El-Shenawy Moustafa A, Marth Elmer H
Department of Food Science and The Food Research Institute, University of Wisconsin-Madison, Madison, Wisconsin 53706.
J Food Prot. 1988 Nov;51(11):842-847. doi: 10.4315/0362-028X-51.11.842.
Inhibition and inactivation of Listeria monocytogenes by sorbic acid were studied using tryptose broth supplemented with 0, 0.05, 0.1, 0.15, 0.2, 0.25 or 0.3% potassium sorbate; adjusted to pH 5.6 or 5.0; and incubated at 4, 13, 21 or 35°C. The bacterium grew in sorbate-free controls under all conditions except at 4°C and pH 5.0. At pH 5.6 and 4°C, the bacterium was inactivated by 0.25 or 0.3% of potassium sorbate after 66 and 60 d. Other concentrations permitted slight growth followed by decreases in populations. At 4°C and pH 5.0, concentrations of 0.15 to 0.3% potassium sorbate completely inactivated the pathogen in 60 to 36 d, whereas the other concentrations caused a gradual decrease in populations during the incubation period. At 13°C and pH 5.6, L. monocytogenes grew at all test concentrations of potassium sorbate, but the maximum populations were directly related to the concentration of potassium sorbate added to the medium - the higher the concentration, the lower the ultimate maximum population. At 13°C and pH 5.0, concentrations of 0.2, 0.25 or 0.3% potassium sorbate completely inhibited growth and caused complete inactivation of the pathogen, whereas presence of 0.15% or less potassium sorbate allowed growth of the pathogen. At 21 and 35°C and pH 5.6, appreciable growth of L. monocytogenes occurred at all test concentrations of sorbate. Reducing the pH to 5.0 allowed limited growth of the pathogen at 21 and 35°C when the medium contained 0.05, 0.1 or 0.15% potassium sorbate. Higher concentrations caused either complete inhibition or inhibition plus partial or complete inactivation of L. monocytogenes .
使用添加了0、0.05%、0.1%、0.15%、0.2%、0.25%或0.3%山梨酸钾的胰蛋白胨肉汤，将pH值调至5.6或5.0，并在4℃、13℃、21℃或35℃下培养，研究了山梨酸对单核细胞增生李斯特菌的抑制和灭活作用。除了在4℃和pH值为5.0的条件下，该细菌在无山梨酸盐的对照中在所有条件下均能生长。在pH值为5.6和4℃时，66天和60天后，0.25%或0.3%的山梨酸钾可使该细菌失活。其他浓度允许轻微生长，随后菌数减少。在4℃和pH值为5.0时，0.15%至0.3%的山梨酸钾浓度可在60至36天内使病原体完全失活，而其他浓度在培养期间导致菌数逐渐减少。在13℃和pH值为5.6时，单核细胞增生李斯特菌在所有测试的山梨酸钾浓度下均能生长，但最大菌数与添加到培养基中的山梨酸钾浓度直接相关——浓度越高，最终的最大菌数越低。在13℃和pH值为5.时，0.2%、0.25%或0.3%的山梨酸钾浓度可完全抑制生长并使病原体完全失活，而山梨酸钾含量为0.15%或更低时允许病原体生长。在21℃和35℃以及pH值为5.6时，在所有测试的山梨酸盐浓度下，单核细胞增生李斯特菌均有明显生长。当培养基中含有0.05%、0.1%或0.15%的山梨酸钾时，将pH值降至5.0可使病原体在21℃和35℃下有限生长。更高的浓度会导致单核细胞增生李斯特菌完全抑制或抑制加部分或完全失活。
