Hurdle technology
Hurdle technology is a method of ensuring that
food products can be eliminated or controlled. This means the food products will be safe for consumption, and their shelf life will be extended. Hurdle technology usually works by combining more than one approach. These approaches can be thought of as "hurdles" the pathogen has to overcome if it is to remain active in the food. The right combination of hurdles can ensure all pathogens are eliminated or rendered harmless in the final product.[1]
Hurdle technology has been defined by Leistner (2000) as an intelligent combination of hurdles which secures the
food products.[2]
The organoleptic quality of the food refers to its sensory properties, that is its look, taste, smell and texture.
Examples of hurdles in a
redox potential, or the presence of preservatives. According to the type of pathogens and how risky they are, the intensity of the hurdles can be adjusted individually to meet consumer preferences in an economical way, without compromising the safety of the product.[1]
Hurdles
Each hurdle aims to eliminate, inactivate or at least inhibit unwanted microorganisms. Common salt or organic acids can be used as hurdles to control microbials in food. Many natural antimicrobials such as nisin, natamycin and other bacteriocins, and essential oils derived from rosemary or thyme, also work well.
| Principal hurdles used for food preservation (after Leistner, 1995)[3][4] | ||
|---|---|---|
| Parameter | Symbol | Application |
| High temperature | F | Heating |
| Low temperature | T | Chilling, freezing |
| Reduced water activity | aw | conserving
|
| Increased acidity
|
pH | Acid addition or formation (pickling) |
| Reduced redox potential
|
Eh | Removal of oxygen or addition of ascorbate
|
Biopreservatives
|
Competitive fermentation
| |
| Other preservatives | ||
"Traditionally,
C. botulinum. Growth of lactic acid bacteria during fermentation results in acid production from metabolism of added sugars and rice. The result is a pH hurdle important in controlling growth of C. botulinum."[1]
| Types of hurdles used for food preservation (from Ohlsson and Bengtsson, 2002)[4][5] | ||
|---|---|---|
| Type of hurdle | Examples | |
| Physical | Aseptic packaging, electromagnetic energy (microwave, radio frequency, pulsed magnetic fields, high electric fields), high temperatures (blanching, pasteurization, sterilization, evaporation, extrusion, baking, frying), ionizing radiation, low temperature (chilling, freezing), modified atmospheres, packaging films (including active packaging, edible coatings), photodynamic inactivation, ultra-high pressures , ultrasonication, ultraviolet radiation
| |
| Physicochemical | Carbon dioxide, ethanol, surface treatment agents
| |
Microbial
|
Antibiotics, bacteriocins, competitive flora, protective cultures | |
Synergistic effects
There can be significant
synergistic effects between hurdles. For example, Gram-positive bacteria include some of the more important spoilage bacteria, such as Clostridium, Bacillus and Listeria. A synergistic enhancement occurs if nisin
is used against these bacteria in combination with antioxidants, organic acids or other antimicrobials. Combining antimicrobial hurdles in an intelligent way means other hurdles can be reduced, yet the resulting food can have superior sensory qualities.
See also
References
- ^ ISBN 978-1-4051-8070-2.
- ^ Leistner I (2000) "Basic aspects of food preservation by hurdle technology" International Journal of Food Microbiology, 55:181–186.
- ISBN 978-0-8342-1341-8.
- ^ a b Lee S (2004) "Microbial Safety of Pickled Fruits and Vegetables and Hurdle Technology" Archived 2011-09-01 at the Wayback Machine Internet Journal of Food Safety, 4: 21–32.
- ISBN 978-1-85573-547-7.
