Temperature measurement Fig 14.1 Recommended position for taking deep leg temperatures in a chilled beef carcass(source: Meat Research Corporation, 1995b) or meat products is a straightforward if time-consuming process. Tempera ture sensors have to be inserted and positioned close to the thermal centre prior to freezing. The samples are then packaged with the sensor leads ealed into the packs. If further information is required then additional sensors can be inserted close to the surface and at other positions of inter est. With packs of small individual items care must be taken to maintain the position of the sensor within the pack when it is moved. Fixed or portable data loggers are then used to record temperatures during the freezing process, and throughout distribution if required, and the resulting data are Routine determination of the temperature of frozen foods in the cold hain is a much more difficult process. Making a hole 2.5cm or 3-4 times the probe diameter deep and then inserting a temperature probe sounds easy, but in practice is much more complicated. There are three basic methods of making the hole: (1) forcing in a sharp ened pointed instrument, (2) screwing in an auger-type bit or 3)drilling a hole. All cause problems with different types of frozen produce Forcing a pointed instrument into frozen food at -18C requires considerable force and the product has to be secured on a firm base to stop it slipping and to provide the resistance required. Fragile products such as beefburgers, pies, and so on will readily shatter when subjected to such treatment. An auger is better but the product still has to be restrained. Holding down a smallor meat products is a straightforward if time-consuming process. Tempera￾ture sensors have to be inserted and positioned close to the thermal centre prior to freezing. The samples are then packaged with the sensor leads sealed into the packs. If further information is required then additional sensors can be inserted close to the surface and at other positions of inter￾est. With packs of small individual items care must be taken to maintain the position of the sensor within the pack when it is moved. Fixed or portable data loggers are then used to record temperatures during the freezing process, and throughout distribution if required, and the resulting data are analysed. Routine determination of the temperature of frozen foods in the cold chain is a much more difficult process. Making a hole 2.5 cm or 3–4 times the probe diameter deep and then inserting a temperature probe sounds easy, but in practice is much more complicated. There are three basic methods of making the hole: (1) forcing in a sharp￾ened pointed instrument, (2) screwing in an auger-type bit or (3) drilling a hole. All cause problems with different types of frozen produce. Forcing a pointed instrument into frozen food at -18 °C requires considerable force and the product has to be secured on a firm base to stop it slipping and to provide the resistance required. Fragile products such as beefburgers, pies, and so on will readily shatter when subjected to such treatment. An auger is better but the product still has to be restrained. Holding down a small Temperature measurement 293 Fig. 14.1 Recommended position for taking deep leg temperatures in a chilled beef carcass (source: Meat Research Corporation, 1995b)