Room and Air Sanitation
Air is not a growth medium for microorganism,
but it contains particle material, dust, and drops of liquid which have
posibilities being inhabited by microorganism. The kinds and the number of the
microorganism are determined by environment pollution sources, e.g. human
respiration duct (cough and sneeze) and dust particles in the air. The
condition of the microorganism in air is dependent on the atmosphere condition
(humidity, sunlight, and temperature), size of the microorganism carrier
particle, and the identity of the microorganism, especially in collision
potency which is hardy in the physical condition in atmosphere. Microorganisms
in the air are microorganisms which is hardy of dry condition, e.g. mold
spores, bacteria spores adhering on dust or water drops, and also yeast.
Rate of air pollution by microorganism in room
is affected by factors like ventilation rapidity, the people density, and also
the kind and level activity of the people in that room. Microorganism
vilification could occure because of sneeze, cough, even when talking through
water drops medium. Drops of water which has diameter arround low micrometer
will live in the air for several time, but the big water drops will soon fall
down onto the floor or adhering on other things surfaces.
Earth surface (land and sea) is a
microorganism source in the air. The facilities of industry processing,
agriculture, and town, local or regional, also having potential producing
aerosol containing microorganism. A few examples are:
1. irrigation of farming plants or forest area
with waste.
2. implementation of big scale cleaning.
3. “trickling-bed” winnow in cleaning water
factories.
4. animal slaughtering house and fat melting.
Most of the microorganisms in the air are mold
spores, particularly from Aspergillus genus.
Beside that there are also spore former bacteria and non spore former bacteria,
bacillus positive gram, coccus positive gram, and bacillus negative gram.
Sanitation
Test on Surface
Tools sufaces which are directly having a
contact with food, for example processing preparation table, tank of raw
material/supporting material or package material, have a possibility being
contamination sources. Beside that food processing environment, e.g. floor,
wall or worker clothes is also having a possibility being contamination sources
in food. Because of that it needs appropriate methods to test the sanitation of
the surface, they are swab method and RODAC method.
Swab
Method
This method is usually using sterile spreader
stick which is available in market. Usually the spreader stick is made from
wood stick with cotton twist on the point. Beside that it needs sterile
thinning agent solution in tube (e.g. 10 ml) having a role as rinsing agent.
Spreader stick which has been used to smear, is placed into the tube containg
thinning agent solution. If needed, the point of the stick is cut, so that the
tube can be sealed.
RODAC
Method
RODAC or Replicate Organism Direct Agar
Contact is commonly used to know the condition of the flat surfaces sanitation
by sticking the agar on the surface for several seconds. It needs big syringe
(50 ml volume) containing PCA (Potato Dextrose Agar) (or other medium dependant
on the kind of the test) and being sterilized using otoklaf (121oC
for 15 minutes). Thus the solid medium is available in syringe (or known as
‘sausage agar’).
Every food processing process involves the
usage of tools and containers. If the cleaning of these stuffs is not conducted
well, so it is not impossible if the tools and the containers will become
contamination sources for processed food.
To test the containers and processing tools
sanitation, rinse method and swab method can be used. Rinse method can be used
for closed tools and containers, but swab method is for big tools and containers
with no flat surfaces.
Source:
Kusumaningrum H. D, dkk. 2007. Penuntun
Praktikum Mikrobiologi Pangan. Bogor: Institut Pertanian Bogor
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