FEATURE
INCORPORATING COLD CHAIN
with refrigeration and air quality
management,” explains Dawie Kriel of
Energy Partners.
You require refrigeration for the three
main areas in the processing link of the
cold chain: in drop temp areas, cold
rooms, and freezers, explains Kevin Walter
of Lutz Refrigeration.
For drop temp areas, where the food
gets handled, you require between 10°C
and 15°C depending on the product,
advises Lutz. This is for working with any
perishables such as fruit, fish, or veggies.
Packaging for perishables must be done in a temperature-controlled environment. Taken at
Medallion Mushrooms.
Africa totalled EUR339-million in 2017,
which is 4% less than in 2016. However,
exports have the potential to pick up as
the packaged food and drinks market
expands across Africa.
TEMPERATURE MATTERS
Refrigeration is not negotiable for the
preservation of fresh and frozen food
products. “As fresh produce is harvested it
should be loaded into refrigerated areas
to be cooled to preserve quality, minimise
40
weight loss, and ensure extended shelf
life,” explains Christo van der Merwe of
MRE. Meat products must be maintained
below 10°C to prevent spoiling and
bacteria growth. “If the produce is not
cooled, then the shelf life is dramatically
reduced for most food products.”
Whenever the food gets in contact
with the environment, refrigeration is
needed. “Bacterial and fungi growth
are highly temperature and humidity
dependent and both can be controlled
In deboning rooms, for example,
the temperature is kept low (10°C) to
reduce the temperature rise while being
processed and the humidity low to
prevent condensation onto the product.
In terms of standards, the temperature
in drop temp areas should be around
10°C but generally, industry goes for
15°C (if the standard permits), as 10°C
is often considered ‘too cold’ by the
workers, explains Walter. However, for
pharmaceuticals, the regulations are strict
and temperatures must be kept between
2 and 8°C. This is heavily regulated.
As such, for pharmaceuticals, there is
generally full redundancy built into the
system because when the temperature
is out of range for as little as five minutes,
the product can be condemned.
During the packaging phase, 10°C
is also recommended for the product
www.coldlinkafrica.co.za
where it passes on conveyor belts,
explains Walter.
Refrigeration is necessary for the
manufacture of some products. “This
can be as diverse as fermentation
control in a winery or conversion of dairy
products into ice cream,” explains Nigel
Amschwand of GEA.
CHOOSING THE RIGHT
SYSTEM FOR THE JOB
Selection of HVAC&R equipment should
be done by a qualified specialist in these
cases, as normal climate control (air
conditioning) selection methods and
standard equipment probably won’t
apply, says Kriel. “Energy use, ease of
maintenance, and safety (especially of
staff) are the primary drivers for a low life
cycle cost system.”
The most common refrigeration systems
are either synthetic-refrigerant based for
commercial applications or ammonia based
for larger industrial applications, with CO 2
now becoming common in supermarket
applications, explains Van der Merwe.
The type of product you are cooling
will determine your system selection, says
Walter. For example, with bananas you
require higher humidity to prevent drying
of the product and weight loss; in this
instance, chilled water systems are ideal.
If you want really high humidity (up to
100% relative humidity), you should opt for
COLD LINK AFRICA • May 2019