Hurdle technology is a method of ensuring that pathogens in 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. Hurdle technology has been defined by Leistner (2000) as an intelligent combination of hurdles which secures the microbial safety and stability as well as the organoleptic and nutritional quality and the economic viability of food products.Leistner I (2000
"Basic aspects of food preservation by hurdle technology"
''International Journal of Food Microbiology'', 55:181–186. The organoleptic quality of the food refers to its sensory properties, that is its look, taste, smell and texture. Examples of hurdles in a food system are high temperature during processing, low temperature during storage, increasing the acidity, lowering the water activity or 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.Alasalvar C (2010
''Seafood Quality, Safety and Health Applications''
John Wiley and Sons, Page 203. .

Hurdles

Each hurdle aims to eliminate, inactivate or at least inhibit unwanted microorganisms. Common salt or

organic acid An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids, whose acidity is associated with their carboxyl group –COOH. Sulfonic acids, containing the group –SO2OH, are rel ...

s can be used as hurdles to control microbials in food. Many natural antimicrobials such as

nisin Nisin is a polycyclic antibacterial peptide produced by the bacterium ''Lactococcus lactis'' that is used as a food preservative. It has 34 amino acid residues, including the uncommon amino acids lanthionine (Lan), methyllanthionine (MeLan), dide ...

natamycin Natamycin, also known as pimaricin, is an antifungal medication used to treat fungal infections around the eye. This includes infections of the eyelids, conjunctiva, and cornea. It is used as eyedrops. Natamycin is also used in the food industr ...

and other

bacteriocin Bacteriocins are proteinaceous or peptidic toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strain(s). They are similar to yeast and paramecium killing factors, and are structurally, functionally, and ec ...

s, and essential oils derived from rosemary or thyme, also work well. "Traditionally,

fermented Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes. In biochemistry, it is narrowly defined as the extraction of energy from carbohydrates in the absence of oxygen. In food ...

seafood products common in Japan, provide a typical example of hurdle technology. Fermentation of

sushi is a Japanese cuisine, Japanese dish of prepared , usually with some sugar and salt, accompanied by a variety of , such as seafood, often raw, and vegetables. Styles of sushi and its presentation vary widely, but the one key ingredient is " ...

employs hurdles that favour growth of desirable bacteria but inhibit the growth of pathogens. The important hurdles in the early stages of fermentation are salt and vinegar. Raw fish is cured in salt (20–30%, w/w) for one month before being desalted and pickled in vinegar. The main target of these hurdles is ''

C. botulinum ''Clostridium botulinum'' is a Gram-positive, rod-shaped, anaerobic, spore-forming, motile bacterium with the ability to produce the neurotoxin botulinum. The botulinum toxin can cause botulism, a severe flaccid paralytic disease in humans a ...

''. Growth of

lactic acid bacteria Lactobacillales are an order of gram-positive, low-GC, acid-tolerant, generally nonsporulating, nonrespiring, either rod-shaped (bacilli) or spherical (cocci) bacteria that share common metabolic and physiological characteristics. These bacte ...

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''."

Synergistic effects

There can be significant

synergistic Synergy is an interaction or cooperation giving rise to a whole that is greater than the simple sum of its parts. The term ''synergy'' comes from the Attic Greek word συνεργία ' from ', , meaning "working together". History In Christi ...

effects between hurdles. For example,

Gram-positive bacteria In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bact ...

include some of the more important spoilage bacteria, such as ''

Clostridium ''Clostridium'' is a genus of anaerobic, Gram-positive bacteria. Species of ''Clostridium'' inhabit soils and the intestinal tract of animals, including humans. This genus includes several significant human pathogens, including the causative ag ...

'', ''

Bacillus ''Bacillus'' (Latin "stick") is a genus of Gram-positive, rod-shaped bacteria, a member of the phylum ''Bacillota'', with 266 named species. The term is also used to describe the shape (rod) of other so-shaped bacteria; and the plural ''Bacilli ...

'' and ''

Listeria ''Listeria'' is a genus of bacteria that acts as an intracellular parasite in mammals. Until 1992, 17 species were known, each containing two subspecies. By 2020, 21 species had been identified. The genus is named in honour of the British pi ...

''. A synergistic enhancement occurs if

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.

References

{{food preservation Food preservation

Hurdles

Synergistic effects

See also

References