U.S. Department of Agriculture, Agricultural Research Service, Wyndmoor, PA 19038, USA.
Hawkins Inc., Roseville, MN 55113, USA.
J Food Prot. 2023 Jan;86(1):100019. doi: 10.1016/j.jfp.2022.100019. Epub 2022 Dec 1.
Viability of cells of Listeria monocytogenes or Salmonella spp. was quantified on slices of a German-style bologna manufactured by a local butcher to contain no added antimicrobials or to include 0.9% or 1.3% of a blend of potassium acetate and sodium diacetate (K-Ace) or 2.5% of a blend of potassium lactate and sodium diacetate (K-Lac) as ingredients. After slicing (ca. 7.1 cm L by 6.7 cm W, ca. 0.5 cm thick, ca. 22.4 g each), a single slice of bologna was placed into a nylon-polyethylene bag and surface inoculated with 250 µL per side of a five-strain mixture of either cells of L. monocytogenes or Salmonella spp. to achieve an initial level of ca. 3.5-4.0 log CFU/slice. The packages were vacuum-sealed and then stored at 4 or 12°C for 90 and 30 days, respectively. Without antimicrobials added to the formulation, L. monocytogenes numbers increased by ca. 5.4 and 6.0 log CFU/slice at both 4 and 12°C during the entire 90- and 30-day storage period, respectively. Likewise, levels of Salmonella also increased by ca. 6.0 log CFU/slice at 12°C in the absence of added antimicrobials; however, levels of this pathogen decreased by ca. 1.7 log CFU/slice after 90 days at 4°C. With the inclusion of 0.9% or 1.3% K-Ace or 2.5% K-Lac in the bologna formulation, levels of L. monocytogenes decreased by ca. ≤0.7 log CFU/slice after 90 days at 4°C, whereas levels of Salmonella decreased by ca. 1.6-2.3 log CFU/slice. After 30 days at 12°C, levels of L. monocytogenes increased by ca. ≤3.4 log CFU/slice on product containing 0.9% K-Ace or 2.5% K-Lac but remained relatively unchanged on slices formulated with 1.3% K-Ace. For Salmonella, in the presence of 0.9% or 1.3% K-Ace or 2.5% K-Lac, pathogen levels decreased by ca. ≤0.7 log CFU/slice at 12°C after 30 days. Our data validate that the inclusion of K-Ace (0.9% or 1.3%) or K-Lac (2.5%) as ingredients is effective for controlling L. monocytogenes and Salmonella on slices of bologna during refrigerated storage.
在当地屠夫制作的一种德国式博洛尼亚切片中，李斯特菌或沙门氏菌细胞的存活能力被定量评估。这些切片未添加任何抗菌剂，或包含 0.9%或 1.3%的醋酸钾和双乙酸钠混合物（K-Ace），或 2.5%的乳酸钾和双乙酸钠混合物（K-Lac）作为成分。切片后（约 7.1 厘米长×6.7 厘米宽，约 0.5 厘米厚，每个约 22.4 克），将一片博洛尼亚放入尼龙-聚乙烯袋中，每侧用 250µL 的五株李斯特菌或沙门氏菌混合物进行表面接种，以达到约 3.5-4.0 log CFU/切片的初始水平。包装采用真空密封，然后分别在 4°C或 12°C下储存 90 天和 30 天。在没有添加抗菌剂的配方中，李斯特菌数量在整个 90 天和 30 天的储存期内，在 4°C 和 12°C 下分别增加了约 5.4 和 6.0 log CFU/切片。同样，在没有添加抗菌剂的情况下，沙门氏菌的水平在 12°C 下也增加了约 6.0 log CFU/切片；然而，在 4°C 下 90 天后，这种病原体的水平下降了约 1.7 log CFU/切片。在博洛尼亚配方中添加 0.9%或 1.3%的 K-Ace 或 2.5%的 K-Lac 后，李斯特菌的水平在 4°C 下 90 天后下降了约≤0.7 log CFU/切片，而沙门氏菌的水平下降了约 1.6-2.3 log CFU/切片。在 12°C 下储存 30 天后，在含有 0.9% K-Ace 或 2.5% K-Lac 的产品上，李斯特菌的水平增加了约≤3.4 log CFU/切片，但在含有 1.3% K-Ace 的切片上，李斯特菌的水平相对不变。对于沙门氏菌，在 0.9%或 1.3%的 K-Ace 或 2.5%的 K-Lac 存在的情况下，在 30 天的冷藏储存后，病原菌水平下降了约≤0.7 log CFU/切片。我们的数据验证了在冷藏储存期间，在博洛尼亚切片中添加 K-Ace（0.9%或 1.3%）或 K-Lac（2.5%）作为成分可有效控制李斯特菌和沙门氏菌。
