Conditionally permitted antioxidants

Table 12.6 Antioxidants which are conditionally permitted in foods...

Annex III, Conditionally Permitted Preservatives and Antioxidants, is divided as follows with details of the maximinn permitted level of preservative(s) in the appropriate foodstuff ... 

Decomposition of Peroxides by Various Stabilizers. The efficiency of tert-butyl hydroperoxide decomposition in tert-butyl alcohol by various additives was determined (Table 9). Under the conditions of these experiments, the phenolic antioxidants and dilauryl thiodipropionate had little or, often, no effect on the hydroperoxide decomposition. The three zinc salts effectively inhibited peroxide decomposition. This effect might briefly inhibit the onset of substrate oxidation under weathering-test conditions, but the peroxide would decompose whenever its concentration reached a sufficient level to permit significant light... 

Annex III lays down the conditions of use for permitted preservatives and antioxidants, with lists of foods and maximum levels in each case. Part A lists the sorbates, benzoates and p-hydroxybenzoates, E 200-E 219 part B lists sulphur dioxide and the sulphites, E 220-E 228 part C lists other preservatives with their uses, including nisin, dimethyl dicarbonate and substances allowed for surface treatment of certain fruits, E 249 potassium nitrite, E 250 sodium nitrite, E 251 sodium nitrate and E 252 potassium nitrate, E 280-E 283 propionic acid and the propionates part D lists the antioxidants E 320 butylated hydroxyanisole (BHA), E 321 butylated hydroxytoluene (BHT), E 310 propyl gallate, E 311 octyl gallate, E 312 dodecyl gallate, E 315 eiythorbic acid and E 316 sodium erythorbate. 

Only antioxidants which satisfy the requirements laid down by the Scientific Committee for Food may be used in foodstuffs. Having regard to the most recent scientific and toxicological information on these substances, some of them are to be permitted only for certain foodstuffs and under certain conditions of use. On the other hand, a wide range of natural antioxidants may be added to all foodstuffs, with the exception of formulae for special purposes (such as for infants), following the quantum satis principle. 

Antioxidants that may be used in foods that are subject to a standard of identity are laid down in the relevant standard (Table 12.9). In the case of food that is not subject to a standard of identity, additives must be used in accordance with the conditions or limits of use specified in regulations.9 For some types of foodstuffs which have standards of identity, the use of antioxidants is not permitted. No antioxidants may be used, for instance, in dairy products, ices, and egg products. 

White oils, containing no significant levels of aromatics or sulfur-containing compounds, have no antioxidant capability and will undergo oxidation to peroxides and hydroperoxides readily and at the same time show no visible signs of chemical change. Therefore storage conditions should be maintained at ambient temperatures. Because of this instability, addition of an antioxidant such as butylated hydroxytoluene (BHT) or vitamin E is permitted in some jurisdictions. 

As PVC film is no longer permitted to be used as stretch wrap film for food packaging since 2006, PE film is widely used now from supermarket to home in China. BHT, Irganox 1076, and Irgafos 168 are typical antioxidants usually added in several plastic packaging materials especially in PE films. Migration of additives from PP, PET, P VDC, PVC, and PE under traditional conditions is studied in the last a few years but less under microwave heating conditions. 

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