Fundamental Food Microbiology, Third Edition - Fuad Fathir

500 FUNDAMENTAL FOOD MICROBIOLOGY
The regulatory requirements include the expected effectiveness of an antimicrobial
agent in a food system. It should be effective in small concentrations and should
not hide any fault of a food (e.g., conceal poor quality and spoilage). Most importantly,
it should be safe for human consumption. Finally, when required, it should
be listed in the label, indicating its purpose in the food.
IV. EXAMPLES OF ANTIMICROBIAL PRESERVATIVES
Foods can have antimicrobial compounds in three ways: present naturally, formed
during processing, or added as ingredients. Those added have to be GRAS-listed
and approved by regulatory agencies. Some of these are added specifically as antimicrobial
preservatives, whereas others, although having antimicrobial properties,
are added for different reasons. Those in the latter group are also called indirect
antimicrobials. In this chapter, the antimicrobial effectiveness, mode of action, and
uses in foods of some inorganic and organic antimicrobials added to foods are briefly
discussed. 1–7 Table 37.1 lists some antimicrobial preservatives (direct or indirect)
used in foods. 1–6
A. Nitrite (NaNO 2 and KNO 2)
Curing agents that contain nitrite, and together with NaCl, sugar, spices, ascorbate,
and erythorbate, are permitted for use in heat-processed meat, poultry, and fish
products to control growth and toxin production by Clostridium botulinum. Nitrate
and nitrite are also used in several European countries in some cheeses to prevent
gas blowing by Clo. butyricum and Clo. tyrobutyricum. The mechanisms of antibacterial
action of nitrite are not properly understood, but the inhibitory effect is
probably produced in several ways, such as reactions with some enzymes in vegetative
cells and germinating spores, restriction of the bacterial use of iron, and
interference with membrane permeability, thereby limiting transport. In addition to
clostridial species, nitrite is inhibitory, to some extent, to Staphylococcus aureus,
Table 37.1 Some Antimicrobial Chemical Preservativesa Used in Foods
Acetaldehyde Dehydroacetate Lactic acid Propylene glycol
Acetic acid Diacetate Lauric acid Propylene oxide
Ascorbic acid Diacetyl Lysozyme Propyl gallate
Bacteriocins Diethyl dicarbonate Malic acid Smoke
Benomyl Diphenyl Methyl bromide Sodium chloride
Benzoic acid Ethyl alcohol Monolaurin Sorbic acid
Betapropiolactum Ethyl formate Natamycin Spices
BHA, BHT, and TBHQ EDTA Nitrite and nitrate Succinic acid
Boric acid Ethylene oxide Parabens Sucrose
Caprylic acid H2O2 Peracetate Sulfites and SO2 Chitosan Polyphosphates Tetracyclines
Citric acid Propionic acid Thiabendazole
CO2 and CO Tylosin
a Not all are permitted in the U. S.