Baumann Adam R, Martin Scott E, Feng Hao
Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, 486 Animal Sciences Laboratory, 1207 West Gregory Drive, Urbana, Illinois 61801, USA.
J Food Prot. 2005 Nov;68(11):2333-40. doi: 10.4315/0362-028x-68.11.2333.
Inactivation experiments with Listeria monocytogenes 10403S, an ultrasound-resistant strain, were conducted at sublethal (20, 30, and 40 degrees C) and lethal (50, 55, and 60 degrees C) temperatures in saline solution (pH 7.0), acidified saline solution (pH 3.4), and apple cider (pH 3.4) with and without application of ultrasound (20 kHz, 457 mW.ml(-l)). The survival of recoverable L. monocytogenes 10403S in apple cider was evaluated, and the effects of temperature, ultrasound, pH, and food matrix on inactivation were studied. Application of ultrasound increased the inactivation rate at both sublethal and lethal temperatures. Additional death of L. monocytogenes 10403S was due to low acidity at the lethal temperatures. The reduction in surviving L. monocytogenes 10403S followed first order kinetics at sublethal temperatures, but at lethal temperatures, a two-section linear model described the inactivation behavior. The bactericidal effect of thermosonication was additive in apple cider. The survival tests of L. monocytogenes 10403S in apple cider indicated the possibility of using a mild treatment condition in combination with ultrasound to achieve a 5-log reduction in number of listerial cells.
对耐超声波的单核细胞增生李斯特菌10403S株进行了灭活实验，实验在亚致死温度（20、30和40摄氏度）和致死温度（50、55和60摄氏度）下，于生理盐水（pH 7.0）、酸化生理盐水（pH 3.4）和苹果酒（pH 3.4）中进行，实验中分别施加和不施加超声波（20千赫，457毫瓦·毫升⁻¹）。评估了可恢复的单核细胞增生李斯特菌10403S在苹果酒中的存活情况，并研究了温度、超声波、pH值和食品基质对灭活的影响。施加超声波提高了亚致死温度和致死温度下的灭活率。单核细胞增生李斯特菌10403S在致死温度下的额外死亡是由于酸度较低。在亚致死温度下，存活的单核细胞增生李斯特菌10403S数量的减少遵循一级动力学，但在致死温度下，两段线性模型描述了灭活行为。在苹果酒中，热超声杀菌作用具有叠加性。单核细胞增生李斯特菌10403S在苹果酒中的存活试验表明，有可能使用温和的处理条件并结合超声波，使李斯特菌细胞数量减少5个对数级。
