Applications of Bacteriocins in Food Systems

Abstract

Renewed interest in the use of bactericidal proteins (bacteriocins) as food protection and preservation agents is due in part to new food safety challenges, the affirmation of the bacteriocin Nisin as a GRAS additive in certain foods, the potential of using molecular biology to manipulate bacteriocin production, and a growing interest in so-called “natural” food preservatives. Bacteriocins may be introduced into foods by different mechanisms: 1) In lactic fermented foods the bacteriocins may be present as a result of the growth of bacteriocinogenic lactic acid bacteria. 2) Bacteriocins may be introduced as a constitutent of lactic food fermentation by-products (such as whey) into other foods. 3) Bacteriocins may be purified, concentrated and added directly as an additive. The activity of bacteriocins in foods will be highly dependent on physical and chemical factors such as pH, ionic strength, solubility and temperature. Bacteriocins as proteins may also be susceptible to enzymatic degradation and non-specific binding. The narrow spectrum of activity of certain bacteriocins is also a limiting factor in food applications. An effective bacteriocin for use as a food preservative should meet minimum requirements such as: 1) Non-toxic. 2) Stable and highly active. 3) Possessing a broad spectrum of activity. 4) No effect on sensory attributes of food. 5) Inexpensive and simple to use. The bacteriocin Nisin has shown the most promise as an effective food preservative, however, other bacteriocins produced by lactic acid bacteria are now being investigated for potential application in foods.