The Development and Use of an α-Amylase-based Time–Temperature Integrator to Evaluate in-Pack Pasteurization Processes

A novel method to evaluate the applicability of time temperature integrators to different temperature profiles

“…Enzymatic TTIs are based on the quantification of the activity that remains after thermal treatment. Their high thermostability allows them to be used over a very wide range of temperatures (pasteurisation, sterilisation) (Guiavarc'h, Deli, Van Loey, Guiavarc'h, Van Loey, Zuber, & Hendrickx, 2004a;Guiavarc'h, Van Loey, Zuber, & Hendrickx, 2004b;Maesmans et al, 1994;Tucker, 1999;Van Loey, Arthawn, Hendrickx, Haentjens, & Tobback, 1997). Many studies on TTIs have used α-amylase from Bacillus spp.…”

“…Numerous enzymes have been identified for pasteurisation temperatures (Hendrickx et al, 1992;Tucker, 1999Tucker, , 2000Van Loey et al, 1997). However, finding an enzyme with the adequate thermostability at sterilisation temperatures (around 121°C) can be difficult.…”

Effect of heat on phycoerythrin fluorescence: Influence of thermal exposure on the fluorescence emission of R‐phycoerythrin

“…Predictions at temperatures of 62.5°C and above were in excellent agreement with the experimental data . This is important, since other researchers have reported systematic underpredictions of similar phenomena over wider ranges of temperature, primarily as a result of differences in the experimental protocols used to acquire isothermal and nonisothermal data (see, e.g., DeCordt et al, 1992;Van Loey et al, 1997). The experimental conditions for the two processes were different in this study also, with the isothermal experiments performed in capillary tubes in a water bath and the nonisothermal experiments in microtubes in a thermocycler.…”

“…As a result, challenge studies must be performed in pilot plants that may or may not have the same ovens or smokehouses used for the commercial process. Fortunately, a TTI can be used as a reliable thermal process monitor to mitigate these difficulties (DeCordt et al, 1992;Hendrickx et al, 1995;Van Loey et al, 1997). For example, TTIs can be used to verify, confirm, and/or complement challenge programs, even if they do not replace them.…”

A sterilisation Time–Temperature Integrator based on amylase from the hyperthermophilic organism Pyrococcus furiosus

“…Methods for kinetic data determination followed closely those reported by various research groups (De Cordt et al, 1992;Miles & Swartzel, 1995;Van Loey, Arthawan, et al, 1997). TTIs were attached to temperature probes and the temperature-time profile, T(t) recorded.…”