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Cleaning & Disinfection
FOOD TECHNOLOGY, HYGIENE & SAFETY (DEMT 2333)
DIPLOMA IN ENVIRONMENTAL HEALTHVICTORIA INTERNATIONAL COLLEGE
BY: MR KHAIRUL NIZAM MOHD ISADEPARTMENT OF ENVIRONMENTAL HEALTH
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INTRODUCTION
Objective of clean depend on standard requirement
aesthetic clean (appearance only)
physical clean
microbiological clean (high-risk food):
x Cleaning
x Disinfection
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Other costs:
poor quality product shelf-life
customer complaint, loss reputation
food poisoning
wastage
taint, contamination
corrosion equipment replacement
breakdown NaOH remove grease from bearings
deterioration of floor surface, drain
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Management functions of cleaning
Commitment
Required standards clearly defined, communicated, reinforced
Provide means
adequately trained cleaning staff, supervise, supplied with
appropriate materials and equipment. Minimize different
cleaning agents
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Cleaning schedules
communication link between management and staff
planning schedule should consider:
size, type, temperature of area, structure of building, wall,
floor and ceiling finishes
type of equipment and material
whether equipment can be dismantled type of soiling
presence of electrics
water pressure, drainage system
time constraints, manpower and training needs if cleaning necessary during food preparation required
disinfection?
Requirements underHealth and Safety Act
Controls available to monitor effectiveness of cleaning
Overall cost e.g. labour, equipment, chemicals, water, heat
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Specify:
what is to be cleaned
who is to clean
when to be cleansed
how is to be cleaned
time necessary to clean it
chemicals, material, equipment
cleaning standards
precautions
protective clothing
who to check and record that it has been cleaned
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Administration
Select chemical supplier -
x cheap chemical ? expensive cleaning
x have expertise to demonstrate how to use product with
best effect
Stock control
Distribution transfer right materials, right quantity,
right people, right time
Financial control
rotation, delivery check, inventory control
records
Expenditure
area of use
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TECHNOLOGY OF CLEANING
Cleaning - systematic application of energy to a surface or
substance, with intention of removing dirt.
Energy in cleaning -
1. kinetic energy:a) physical - manual labour
b) mechanical -machines
c) turbulence -liquids (CIP)
2. thermal energy: hot water 3. chemical energy: detergents
Combination of 2 or more energy. Manual labour most
expensive. Adequate contact time important. Correct energy
balance (cost-effective cleaning)
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Cleaning costs:
*If wrong chemicals corrosion costs
Labour 70% Chemicals 6%
Equipment 12% Heating 4%
Water/effluent 6% Corrosion 2%
If buckets and mops
used only :
equip. cost
lower equip cost but labour cost
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Chemical cleaning
Detergents - soaps
Alkaline - caustic soda corrosive to skin, Al, zinc,
good for fat, protein
Acid - remove mineral, protein, veg. Phosphoric acid
(least corrosive)Toxic release Cl2 gas not use with chlorinated
Powder
Liquid
Foam
gel
reduce surface tension, breakup
matter to smaller particles
suspended easily rinsed
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Surfactancy
Property of detergent which enables to increase the wetting
power of water by reducing the surface tension. This
increase he contact between the soil and the detergent
solution which is able to penetrate the minute irregularitiesof the dirt more effectively.
Dispersion
This is the ability of a detergent to break up large
accumulations of matter into smaller particles. Suspension
When dirt is broken up into particles, they become coated
with a thin film detergent which keeps the particles apart
and buoyant allowing them to be rinsed away.
(emulsifying action of detergent)
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Alkaline detergents
Commonly uses: caustic soda (sodium hydroxide)
corrosive to skin.
Aluminum and zinc has poor wetting properties, but is
effective for fat and protein solubility and is relativelycheap.
Sequestering agents (chelates) such as amino carboxylic
acids, EDTA and NTA are added to prevent scale formation
in hard water. Acid detergents
Mainly used to remove mineral, protein and vegetable
deposits.
Contain phosphoric acid
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Detergent action
Grease on
Surface
Detergent
penetration
Globule
formedGlobule
formed
Globules in
suspension
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Types of soil
Organic - living matter e.g. animal fat, veg.Oil, starch, sugar,
protein from milk, egg, meat or blood
remove by neutral or alkaline detergent
If heated, dried or allowed to remain for prolonged period
alkalis must be used to remove them
Grease or oil is heated form a tenacious, dark, sticky
deposit known as polymerized grease.
Further heating of polymerized grease results in the
formation of carbon removed by caustic alkalis suchsodium hydroxide or potassium hydroxide.
Tannin which derived from tea, coffee or wine removed
by an oxidizing agent such as sodium hypochlorite (bleach)
or sodium perborate. If present with water hardness salt
use an acid detergent.
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Inorganic
Water hardness salt (scale)
oxidised metal (rust)
uric acid salts (urinal stain)
beerstone
calcium salt from milk (milkstone)
Removed by acids such as
hydrochloric & phosphoric
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Thank You