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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