The project concerned: developing safe commercial applications of novel high oxygen, argon and nitrous oxide modified atmosphere packaging (MAP) for extending the high quality shelf-life of a wide range of prepared fruit and vegetables; investigating the synergy between non-sulphite dips and novel MAP for inhibiting the discolouration of prepared produce; investigating the microbial and biochemical spoilage mechanisms which are inhibited by novel MAP; assessment of the effects of high oxygen MAP on various easily-lost nutrients.
Recent findings are as follows. The compatibility issue of MAP machinery with high oxygen levels has been successfully addressed and a guidelines document prepared on the safe use of high oxygen MAP. Many non-sulphite chemical and biological agents have been screened and several were effective at inhibiting enzymic discolouration of prepared potatoes. Evidence has been gathered of a synergistic effect between high oxygen MAP and non-sulphite dipping for discolouration inhibition of prepared potatoes. High oxygen MAP has beneficial effects on sensory quality in comparison with conventional low oxygen MAP for many prepared produce items. High oxygen MAP inhibits certain generic groups of microorganisms and a variety of specific food pathogenic and spoilage microorganisms. This is due to the combination of high oxygen and generated carbon dioxide, rather than the individual gases. Initial results have shown that nitrous oxide is capable of inhibiting certain microorganisms. Respiration rates of selected prepared produce items were not significantly affected by high oxygen or high argon levels, but were reduced in combination with carbon dioxide. Beneficial effects of high oxygen and high argon MAP were found on the retention of ascorbic acid, on indicators of lipid oxidation, and on inhibition of enzymic browning in cut lettuce. Analytical procedures for measuring individual antioxidants and total antioxidant capacity of selected prepared produce items have been successfully developed.