application of alternative food-preservation - Bentham Science
application of alternative food-preservation - Bentham Science
application of alternative food-preservation - Bentham Science
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Application <strong>of</strong> Alternative Food-Preservation Technologies to Enhance Food Safety & Stability, 2010, 83-91 83<br />
Antimicrobial Agents <strong>of</strong> Microbial Origin : Nisin<br />
Daniela D’Amato* and Milena Sinigaglia<br />
Department <strong>of</strong> Food <strong>Science</strong>, Faculty <strong>of</strong> Agricultural <strong>Science</strong>, University <strong>of</strong> Foggia, Italy<br />
Antonio Bevilacqua, Maria Rosaria Corbo and Milena Sinigaglia (Eds)<br />
All rights reserved - © 2010 <strong>Bentham</strong> <strong>Science</strong> Publishers Ltd.<br />
CHAPTER 6<br />
Abstract: Nisin belongs to a group <strong>of</strong> bacteriocins known as “lantibiotics”, small peptides produced by<br />
Gram-positive bacteria <strong>of</strong> different genera. Nisin consists <strong>of</strong> 34 amino acids and is the only commercially<br />
accepted bacteriocin for <strong>food</strong> <strong>preservation</strong>; it is produced by certain strains <strong>of</strong> Lactococcus lactis subsp.<br />
lactis. Nisin is a natural, toxicologically safe, antibacterial <strong>food</strong> preservative, characterized by an<br />
antimicrobial activity against a wide range <strong>of</strong> Gram-positive bacteria, but not against Gram-negative bacteria,<br />
yeasts or fungi. It can act against Gram-negative bacteria, in conjunction with chemically induced damage <strong>of</strong><br />
the outer membrane. Nisin was labeled as GRAS (generally recognized as safe) in 1988 by FDA, and is<br />
currently permitted as a <strong>food</strong> additive in over 50 countries around the world.<br />
Nisin has found practical <strong>application</strong> as a natural <strong>food</strong> preservative in many categories <strong>of</strong> <strong>food</strong>, such as<br />
natural cheese (Emmental and Gouda), processed cheese (slices, spread, sauces and dips), pasteurized dairy<br />
products (milk, chilled desserts, clotted cream and mascarpone cheese), egg products, hot baked flour<br />
products (crupets), canned products, alcoholic beverages (beer and wine), salad dressing, meat and fish<br />
products, yogurt and pasteurized soups.<br />
Key-concepts: Mode <strong>of</strong> action, Safety, Food <strong>application</strong>s.<br />
INTRODUCTION<br />
Bacteria are a source <strong>of</strong> antimicrobial peptides, which have been examined for <strong>application</strong>s in microbial <strong>food</strong><br />
safety. The antimicrobial proteins or peptides produced by bacteria are termed bacteriocins. They are<br />
ribosomally synthesized and kill closely related bacteria [1]. Many bacteriocins have a narrow host range, and<br />
are likely most effective against related bacteria competing for the same scarce resources. Although bacteriocins<br />
are produced by many Gram positive and Gram negative species, those produced by the Lactic Acid Bacteria<br />
(LAB) are <strong>of</strong> particular interest to the <strong>food</strong> industry, since these bacteria have generally been regarded as safe<br />
(GRAS status) [2].<br />
Bacteriocins are used as a preservative in <strong>food</strong> due to its heat stability, wider pH tolerance and its proteolytic<br />
activity [3]. Bacteriocins have <strong>application</strong>s in hurdle technology, which utilizes synergies <strong>of</strong> combined<br />
treatments to preserve <strong>food</strong> more effectively.<br />
Bacteriocins have been grouped into four main distinct classes [4].<br />
Class-I Lantibiotics characterized by the presence <strong>of</strong> unusual thioether amino acid which are<br />
generated through post translational modification.<br />
Class-II Bacteriocins represent small (30 kD) heat labile protein.<br />
Class-IV Represent complex bacteriocins that contain essential lipid, carbohydrate moieties in<br />
addition to a protein compared.<br />
NISIN: STRUCTURE AND PROPERTIES<br />
Nisin is the best known and widely used bacteriocin, employed as a <strong>food</strong> preservative, with a high antibacterial<br />
activity and a relatively low toxicity for humans. It is <strong>of</strong>ten used in various <strong>food</strong> system including dairy, meat<br />
*Address correspondence to this author Daniela D'Amato at: Department <strong>of</strong> Food <strong>Science</strong>, Faculty <strong>of</strong> Agricultural <strong>Science</strong>, University <strong>of</strong><br />
Foggia, Italy; E-mail: d.damato@unifg.it