Relative Cleanability of Various Stainless Steel Finishes after Soiling with Inoculated Milk Solids

Open Access
Publisher Website
Google Scholar
Abstract
Mill samples of No. 2B, 3, 4 and 7 finishes of Type 302 stainless steel were obtained from the major stainless steel manufacturers to provide representative samples for relative cleanability studies. Sterile skim milk, inoculated with Bacillus globigii spores, was employed as a soiling medium. Relative cleanability was measured after rinsing (T-2), rinsing and washing (T-3), and rinsing, washing, and sanitizing (T-4). A special automatic spray-washing device was developed to provide carefully controlled rinsing and washing techniques. Bacterial cleanability was measured by the direct surface agar plate test (DSAP), the swab contact test, and the direct contact plate test. The DSAP detects the number of bacteria remaining on the surface of the material being tested; the latter 2 tests detect only the bacteria removed from the surface by the specific test procedure. The Duncan Multiple Range Test was employed to group the data; no significant difference in bacterial cleanability was noted at the 5% level regardless of the bacteriological test and/or cleaning treatment. An analysis of variance indicated no significant difference in the bacterial cleanability of a No. 2B, 3, 4 and 7 finish after T-2, T-3 or T-4 when the DSAP test was employed.

This publication has 5 references indexed in Scilit: