Abstract:
The evaluation of residual protein test kit (ProAlert) to be used as a tool for cleaning validation was carried out. Results from ProAlert were compared with those analyzed by total organic carbon (TOC) method. The detection sensitivities of the test methods were compared using bovine serum albumin (BSA) at 10-1,000 ppm (0.1 ml) and Pseudomonas aeruginosa (1-5 logCFU/ml) at 0.1 ml as test samples. The reaction times were 10, 20 and 30 min before the readings were taken. It was found that color development of ProAlert changed from green to light gray in which A562 of 0.09 equivalent to BSA of 43, 34 and 27 ppm with reaction times of 10, 20, and 30 min, respectively. The recovery rates of ProAlert were 99, 96, 81, and 79% for BSA of 10, 30, 50, and 70 ppm, respectively. They were not significantly different among reaction times of 10-30 min. However, at high BSA concentrations of 100, 300, 500, 700 and 1,000 ppm, the recovery rates were 75, 53, 49, 46, and 42% when results were read in 10 min while the recovery at 20 and 30 min were 79, 62, 58, 56, and 51%; and 79, 72, 67, 65, and 59%, respectively. The TOC method gave more than 90% recovery rates on all BSA concentrations. P. aeruginosa at all concentrations tested did not give color change of ProAlert. When ProAlert and TOC were applied in a chicken meat factory, it was found that TOC values before and after cleaning were 6,142 and 0.26 ppmC, respectively. The reduction was more than 1,000 times indicating the effective cleaning process. ProAlert could detect residual protein after cleaning of 3.2 ?g/100 cm2 with color change in 25 min. ProAlert appeared to be a reliable tool for cleaning validation compared with the standard TOC method.