ACQUISITION, STORAGE, AND REVIEW OF SAFETY DATA FROM A COMMERCIAL SYSTEM FOR HIGH-TEMPERATURE, SHORT-TIME PASTEURIZATION

A high temperature, short time (HTST) pasteurization system was equipp ed with electronic sensors; to determine the temperature, pressure, fl ow rate, and position of the flow diversion valve. A computer for data acquisition was wired to the sensors to monitor and to record process ing conditions related to public health. The processing conditions wer e stored in safety files on the hard drive of the computer, transferre d weekly to a tape drive, and stored. The processing conditions of the HTST system were monitored for 270 d to determine the accuracy and re liability of the data acquisition system. The size of the HTST safety fries ranged from 6.2 to 9.1 MB when the sensors were monitored every second. The file size was reduced to <1.8 MB when the monitoring frequ ency was increased to every 5 s. To determine accuracy, the temperatur es recorded by the data acquisition system were compared with the temp eratures recorded by an electronic recorder controller. To determine r eliability, changes in the position of the flow diversion valve were e xamined to identify process deviations and were compared with the even t marker on circular charts. The review of the data file by the actual time method was an effective alternative to the electronic recorder c ontroller for monitoring the completeness of data in the safety files. Offline review to determine reliability required approximately 10 min /d of records.