MICROBIAL EVALUATION OF THE BIOTRANSFER POTENTIAL FROM SURFACES WITH BACILLUS BIOFILMS AFTER RINSING AND CLEANING PROCEDURES IN CLOSED FOOD-PROCESSING SYSTEMS
G. Wirtanen et al., MICROBIAL EVALUATION OF THE BIOTRANSFER POTENTIAL FROM SURFACES WITH BACILLUS BIOFILMS AFTER RINSING AND CLEANING PROCEDURES IN CLOSED FOOD-PROCESSING SYSTEMS, Journal of food protection, 59(7), 1996, pp. 727-733
The biotransfer potential in food processing is defined as the ability
of the microorganisms present on equipment surfaces both before and a
fter cleaning procedures to contaminate products during processing. Gr
owth of Bacillus biofilms was detectable on both stainless-steel and T
eflon(C) surfaces after all the cleaning procedures. B. cereus and B.
subtilis cells adhered more firmly to unsoiled than to soiled surfaces
, whereas B. thuringiensis adhered most firmly to soiled surfaces. The
results showed that the removal of biofilms from surfaces was more di
fficult from stainless steel because the microorganisms were attached
more tenaciously to rough surfaces. Biofilms were cleaned most effecti
vely from unsoiled surfaces with a simple rinsing procedure; thus the
mechanical forces of the flow are very important in the cleaning. The
chemical and heat treatments used for cleaning had the greatest impact
on the abundance of living microorganisms. All the procedures tested
did not remove biofilm material effectively from the surfaces. Signifi
cantly more cells were removed when the alkaline phase in the alkaline
-acid treatment of the cleaning-in-place (CIP) procedure was prolonged
, and ethylene diaminetetraacetic acid (EDTA) was used.