Modified packaging as protection against photodegradation of the colour of pasteurized, sliced ham.

Carbon dioxide flushing and packaging under slight overpressure has been found to eliminate discoloration of vacuum-packed ham, normally encountered as a result of photooxidation of nitric oxide pigments during the first 24 h of display in illuminated cabinets. On exposure to light, even when the product is packed in high-vacuum, residual oxygen invariably present in the product gives rise to significant photochemical pigment degradation and general poor oxidative stability, and has warranted up to 4 days of dark storage prior to display. Replacement of the atmosphere with carbon dioxide, even when repeated, followed by the establishment of vacuum, does not yield a similar protection.