Detection of irradiated food by the changes in protein molecular mass distribution

Protein constituents were extracted from chicken drumstick and chicken white meat, separated according to the molecular mass (Mm), using discontinuous SDS-polyacrylamide electrophoresis (SDS-PAGE) and quantified by scanning densitometry. The obtained profiles were compared with the profiles corresponding to the meat samples which were irradiated at -20. +4, and +20 degrees c. It was observed that the irradiation of chicken while meat led to protein scission which was partially unselective (e.g. the amount of proteins whose Mm GT 20 kDa decreased, while the amount of those whose Mm LT 20 kDa increased), and partially selective (e.g, the appearance of Mm congruent to 16 kDa fragment). In the case of chicken drumstick meat the irradiation caused both protein scission and protein crosslinking (unselective and selective, and appearance of 16 kDa fragment). However, in the case of aerated dehydrated egg white proteins, irradiation led only to unselective protein scission. The obtained results are discussed in view of possible application of discontinuous analytical SDS-PAGE combined with laser scanning densitometry for detection of previously irradiated foodstuff. (C) 1999 Elsevier Science Ltd. All rights reserved. 9th Tihany Symposium on Radiation Chemistry, Aug 29-Sep 03, 1998, Tatabanya, Hungary