Impact of poly-lactic acid packaging material on semi-hard cheese

A study was performed in order to evaluate the impact of a poly-lactic acid (PLA) package relative to a polyester packaging material on quality of semi-hard cheese during light exposure and storage in the dark and when applying oxygen scavengers to the cheese packages. Migration of volatile compounds from PLA into the cheese was minute and well below any critical levels. Development of secondary lipid oxidation products and loss of riboflavin primarily took place when both oxygen and light were present. As more oxygen was present in the PLA packages than in the reference packages due to a higher oxygen transmission rate of PLA, a higher degree of lipid oxidation was noted in cheeses packaged in PLA. The degree of lipid oxidation was reduced when applying oxygen scavengers but to a lesser extent than when the products were stored in the dark. Riboflavin was degraded to the same extent in the PLA and the reference-packaged cheeses. The results indicate that dark storage/use of non-transparent materials and reduction of the water vapour transmission rate are recommended when using the present PLA for packaging of semi-hard cheeses in order to protect the products against both lipid oxidation and moisture loss. (c) 2005 Elsevier Ltd. All rights reserved.