Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8891305 | LWT - Food Science and Technology | 2018 | 9 Pages |
Abstract
Water activity (aw) influences the thermal resistance (D-value) of pathogens in low-moisture foods (LMF). However, the influence of food matrices on aw at elevated temperatures is complicated. A recent study reported that a novel thermal water activity cell (TAC) could be used to control aw 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 (aw at room temperatureâ¯=â¯0.45) were treated in TAC II at 80â¯Â°C under controlled relative humidity (RH) (50%) provided by LiCl solution (9.37â¯molâ¯kgâ1). Results showed that the moisture-equilibrium was established to the controlled RH condition at 80â¯Â°C in <4â¯min for tests with TAC II, as opposed to >14â¯min for TAC. The D-value of Salmonella PT30 in WF (80â¯Â°C, RH 50%) tested with TAC II (20.7â¯Â±â¯1.1â¯min) was significantly higher (pâ¯<â¯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 aw (corresponding RH) at high temperatures on the D-values of Salmonella in LMF.
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Authors
Ravi Kiran Tadapaneni, Jie Xu, Ren Yang, Juming Tang,