are feasible.No vacuumpumpsare required,sincethe plasmais generatedat
normalatmosphericpressure.Thesedevelopmentswill giverise to newand
broader food processing related applications of the technology including
sanitizationof foodcontactsurfaces.
Coldplasmagaseshavebeen shown to haveantimicrobialactivityagainsta
widerangeof microorganisms.Roth(1998)has reported activityof cold plasma
against vegetative bacteria, bacterial spores, yeast, mold and viruses.
Inactivation timesfor many of thesemicroorganisms,on a variety of surfaces,
wereat leastthe equivalentof thosereported for conventionalthermaland
chemical methods. The mechanisms of inactivationare not fully understood.
Coldplasmatechnologyis still in development.If successful, this innovative
technology will offer the food industry a non-chemical, low-temperature
alternative meansof disinfection.
28.4.5 Post-sanitizingrinse
The final step in developinga COPwet-cleaningprocess involvesthe removal
and or inactivation of the sanitizing or disinfecting chemical. Becausemanyof
the chemicalsusedas sanitizingagents havetoxicproperties,it is necessary to
providemeasuresthat will eitherremoveor reduce the compoundsto safe and
acceptable levels.Because of theirtoxicity,many worldgovernmentshave
promulgatedregulations thatspecify allowable levels or maximum residue
levels (MRLs) for sanitizing chemicals and disinfectants. In the USA, for
example, this regulatory activity is administered jointly by the US
EnvironmentalProtectionAgencyand the US Foodand Drug Administration.
It is also noteworthythat the residues of certainsanitizers maycausetaints, off-
odors, and other unacceptableorganoleptic manifestationsin foodproducts.
Theseproduct quality-related changes are alsojustification for rinsingthe
sanitizerfromthe foodcontact surfacesof processingequipment.
The rinse step in COPcleaning is accomplishedmostoften by floodingor
immersing the sanitizedequipment in potablewater. The rigorrequired of the
post-sanitizingrinseis dependenton the toxicityof the compoundand the
requirementsfor its removalfromthe foodcontact surfaceof the sanitized
substrate. The rinsecyclemustensurethat carry-overof sanitizerintofood
production is consistentwithpublichealthand otherregulatoryrequirements.
28.5 Validation
TheCOP process is basedon a certain set of assumptionsrelated to the
manufacturingprocess.The assumptionsunderpinning the COPprocessrequire
validation. Thatis, the assumptions must be shownto be bothvalidand relevant
to settingthe parametersof the process.A COPprocessdevelopedaround faulty
assumptions will not be reliable. An effectiveprocess, COPor otherwise,must
yield predictable results. Validation requires documented evidence that a
Improvingcleaning-out-of-place(COP) 463