Inactivation of Alicyclobacillus acidoterrestris spores in apple and orange juice concentrates by gamma irradiation.
The objective of this study was to evaluate the effect of different concentrations of reconstituted apple and orange juice on reduction of Alicyclobacillus acidoterrestris spores by gamma irradiation. Spores of A. acidoterrestris were inoculated into three concentrations of apple (18, 36, and 72 °Brix) and orange (11, 33, and 66 °Brix) juice and subjected to five radiation doses (1, 3, 5, 7, and 10 kGy). No significant reductions (P > 0.05) in spores were observed after the 1-kGy treatment for all apple and orange concentrations. Spores in 18, 36, and 72 °Brix apple juice concentrates subjected to 10 kGy were reduced to 4.34, 3.9, and 3.84 log CFU/ml, respectively. Similar results were observed for orange juice. When 10 kGy was applied to 11 °Brix orange juice, populations of spores were reduced by 5 log CFU/ml. The reduction of spores in 33 and 66 °Brix orange juice concentrates exposed to 10-kGy gamma irradiation was 4.54 and 3.85 log CFU/ml, respectively. Juice concentration did not affect (P > 0.05) the number of surviving A. acidoterrestris spores from the same kGy treatment. Gamma irradiation treatment did not change the pH or water activity of the juice (P > 0.05).
Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea 4928.
Su-Yeon
SY
Lee
Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea 4928.
Sang-Hyun
SH
Park
Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea 4928. kang7820@snu.ac.kr.
Dong-Hyun
DH
Kang
D056450:Alicyclobacillus / Q000528:radiation effects*; D001628:Beverages / Q000382:microbiology*; D032084:Citrus sinensis / Q000382:microbiology; D015169:Colony Count, Microbial; D004307:Dose-Response Relationship, Radiation; D005506:Food Contamination / Q000032:analysis* / Q000517:prevention & control; D005514:Food Irradiation / Q000379:methods*; D005720:Gamma Rays; D006358:Hot Temperature; D006801:Humans; D027845:Malus / Q000382:microbiology; D013171:Spores, Bacterial / Q000528:radiation effects*