HURDLE TECHNOLOGY HURDLE TECHNOLOGY Hurdle technology advocates the

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 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 Physico chemical hurdle • Low water activity (aw) • Low p. H & 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 (p. H, 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