Hurdle technology

hurdles in food preservation

1. Hurdle Technology By Kulwinder Kaur

2. Introduction What is Hurdle Technology ? Combination of preservation/ process/ methods/ techniques which employ the use of two or more hurdles or barrier to spoilage micro-organism to produce safe, shelf stable and nutritious food. Also known as Barrier technology Used for shelf stable food products and IMF For example : In Jam, heat, high solid content and acidification In vegetable fermentation, salt and acidification Leistner - Father of Hurdle Technology (1976)

3. Need of hurdle technology Consumer prefers fresh or minimally processed foods of high quality, more “natural”, produced with the minimum amount of additives, microbiologically safe, nutritious and healthy.

4. Significance of Hurdle Technology Improvement in product quality and microbial safety. Combined factors act synergistically Saving money, energy and several resources Reduce economic losses. Applicable in both large and small industries Food remain safe and stable even without refrigeration.

5. Examples of hurdles

6. Sequence of hurdle in fermented sausage and ripened cheese.

7. Principles of Hurdle Technology Homeostasis

8. Homeostasis Uniform and stable ecosystem for successful survival of cells in the internal status of organisms. Organisms have a strong tendency to maintain internal environment stable, for the balanced homeostasis conditions. Food preservation can be achieved by deliberately disturbing the homeostasis mechanisms through preservative factors or hurdles. Energy restrictions may be given by anerobic conditions like reduced a w , pH and E h with modified atmosphere or vacuum packaging

9. Metabolic Exhaustion

10. Stress Reactions

11. Multi target preservation

12. POTENTIAL HURDLES IN FOOD INDUSTRY

13. Physical Hurdles Heat Processing- To kill/ destroy microorganisms and/ or enzymes Heating in hermetic ceiling avoid recontamination Not applicable Temperature 60-85°C Temperature At or above 100°C

14. Storage temperature: Mainly Chilling and freezing during storage

15. Radiation – Process of using a radiation frequency of 10 9 MHz or above

16. Electro-magnetic energy (EME)- results from high voltage electric fields

17. Ultra high pressure process- 3000 bar and above to inactivate enzymes and microbes Ultra Sonication- vibrations between 18kHz to 500 MHz

18. Packaging Vacuum Packaging Moderate vacuum packaging Active Packaging Modified atmosphere packaging Controlled atmosphere packaging Aseptic packaging Edible coating

19. Physico-chemical hurdles

20. Microbially derived hurdles Competitive flora: like Nisin, Bacteriocins, H 2 O 2 Microfiltration Bacteriofugation Ripening (aging)

21. Applications of Hurdle Technology

22. Fruits and Vegetables Shorter shelf life due to high in moisture content and water activity High respiration rate Preservation: inhibition of microbial load, reduction in respiration rate and ethylene biosynthesis by low temperature or modified storage, surface disinfection, thermal and non thermal treatments, active and intelligent packaging etc.

23. Types of hurdle Example Limitations Surface Disinfectants Chlorine/ H2O2/ Off flavour development, anthocyanin degradation Ozone treatment Health hazards, environment pollution Non thermal processing High voltage electric field, RF, Ohmic heating, dielectric heating, ultrasound processing Not effective against microorganisms Pressure treatment Hydrostatic pressure High cost Active packaging MAP, CAP, CAS Fermentation and off flavour development due to disbalance in atmosphere Antimicrobial films Edible or bio films coating Poor mechanical and barrier properties, high cost Storage temperature Refrigeration, freezing Chilling injuries For example: Multitarget preservation methods can be used to achieve desirable microbial safety and quality of fruits and vegetables.

24. Meat Industry

25. Fish preservation Fish products can be preserved by applying conventional technologies along with modern technologies. For example: In IMF ; acidification along with addition of humectants In HMF: natural antimicrobial agents during osmotic treatment Heat treatment + salting+ acidification in minced fish can increase shelf life upto 15 days at 15°C

26. Dairy industry Use of thermal pasteurization for processing of milk Pulsed electric fields (PEF) and microfiltration (MF) allow gentle milk preservation at lower temperatures and shorter treatment times for similar, or better, microbial inactivation and shelf stability when applied in a hurdle approach .

27. Paneer is highly perishable with shorter life upto 3 days (at low temperature) and one day ( at room temperature). Brown Peda is khoa based Indian delicacy. Shelf life can be extended using hurdles like surface treatment, reduction in water activity, acidification (pH 5.0) and various packaging techniques (vacuum or MAP).

28. Limitations of Hurdle technology

29. Limitations of Hurdle technology Synergistic effect of combined hurdles were found to weak in laboratory tests as to have no significance for practical food preservation Application of this concept is largely restricted to meat sector Detailed understanding about how stress causing mechainsms triggered and proceed for desired microbial safety and stability of food products.