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

Abstract

A 3-mm thick nisin and/or α-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 α-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 °C. The nisin migrated more slowly than α-tocopherol, and reached 9.3% of the total concentration incorporated in the coating, with α-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 α-tocopherol incorporation retarded lipid oxidation in the model emulsion and in the milk cream. Thus, the combination of nisin and α-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.