THE TBA METHOD AS AN INDEX OF OXIDATION OF THERMALLY PRESERVED TURKEYMEAT IN PLASTIC TRAYS AND CANS

Thiobarbituric acid (TBA) determinations of malondialdehyde (MDA) in t hermally preserved red turkey meat packed in high barrier plastic tray s and in cans, were carried out as a function of product layer and sto rage temperature (15, 25 and 35C). Several types of plastic trays, wit h different oxygen permeabilities, were evaluated. In the most permeab le plastic trays the product in the surface layer reached maximum TBA values at all storage temperatures after a certain storage period, fol lowed by their decrease. In the higher barrier trays and in the cans, the TBA values decreased continuously with time. The peak TBA values, observed in the least barrier plastic trays declined with storage temp erature. In the inner product layers, the TBA values decreased during storage in all types of packages and at all temperatures. The reductio n in TBA values can be explained by the disappearance of TBA reacting substances (TBARS). The extent of TBARS disappearance was greater in t he absence of oxygen than in its presence. The results of this study i ndicate that TBA determinations are not a reliable indicator for quali ty deterioration during storage of thermally treated meat products in plastic packages.