title: Inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium in black pepper and red pepper by gamma irradiation.
abstract: This study evaluated the efficacy of gamma irradiation to inactivate foodborne pathogens in black pepper (Piper nigrum) and red pepper (dried Capsicum annuum). Black pepper and red pepper inoculated with Escherichia coli O157:H7 and Salmonella Typhimurium were subjected to gamma irradiation in the range of 0, 1, 2, 3 and 5 kGy, and color change was evaluated after treatment. Pathogen populations decreased with increasing treatment doses. A gamma irradiation dose of 5 kGy decreased E. coli O157:H7 and S. Typhimurium populations >4.4 to >5.2 log CFU/g in black pepper without causing color change. Similarly, 5 kGy of gamma irradiation yielded reduction of 3.8 to >5.2 log CFU/g for E. coli O157:H7 and S. Typhimurium in red pepper. During gamma irradiation treatment, L*, a* and b* values of red pepper were not significantly changed except for 297 μm to 420 μm size red pepper treated with 5 kGy of gamma irradiation. Based on the D-value of pathogens in black pepper and red pepper, S. Typhimurium showed more resistant to gamma irradiation than did E. coli O157:H7. These results show that gamma irradiation has potential as a non-thermal process for inactivating foodborne pathogens in spices with minimal color changes.
authors.affiliation: 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, Republic of Korea.
authors.forename: Won-Jae
authors.initials: WJ
authors.lastname: Song
authors.affiliation: 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, Republic of Korea.
authors.forename: Hye-Jung
authors.initials: HJ
authors.lastname: Sung
authors.affiliation: 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, Republic of Korea.
authors.forename: Sung-Youn
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Food Science and Technology, College of Agriculture and Life Sciences, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Kwang-Pyo
authors.initials: KP
authors.lastname: Kim
authors.affiliation: 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, Republic of Korea.
authors.forename: Sangryeol
authors.initials: S
authors.lastname: Ryu
authors.affiliation: 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, Republic of Korea. Electronic address: kang7820@snu.ac.kr.
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Kang
mesh_terms: D002212:Capsicum / Q000382:microbiology*; D015169:Colony Count, Microbial; D019453:Escherichia coli O157 / Q000528:radiation effects*; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D050296:Microbial Viability; D029222:Piper nigrum / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000528:radiation effects*; D017365:Spices / Q000382:microbiology
keywords: Black pepper; Foodborne pathogen; Gamma irradiation; Inactivation; Red pepper