hurdle technology. hurdle technology advocates the deliberate combination of existing and novel...
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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
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
•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
Physical hurdles Physico chemical hurdle
Competitive flora
Protective cultures
Bacteriocins
Antibiotics
Monolaurin
Free fatty acids
Chitosan
Chlorine
Microbially derived hurdles Miscellaneous hurdles
Hurdle Advantage Disadvantage
Low dose irradiation In active vegetative microorganismsIn package treatment Additional shelf life
Microbial spores resistantConsumer resistanceCapital 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 resistantPossibility of textural changes
Chemicals (pH, salt, spices) Low cost Impact on sensory quality
Protective cultures Effective against spore formers Cost of handling culturesHeat sensitivity
Bacteriocins Many are heat stableEffective against spore formers
Inconsistency of inhibitory effectDecompose during storage
Advantages and disadvantages of Hurdle technology