurdles) that any microorganisms should not be able to overcome.
Consumer demand for more natural and fresh-like foods, which urges food
manufacturers to use only mild preservation techniques (e.g. refrigeration,
modified-atmosphere packaging and biopreservation), which makse the
preservation even greater difficult task.
Commonly used hurdles
•High Temperature
•Low temperature
•Low water activity
•Acidicity
•Low redox potential
•Competative microorganisms
•Preservatives
Potential Hurdles for use in fish preservation
Physical hurdles
Physico chemical hurdle
Microbially derived hurdles
Miscellaneous hurdles
Physical hurdles
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High Temperature: Sterilization,
Pasteurization and Blanching
Low temperature : Chilling and
Freezing
Ultraviolet radiation
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Ionizing radiation
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Electromagnetic energy ( Microwave
energy, Radio frequency energy,
Oscillating magnetic field pulses and
High electric field pulses)
Photodynamic inactivation
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Ultra high pressure
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Ultrasonication
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Packaging film (Plastic, multi layer,
active coating and edible coating)
Modified atmospheric packaging (Gas
packaging, Vacuum packaging,
Moderate vacuum and active
packaging)
Aseptic packaging
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food microstructure
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Physico chemical hurdle
•Low water activity (aw)
•Low pH & redox potential (Eh)
•Salt
•Nitrite
•Nitrate
•Carbon dioxide
•Oxygen
•Ozone
•Organic acids
•Lactic acid
•Lactate
•Acetic acid
•Acetate
•Ascorbic acid
•Sulphate
•Smoking
•Phosphates
•Glucono lctones
•Phenols
•Chelators
•Surface treatment agents
•Ethanol
•Propyle glycol
•Maillard reaction products
•Spices & Herbs
•Lactoperoxidas & Lysozyme
Microbially derived hurdles
Miscellaneous hurdles
 Competitive flora
 Monolaurin
 Protective cultures
 Free fatty
acids
 Bacteriocins
 Antibiotics
 Chitosan
 Chlorine
Advantages and disadvantages of Hurdle technology
Hurdle
Advantage
Disadvantage
Low dose irradiation
In active vegetative
microorganisms
In package treatment
Additional shelf life
Microbial spores resistant
Consumer resistance
Capital costs
Modified atmospheric packaging
Reduces oxidation and microbial
spoilage
No significant effect on pathogen
Freezing
Longer shelf life
Thawing required
Higher costs
High hydrostatic pressure
In- package treatment
Spores resistant
Possibility of textural changes
Chemicals (pH, salt, spices)
Low cost
Impact on sensory quality
Protective cultures
Effective against spore formers
Cost of handling cultures
Heat sensitivity
Bacteriocins
Many are heat stable
Effective against spore formers
Inconsistency of inhibitory effect
Decompose during storage