Evaluation of mutagenicity associated with Escherichia coli inactivation in UV-treated orange juice

MARIA RODR
ıGUEZ, JUAN OTEIZA, LEDA GIANNUZZI, NOEMI ZARITZKY

TOXICOLOGICAL AND ENVIRONMENTAL CHEMISTRY (PRINT)

Taylor & Francis

Año: 2016 vol. 210 p. 1 - 16

0277-2248

UV radiation is an alternative technology for the elimination ofpathogenic micro-organisms in liquid food. The objectives of thiswork were to investigate mutagenesis using the Ames test in : (1)fresh squeezed orange juice submitted to UV radiation dosesrequired to achieve 5 and 10 log10 reductions of different strains ofEscherichia coli serotype O157:H7 at two temperatures, and (2)commercial pasteurized orange juice submitted to thermaltreatment.Two histidine-auxotrophic strains, Salmonella Typhimurium TA98and TA97a, were used in the Ames test with and without metabolicactivation.In commercial pasteurized orange juices, mutagenesis was notobserved with S. Typhimurium TA98 strain with and withoutmetabolic activation, but high mutagenic effect was observed usingTA97a with metabolic activation.UV radiation did not affect the stability of ascorbic acid in aqueoussolution. However, degradation of ascorbic acid was observed whenUV treatment was performed on squeezed orange juice, followingfirst order kinetics.UV treatment required to achieve 5 log10 reductions (1.5 J/cm2) didnot show a mutagenic effect with and without metabolic activationusing the tested strains, but a higher UV radiation dose necessary toproduce 10 log10 reductions (3.0 J/cm2) showed mutagenicity withmetabolic activation.