Effect of ionic strength on inactivation kinetics of Escherichia coli O157：H7 by electron beam in ground beef,chicken breast meat, and trout fillets英文电子书.pdf

894 International Journal of Food Science and Technology 2007, 42, 894–902 Original article Effect of ionic strength on inactivation kinetics of Escherichia coli O157:H7 by electron beam in ground beef, chicken breast meat, and trout fillets Jennifer Lea Black Jacek Jaczynski* West Virginia University, Division of Animal and Veterinary Sciences, PO Box 6108, Morgantown, WV 26508, USA (Received 21 March 2006; Accepted in revised form 25 April 2006) Summary The ionic strengths (IS) of ground beef, chicken meat, and trout fillets were modified to intermediate and highest with 3.5% and 7.0% NaCl, respectively. The samples with modified and unaltered (native) IS were inoculated with Escherichia coli O157:H7 and subjected to electron beam (e-beam). The water activity (aw) of the meat samples were 1.0, 0.96–0.97, and 0.94 for native, intermediate, and highest IS. The D10-values were calculated from survivor curves. The D10-values for E. coli ranged from 0.19 kGy in trout (highest IS) to 0.31 kGy in beef and chicken (highest IS). Regardless of the meat type, the increased resistance of E. coli to e-beam was only observed at the highest IS. The difference of the D10-value for E. coli in samples at intermediate and native IS was insignificant. Regardless of the IS, the E. coli in trout was most sensitive, while the difference of E. coli resistance to e-beam in ground beef and chicken meat was insignificant. Keywords D-value, electron beam, Escherichia coli O157:H7, inactivation kinetics, ionic strength, non-thermal food preservation.