Chemical Preservation


  • When hygienic principles were little practical, and less understood, chemical preservatives were not infrequently used in food to offset what is now recognized as micro biologically dangerous action.
  • Nevertheless, this remedy has drawbacks because chemical preservative may be non-specific protoplasmic poison and as undesirable for the consumer as for the microorganism against which they are directed; moreover their effect may be cumulative rather than immediate.
  • Preservative means any substance, which is capable of inhibiting, retarding or arresting the process of fermentation, acidification or other deterioration of food or of masking any of the evidence putrefaction but does not include common salt, lecithins, sugars or tocopherols; nicotinic acid or its amide, vinegar or acetic acid, lactic acid, ascorbic acid, citric acid, malic acid, phosphoric acid, pyrophosphoric acid or tartaric acid or the calcium, sodium or potassium saltsof them, glycerol, alcohol, or portable spirits, isopropyl alcohol, propylene glycol, monoacetin, diacetin, or triacetin, herbs, spices or their extracts, or essential oils when used for the purposes of flavouring.
  • There are many chemicals, which prevent microbial growth in foods and act as preservatives. Several organic acids have been Generally Recognized As Safe (GRAS) for use as chemical preservatives.
  • More recently, however, the addition of nicotinamide and ascorbic acid to meat, as colour preservative, was prohibited.
  • Formaldehyde, as such, is also prohibited, since it is demonstrably toxin, but is permitted up to 5ppm.
  • Fresh meat, when in the intact carcass, is not usually severely contaminated.
  • On the other, in preparing products containing comminuted or minced meats, there is every possibility for massive bacterial contamination from the hands of operatives or from equipment.
  • Hence, chemical preservatives were particularly employed in relation to meat.
  • Very few chemicals are now permitted as preservatives and these only in minute quantities.
  • Apart from nitrate, nitrite, sorbic, acid and tetracyclines, the U.K. preservatives in food regulations act , 1962 lists only seven, namely sulphur-di-oxide, propionic acid, benzoic acid, methyl-p-hydroxy-benzoate, ethyl-p-hydroxy-benzoate, diphenyl, O-phenylphenol and copper carbonate, of these seven, only sulphur di-oxide is permitted in meat preservation up to 450 ppm being in sausage and sausage meat.
  • Its effect is antimicrobial, and at that permitted level it has no beneficial effect on meat colour, so that deception of the public on this basis not possible.
  • Boric acid was also employed until relatively recently both in sausage meat and in curing; but its use in the U.K. was discontinued in the afore mentioned Act of 1928.
  • Spices and essential oils are excluded from the U.K. preservatives in food regulations act , when used for flavoring purpose as per regulations.
  • Various essential oils have preservation properties and have been used to extend the storage life of meat products.
  • These include eugenol in cloves and alkyl isothiocyanate in mustard seed and 0.3 percent of sage or rosemary was inhibitory and 0.5 percent bactericidal.
  • Carbon-di-oxide and ozone have been used to discourage the growth of surface microorganisms on beef carcasses during prolonged storage at chill temperatures.
  • Since, ozone leavesĀ  toxic residues in the meat, its use in the store can be dangerous for personnel and it accelerates the oxidation of fat and is more effective against air-borne microorganisms than against those on the meat.
  • Citric acid, propionic acid, benzoic acid and their salts are effective mould inhibitors.
  • Acetic acid and lactic acid prevent bacterial growth.
  • Sorbate and benzoate are capable of arresting the growth of yeast in foods.
Last modified: Tuesday, 10 April 2012, 11:04 AM