wellas the morehydrophiliccharacterof the substrate binding region probably
contributeto the alkalineactivityof the enzyme (Betzelet al., 1992).
32.3.4 Determinationof the enzymatic activity
Enzymes or enzymepreparations are marketed in differentforms,as granulates
and in liquidformand,depending on the producer, withdifferentactivesub-
stance concentrations. Owing to the highly complex composition of the
enzymes/enzyme preparations,it is nearlyimpossible to designate the absolute
concentrationin the individualproduct,and thusdeducethe enzymic quantity
required for practical use. During manufacture, standardized processesare
appliedfor detecting the activity of eachproduct batch.Onlyafterwards is the
batchproductadjusted to a guaranteed quantity of the active substance.For
example, for the enzyme Savinase the producerNovozymesA/Sindicates the
activity in KNPU/g (Kilo-Novo-Protease-Units/gram), which refers to the
degradation of dimethyl casein(DMC)at 50 ÎC, and a pH valueof 8.3.
To determine the enzyme activity by the user the enzyme producer
Novozymesindicatestwo different methods:
- The method2000-14216-01 (NovozymesA/S, Denmark, http://www.novozymes.com))
basedon the hydrolysisof the substrateN,N-dimethylcasein(DMC,delivered
Fig. 32.2 The enzymeSavinasewitha viewto the centralhelix.The activecentregets
its geometricstabilityfromthis helix,togetherwiththe Ca2-ionat the surface± closeto
the activecentre.The N-term,stabilizedby the Ca1-ion,is importantfor the enzyme
protection.The activityof the enzymeis controlledvia the availablecalciumof the cell or
the medium.For cleaningpurposesthe bondingof calcium,e.g. by complexingagents,
mustbe avoided(Betzel,2003).
Enzymatic cleaning in foodprocessing 525