Water activity (a_w) influences the thermal resistance (D-value) of pathogens in low-moisture foods (LMF). However, the influence of food matrices on a_w at elevated temperatures is complicated. A recent study reported that a novel thermal water activity cell (TAC) could be used to control a_w of LMF using LiCl solution (select molality) during the isothermal determination of D-values of Salmonella. This research proposed a new version of TAC (TAC II) that could significantly reduce the time to establish the moisture-equilibrium between LMF and LiCl solutions during D-value measurements. Wheat flour (WF) samples inoculated with Salmonella (a_w at room temperature = 0.45) were treated in TAC II at 80 °C under controlled relative humidity (RH) (50%) provided by LiCl solution (9.37 mol kg⁻¹). Results showed that the moisture-equilibrium was established to the controlled RH condition at 80 °C in <4 min for tests with TAC II, as opposed to >14 min for TAC. The D-value of Salmonella PT30 in WF (80 °C, RH 50%) tested with TAC II (20.7 ± 1.1 min) was significantly higher (p < 0.05) than the reported result obtained from TAC. TAC II provides more accurate estimation of D value for giving relative humidity at high temeprature, and it offers to improve our understanding of the isolated effect of a_w (corresponding RH) at high temperatures on the D-values of Salmonella in LMF.

水分活度（a _w）影响低水分食品（LMF）中病原体的耐热性（D值）。然而，在高温下，食物基质对_w的影响是复杂的。最近的一项研究报道，在等温测定沙门氏菌D值的过程中，可以使用新型的热水活度池（TAC）使用LiCl溶液（选择摩尔浓度）控制LMF的_w。这项研究提出了一种新版本的TAC（TAC II），它可以大大减少在D值测量期间在LMF和LiCl溶液之间建立水分平衡的时间。小麦粉（WF）与接种的样品沙门氏菌（一_瓦特在室温下= 0.45）在TAC II中于80°C的LiCl溶液（9.37 mol kg ^-1）提供的受控相对湿度（RH）（50％）下进行处理。结果表明，使用TAC II进行测试时，在<4分钟内在80°C下于80°C建立了湿度平衡，而TAC> 14分钟则达到了。用TAC II（20.7±1.1分钟）测试的WF（80°C，相对湿度50％）中沙门氏菌PT30的D值显着高于 从TAC获得的报道结果（p <0.05）。TAC II可以更准确地估算D值，以提供较高温度下的相对湿度，并且可以提高我们对高温下_w（对应的RH）对沙门氏菌D值的孤立影响的了解。 在LMF中。