Hurdle Technology

Only available on StudyMode
  • Download(s) : 140
  • Published : March 6, 2013
Open Document
Text Preview
NOTES ON FOOD PRESERVATION & PACKAGING FOR MSc STUDENTS By Prof C S Purushothaman – Feb 2013

HURDLE TECHNOLOGY
The spoilage and poisoning of foods by micrnorgenisms is a problem that is not yet under adequate control, despite the range of preservation techniques available (e.g. freezing, blanching, pasteurizing and canning). In fact, the current Consumer demand for more natural and fresh-like foods, which urges food manufacturers to use only mild preservation techniques (e.g. refrigeration, modifed-atmosphere packaging and bio-conservation), should make this problem even greater. Thus, for the benefit of food manufacturers there is a strong need for new or improved mild preservation methods that allow for the production and fresh-like, but stable and safe foods. The concept of hurdle technology is not new but addresses this need in full. Hurdle technology (also called combined methods, combined processes, combination preservation, combination techniques or barrier technology) advocates the deliberate combination of existing and novel preservation techniques in order to establish a series of preservative factors (hurdles) that any microorganisms present should not be able to overcome. These hurdles may be temperature, water activity (a,), pH, redox potential, preservatives, and so on. It requites a certain amount of effort from a microfganism to overcome each hurdle. The 'higher" the hurdle, the greater the effort (i.e. the larger the number of orgenisms needed to overeome it). Some hurdles, like pasteurization, can be high for a large number of different types of microorganisms whereas others, like salt content, have a less strong effect or the effect is limited in the range of types of microorganisms it effects. The fact that a combination of preservative factors influences the microbial stability and safety of foods has been known for many centuries. Tbe concept is more or less unconsciously used in many traditional foods, especially in the developing countries. It was re-invented some 15 years ago in the meat industry where the conscious employment of hurdles was found to be highly favonrable for the production of shelf-stable sausages. The concept is now ready to be introduced for use with much wider range of food products, including fruits vegetables, bakery products, dairy products, fish, and so on. Several novel preservative factors (e.g.gas packaging, bioconservation, bacteriocins, ultra high pressure

1

NOTES ON FOOD PRESERVATION & PACKAGING FOR MSc STUDENTS By Prof C S Purushothaman – Feb 2013

treatment, edible coatings, etc. that specifically facilitate this development have been assessed. Hurdle technology is a crucial concept for the mild conservation of foods, as the hurdles in a stable product concertedly control microbial spoilage and food poisontag, leaving desiged fennentation processes unaffected. Because of their concern sometimes synergistic effect. individual hurdles may be set at lower intensities than would be required if only a single hurdle were used as the preservation technique. The application of this concept has proven very successful as an appropriate combination of hurdles achieves microbial stability and safety and also stabilizes the sensory, nutritive and economic properties of a food EXAMPLES OF HURDLE EFFECT A food product is mlcrobiologically stable and safe because of the presence of a set of hurdles that is specific for the product, in terms of the nature and strength of their effect. Together these burdles keep spoilage or pathogenic organisms under control because these microorganisms cannot overcome ('jump over') all of the hurdles present. Exmnples of sets of hurdtes are illustrated in figure below ( a to e).

2

NOTES ON FOOD PRESERVATION & PACKAGING FOR MSc STUDENTS By Prof C S Purushothaman – Feb 2013

The example shown above represents a food containing six hurdles: high temperature during processing (F value), low temperature during storage (t value), low...
tracking img