A coating for use as an antimicrobial and antioxidative packaging material incorporating nisin and α-tocopherol

A 3-mm thick nisin and/or alpha-tocopherol coating at a concentration of 3% was applied on a paper using a binder medium of vinyl acetate-ethylene copolymer to confer an antimicrobial and antioxidative property for use in the food packaging industry. The migration of nisin and alpha-tocopherol from the coating to a model emulsion composed of 66% water and 32% paraffin oil with 2% emulsifier was measured, and this was linked to the suppression of microbial growth and oxidative deterioration in the emulsion and in milk cream at 10 degreesC. The nisin migrated more slowly than alpha-tocopherol, and reached 9.3% of the total concentration incorporated in the coating, with alpha-tocopherol reaching an equilibrium level of 5.7%. The migration of each of the additives was not affected by the presence of the other. Incorporation of nisin in the coating was effective in inhibiting Micrococcus flavus, and alpha-tocopherol incorporation retarded lipid oxidation in the model emulsion and in the milk cream. Thus, the combination of nisin and alpha-tocopherol in the coating conferred both antimicrobial and antioxidative properties. However, it did not provide any further synergistic antimicrobial and antioxidative effect when compared to a single additive alone. (C) 2003 Elsevier Ltd. All rights reserved.