Cleaning Process

i. Steps Involved

The modern cleaning agents used in a food processing plant are complex combinations of chemicals mixed in order to achieve specific functions. Four fundamental steps involved in any cleaning process are:

• Dislocating the solid and liquid soils from the surface to be cleaned by saponifying the fat, peptizing the proteins and dissolving the minerals;
   Scattering the soil in the solvent by dispersion, deflocculation or emulsification; and
•  Preventing re-deposition of the dispersed soil back onto the clean surface by providing good rinsing properties.
• Bringing the detergent solution into close contact with the soil to be removed by means of good wetting and penetrating properties;

ii. Qualities of a Good Detergent

In addition to achieving these essential steps, a good cleaner should:

•  Soften the water adequately;
•  Dissolve quickly and completely;
•  Be non-corrosive;
•  Be non-toxic;
•  Be economical
•  Remain stable upon storage and
•  Be non-caking and non-dusting.

It is obvious that no single chemical can satisfy all these criteria. Therefore, a cleaning solution is generally made up of several ingredients, each one having one or more of these properties. The selection of the compounds to be blended into a good cleaner requires highly specialized knowledge. The different ingredients of cleaning compounds are combined in such a manner so as to assure the following functions:

Deflocculation: Breaking up of soil flocs on surfaces to improve removal of the soil.

Dispersion: The power to scatter and flocculate so that mineral films are not redeposited on the surface from which they are removed.

Dissolving: The ability to dissolve both inorganic and/or organic solids so as to speed their transfer into solution.Emulsifying,

suspending: The power to emulsify fat and suspend other solids in solutions.

Peptizing power: The ability to attack and disperse protein by hydrolyzing it.

Rinsing power: The ability to separate dirt/soil from the surface to which it has been adhering when fresh water is flushed over the surface.

Saponifying power: The capacity to turn fats into soaps.

Sequestering: The ability to prevent deposition of undesirable mineral salts on surfaces being cleaned.

Wetting: The capacity to lower the surface tension of the water medium so as to increase its ability to penetrate soil/dirt.

 

iii. Classification of Detergents

The chemicals used as cleaning compounds can be grouped into five basic classes:Alkalis, complex (or poly) phosphates, surfactants, chelating compounds and acids.Their general functions are listed in below  Table 

Classification of cleaning compounds and their major functions

The different classes of cleaning compounds vary in the efficiency of their actions,as listed in Table

Relative efficiency of the different classes of cleaning compounds