(suchas milk)are adhesive; cleaninginvolvesreactionof the deposit into a
viscoelasticgel that adheres to the surface.This classification is useful as it
allowsdecisionsto be made aboutselectionof cleaning protocols. Useof
modifiedsurfacesshowsthat (i) the theoreticalminimumadhesion conditioncan
be foundin practice (at leastfor tomatodeposits) but that (ii) the effect of the
surfacedecreaseswithincreasing depositthickness, as wouldbe expected.
Workis currentlyunderwayat Birminghamto quantify the relationship
between the measured apparentadhesivestrengthand theoreticaladhesiveand
cohesive strength. This could enable understanding in more detail the
relationship between adhesion and deposit chemistry, and howto cleanmost
effectively.
29.6 Acknowledgements
We wishto acknowledgefinancialsupport fromthe UK Biotechnologyand
Biological SciencesResearch Council (BBSRC), DEFRA UK and the Food
ProcessingFaraday.
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