distribution, package sterilization tech-
niques, and package residual. An on-line
continuous monitoring method is needed.
Several methods are available for measure-
ment of concentration levels of H 2 O 2 solu-
tions (Shapton and Shapton, 1991).
An efficient layout of cleaning equipment
is essential to reduce cleaning labor. It is
much easier to install cleaning equipment
when the processing equipment is put in
place. The type of soil found in fruit and veg-
etable processing plans is most easily cleaned
by portable cleaning systems in small plants
and by a combination of CIP and central-
ized foam cleaning in large plants.
Hot Water Wash
Water provides transport of cleaning com-
pounds and suspended soil. Sugars, other
carbohydrates, and other compounds that
are relatively soluble in water can be cleaned
rather effectively with water. The main
advantage of a hot-water (60 to 80°C) wash
for fruit and vegetable processing plants is
minimal investment of cleaning equipment.
Limitations of this cleaning method include
labor requirements, energy costs, and water
condensation on equipment and surround-
ings. This cleaning technique is not effective
in the removal of heavy soil deposits.
High-Pressure, Low-Volume Cleaning
High-pressure spray cleaning has utility in
the fruit and vegetable processing industry
because of the effectiveness with which
heavy soils can be removed. Difficult-to-
reach areas can be cleaned more effectively
with less labor, and there is increased effec-
tiveness of the cleaning compounds below
60 °C. Water temperature should not exceed
60 °C because high-temperature sprays tend
to bake the soil to the surface being cleaned
and to increase microbial growth. More dis-
cussion on this cleaning method is provided
in Chapter 11.
Foam Cleaning
Portable foam cleaning is widely used
because of the ease and speed of foam appli-
cation in cleaning ceilings, walls, piping,
belts, and storage containers in fruit and veg-
etable processing plants. Equipment size and
cost is similar to that of portable high-pres-
sure units.
Centralized foam cleaning applies clean-
ing compounds by the same technique used
in portable foam equipment. The equipment
is installed at strategic locations throughout
the plant. The cleaning compound is auto-
matically mixed with water and air to form
foam, which is applied at various stations
installed throughout the plant.Gel Cleaning
Here, the cleaning compound is applied as
a gel rather than as a high-pressure spray or
foam. Gel is an especially effective medium
for cleaning canning and packaging equip-
ment because it clings for subsequent soil
removal.Slurry Cleaning
This method is identical to foam cleaning,
except that less air is mixed with the cleaning
compound. A slurry is more fluid than foam
and penetrates uneven surfaces in a canning
plant more effectively, but it lacks the cling-
ing ability of foam.Combination Centralized High-Pressure,
Low-Volume and Foam Cleaning
This system is the same as a centralized
high-pressure, low-volume system, except
that foam can also be applied through the
equipment. This method is more flexible
because foam can be used on large surface
areas, and high pressure can be applied to
belts, stainless steel conveyors, and difficult-
to-reach areas in a canning plant.