Anellis A, Berkowitz D, Jarboe C, el-Bisi H M
Appl Microbiol. 1969 Oct;18(4):604-11. doi: 10.1128/am.18.4.604-611.1969.
Ten lots of pork loin, packed in cans, were inoculated with approximately 10(6)Clostridium botulinum spores per can. Each lot was seeded with a different strain; five type A and five type B strains were used. The pack comprised 5,690 cans, including controls, and contained about 10(9) spores per dose. The cans were irradiated with Co(60) in the range of 0 to 5.0 Mrad (0.5 Mrad increments) at 5 to 25 C, incubated for 6 months at 30 C, and examined for swelling, toxicity, and recoverable C. botulinum. The minimal experimental sterilizing dose (ESD) based on nonswollen, nontoxic, but nonsterile end points was 2.5 < ESD </= 3.0 Mrad, and based on non-spoiled sterile cans was 3.5 < ESD </= 4.0 Mrad. The theoretical minimal radiation dose (MRD), the 12D equivalent, varied with the method of computation: 4.74, 4.33 +/- 0.17, and 4.19 to 4.99 Mrad were obtained by the Weibull, Spearman-Karber, and Schmidt-Nank techniques, respectively. Calculation of D and MRD values by the conventional Schmidt-Nank method produced increasing values with rising dosage; this finding was compared with the data derived by the other two methods of calculation. Suggestions for estimating the MRD of a prototype radiation process are offered.
十罐罐装猪里脊肉，每罐接种约10⁶个肉毒梭菌孢子。每罐接种不同菌株；使用了五株A型菌株和五株B型菌株。包装包括5690罐，其中有对照罐，每剂量约含10⁹个孢子。这些罐头在5至25℃下用钴⁶⁰进行0至5.0兆拉德（以0.5兆拉德递增）的辐照，在30℃下培养6个月，然后检查是否膨胀、是否有毒以及能否检测到可复苏的肉毒梭菌。基于无膨胀、无毒但未无菌的终点确定的最小实验灭菌剂量（ESD）为2.5＜ESD≤3.0兆拉德，基于未变质无菌罐头确定的最小实验灭菌剂量为3.5＜ESD≤4.0兆拉德。理论最小辐射剂量（MRD），即12D当量，随计算方法而异：通过威布尔法、斯皮尔曼 - 卡尔伯法和施密特 - 南克法分别得到4.74、4.33±0.17和4.19至4.99兆拉德。用传统的施密特 - 南克法计算D值和MRD值时，其值随剂量增加而增大；将这一结果与通过其他两种计算方法得出的数据进行了比较。文中还给出了估算原型辐照工艺MRD的建议。
