A retort on the use of retorts

Sir,Your story on the use of microwave pasteurisation at S&R Foods (Food Manufacture, May 2011) said products placed near the walls of retorts tend to be overcooked to ensure those nearer the centre are cooked. This is simply not the case with retorts, even if the technology between equipment is different.

Retort construction is governed by a strict set of manufacturing guidelines and subsequent distribution legislation on installation. This states that no part of a retort can be more than one degree Celsius different from any other part. Retort validation is carried out by a third-party expert, such as Professor Philip Richardson's team at Campden BRI.

Lagarde retorts, which are the UK standard for chilled meal pasteurisation, regularly achieve greater than 0.5°C distribution accuracy. This ensures there is statistical data to confirm the accuracy of cooking in a retort (as opposed to an oven) and, on that basis, I feel your article is a little misleading. In addition, the fan-assisted tubular construction of a retort, means all layers in a retort basket achieve the same cooking process, regardless of the position of the tray, as steam is a three-dimensional heating medium.

Everybody loves new technology (myself included) but I feel that it is important to ensure that the facts are presented in an unbiased way, especially when those facts have been validated by third-party specialists in the field.

Christopher Holland

md, Holmach