Fate of salmonellae in orange and grapefruit concentrates during cold storage.
Orange and grapefruit concentrates at 42, 50, and 64 degreesBrix were inoculated with a five-strain cocktail of acid-adapted salmonellae stored at 0, -5, -10, -15, or -20 degrees C and sampled for population survival up to 11 and 50 days for grapefruit and orange concentrates, respectively. Survivor curves were nonlinear and best fit by a three-parameter power equation: Y = a + bXc. Final log reductions ranged from 2.3 to 4.8 after 50 days in orange concentrate and 6.0 to 6.9 after 11 days in grapefruit concentrate. Storage times needed to achieve a 5-log population reduction among all treatments for grapefruit concentrate ranged from 1.0 to 5.8 days. Significant differences (P < or = 0.05) were observed among results for different temperatures within any single Brix level; however, storage times among Brix levels at any one temperature were not significantly (P < or = 0.05) different. Results indicate that cold storage of grapefruit concentrate is a viable treatment for achieving a 5-log reduction in salmonellae.
Parish
Mickey E
ME
Food Science and Human Nutrition, University of Florida, IFAS, Citrus Research and Education Center, Lake Alfred, Florida 33850, USA. MEParish@crec.ifas.ufl.edu
Goodrich
Renée
R
Miller
William
W
D001628:Beverages / Q000382:microbiology*; D032083:Citrus paradisi; D032084:Citrus sinensis; D003080:Cold Temperature; D015169:Colony Count, Microbial; D005506:Food Contamination / Q000032:analysis; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012475:Salmonella / Q000254:growth & development*; D013997:Time Factors