1. HURDLE TECHNOLOGY

2. 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.

3. Competative microorganisms Preservatives
Commonly used hurdles
High Temperature
Low temperature
Low water activity
Acidicity
Low redox potential
Competative microorganisms
Preservatives

4. Potential Hurdles for use in fish preservation
Physical hurdles
Microbially derived hurdles
Physico chemical hurdle
Miscellaneous hurdles

5. Physico chemical hurdle
Physical hurdles
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
High Temperature: Sterilization, Pasteurization and Blanching
Low temperature : Chilling and Freezing
Ultraviolet radiation
Ionizing radiation
Electromagnetic energy ( Microwave energy, Radio frequency energy, Oscillating magnetic field pulses and High electric field pulses)
Photodynamic inactivation
Ultra high pressure
Ultrasonication
Packaging film (Plastic, multi layer, active coating and edible coating)
Modified atmospheric packaging (Gas packaging, Vacuum packaging, Moderate vacuum and active packaging)
Aseptic packaging
food microstructure

6. Microbially derived hurdles
Miscellaneous hurdles
Competitive flora
Protective cultures
Bacteriocins
Antibiotics
Monolaurin
Free fatty acids
Chitosan
Chlorine

7. Advantages and disadvantages of Hurdle technology
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
Inconsistency of inhibitory effect
Decompose during storage