STM3113

CLEANING AND SANITIZING PRINCIPLES

By:Dr. Mohd Nizam Lani

What is “Sanitation”?The process of creating conditions that

promote the safe production of food

A Hidden Hazard: Food Allergens

Foods must be labeled accurately

Effective cleaning procedures eliminate residues that cause food allergies

Why is Sanitation so important? Many cases of foodborne illness are associated with sanitation problems.

The complete sanitation process will reduce bacteria and viruses that cause foodborne illness. Essential to programs such as HACCP.

Ensures quality and consistency of food products.

Controls allergen cross-contamination.

A Hidden Hazard: Food Allergens

Proteins some foods cause allergic reactions

Eight food groups cause 90% of food allergic reactions Milk, eggs, peanuts,

tree nuts, wheat, soy, fish, shellfish

Cleaning and Sanitizing Cleaning and sanitizing most important aspect in sanitation prog. Procedures must be developed for : food-product contact surfaces (equipment, utensils, etc) non-product surfaces (shields, walls, ceiling, etc) Cleaning => complete removal of food soil using appropriate

detergent chemicals under recommended conditions Sanitizer => any agent that reduce the bacterial count to safe

levels to inanimate objects based on public health requirement Disinfection The killing of organisms by chemical or physical means The official definition (AOAC) of sanitizing for food product

contact surfaces process which reduces the contamination level by 99.999% (5 logs) in 30 sec.

Sanitizing non-product contact surfaces -> requires a contamination reduction of 99.9% (3 logs). Std organism: S.aureus & E.coli

Cleaning and Sanitizing (con’t) Objective of cleaning and sanitizing: (i) To remove food (nutrients) which bacteria need to grow (ii) To kill those bacteria which are present Cleaning frequency must be clearly defined The type of cleaning required must be identified. It is important that the clean, sanitised equipment and

surfaces drain dry. Necessary equipment must be clean and stored in a

clean, sanitary manner. Cleaning/sanitizing procedures must be evaluated. Adherence to prescribed written procedure continuously

monitored and record maintained to evaluate long-term.

Multiple Step Process in Cleaning and Sanitizing

1.Pre-cleaning – Scrape and rinse to remove loose food.2. Wash - Use detergent solutions to remove stuck- on food.3. Rinse to remove food and detergent.4. Sanitize to kill attached surviving bacteria and viruses.5. Air Dry.

The Process

Cleaning Methods

• Manual Cleaning in Equipment sink Requires total disassembly for cleaning and inspection

•Mechanical Cleaning or Clean-in-Place

Required no disassembly or partial disassembly•Clean-Out-of Place (COP)

Can be partially disassembly for cleaning and inspection

PROPERTIES OF FOOD SOIL- Food Soil --> Unwanted food residue, organic or inorganic

matter remaining on equipment and other surfaces- Soil is visible or invisible- Primary source from the food product being handled- Minerals from water residue and residues from cleaning

compounds contribute to films left on surfaces.- Microbiological biofilms also contribute to the soil build-up

on surfaces.- Soils vary in composition no detergent capable to

remove all types of soils.- Complex films (combination of food components, surface

oil or dust, insoluble cleaner and insoluble hard water salts) vary in their solubility properties

THE RULE OF THUMB – CHOOSING THE RIGHT SANITISER

- Acid cleaners dissolve alkaline soil- Alkaline cleaners dissolve acid soil- Improper use of detergents can actually ‘set’ soil making

them more difficult to remove - Soils can be classified as: (a) soluble in waters (sugars, some starches, most salts) (b) soluble in acid (limestone and most mineral deposits) (c) soluble in alkali (protein, fat emulsions) (d) soluble in water, alkali or acid- Physical conditions of the soil deposits will affect its

solubility.- E.g. Freshly precipitated soil in a cold conditions is usually

more easily dissolved than an old, dried or baked-on deposits or a complex film.

CLASSIFICATION OF SOIL

Fat-based Soils Fat usually is present as an emulsion and can generally be rinsed away with hot water above the melting point. More difficult fat and oil residues can be removed with alkaline detergents which have good emulsifying or saponifying ingredients.

Protein-based Soils In the food industry, proteins are by far the most difficult soils to

remove. In fact, casein (a major milk protein) is used for its adhesive properties in many glues and paints.

Food proteins range from more simple proteins, which are easy to remove, to more complex proteins, which are very difficult to remove.

Heat-denatured proteins can be extremely difficult. Generally, a highly alkaline detergent with peptizing or dissolving

properties is required to remove protein soils. Wetting agents can also be used to increase the wettability and suspendability of proteins. Protein films require alkaline cleaners which have hypochlorite in addition to wetting agents.

Carbohydrate-based SoilsSimple sugars are readily soluble in warm water and are quite easily removed. Starch residues, individually, are also easily removed with milddetergents. Starches associated with proteins or fatscan usually be easily removed by highly alkaline detergents.

Mineral Salt-based SoilsMineral salts can be either relatively easy to remove, or be highly troublesome deposits or films. Calcium and magnesium are involved in some of themost difficult mineral films. Under conditions involving heat and alkaline pH, calcium and magnesium can combine with bicarbonates to form highly insoluble complexes. Other difficult deposits contain iron or manganese. Salt films can also cause corrosion of some surfaces. Difficult salt films require an acid cleaner (especially organic acids which form complexes with these salts) for removal.Sequestering agents such as phosphates or chelating agents are often used in detergents for salt film removal.

PHYSICAL AND CHEMICAL CHARACTERISTICS

Physical characteristic: particle size, shape and density

Chemical characteristic: surface tension, wetting power and chemical reactivity with the surface of attachment

CLEANING OPERATION

EASE OF SOIL REMOVAL DEPENDS ON THE SURFACE CHARACTERISTICS

1. Separating the soil from the surface material or equipment to be cleaned

Soil and surface must be thoroughly wet Cleaning compound (CC) reduces the strength of the

bond between soil & surface Heat or mechanical action (scrubbing, shaking or

high pressure spray) can help to reduce the strength of the bond

2. Dispersing the soil in the cleaning solution

Diluting soil in the cleaning solution More soil need more cleaning solution As cleaning solution becomes saturated with soil,

fresh cleaning solution need to be used Some soil that have been loosened from the surface

will not dissolve in the cleaning solution Important to break up the soil into smaller particles or

droplets that can be carried away from the cleaned surface

Mechanical energy (shaking, high pressure water or scrubbing) help cc break down the soil into small particles

3. Preventing dispersed soil from reattaching the surface

Cleaning method should: Removed the dispersed solution from the surface

being cleaned Shake the dispersed solution to stop the soil from

settling Prevent reactions between the cc & water on the soil Flush or rinse the cleaned surface to remove all

dispersed soil & cleaning solution residues Keep the soil finely dispersed so that it does not

become trapped on the cleaned surface

CLEANING COMPOUND

FUNCTIONS AND CHARACTERISTICSCLEANING MEDIA Water – most frequently used Air – removal of packaging material, dust and

other debris Solvent – removal of lubricants & other similar

petroleum pdts

MAJOR FUNCTIONS OF WATER AS A CLEANING MEDIUM

Pre rinse for the removal of large soil particles Wetting (softening) of soils on the surface when

removal is essential Transport of the cc to the area to be cleaned Suspension of the soil to be removed Transport of suspended soil from the surface being

cleaned Rinsing of the cleaning compound from the area being

cleaned Transport of a sanitizer to the cleaned area

WATER CHARACTERISTICS

Free of m/o Free of minerals

Water hardness Mineral content (ppm) Very hard > 180Hard 120 - 180Moderately hard 60 - 120Soft 0 - 60

CC CHARACTERISTICS

How CCs function?? The major functions of a cc are to lower the surface tension of

water so that the soils may be dislodge and loosened and to suspend soil ptles for subsequent flushing away

Best known CCs: plain soap but of limited use A basic soap contributes to cleaning thru the removal of fats,

oils and greases by suspending ptles of these water-insoluble materials

After fat or oil has been suspended, removal by flushing is easy, although a residual film will exist

The suspension process of water-insoluble materials thru interaction with soap emulsification

Fat/oil soluble

Hydrophobic endLong chain hydrocarbon

Hydrophilic end(water-soluble)

ANIONIC SURFACTANT MOLECULE

FACTORS AFFECTING CLEANING PERFORMANCE

Time Contact time on the surface being cleaned Action Physical force exerted onto the surface (velocity or flow) Concentration Amount of cleaner used Temp Amount of energy (heat) used in cleaning solution Water Used to prepare cleaning solution

Individual Worker performing clean-up operation

Nature Composition of soil

Surface What material is being cleaned

TERMINOLOGY (chemical functions)

Chelating agent An additive used in CCPs that prevent hardness

constituents and salts of ca & mg from deposition on equipment surface by binding these salts to their molecular structure. These agents can also bind other ions

Emulsification A complex action consisting of a physical b/down of

fats and oils into smaller particles that are dispersed throughout the medium. The soil is present but reduced in physical size.

Peptizing A process that involve the formation of a

colloidal solution from a material that is partially soluble, by the action of alkaline materials on protein soils

Rinsibility The ability of a cc to be removed easily from a

surface with a minimal amount of residue

Saponification The action of an alkaline material on an insoluble soil (i.e. animal fat or

veg oil) to produce a soluble crude soapSequestrant An inorganic ingredient that is blended with ccps to prevent the

precipitation of unstable salt that contributes to water hardness. These unstable salts will b/down in the presence of alkaline cmps or at a high temp.

Many alkaline ccps are more effective with an elevated temp, however a high temp cleaning solution contributes to precipitation of ca & mg carbonates, commonly known as scale.

A sequestrant agent a chemical agent that ties up ca & mg ions in a solution to prevent the ions from forming insoluble curds with the cleaning detergent, which result in precipitation deposits

Surfactant A complex molecule that when blended with a cc, reduces the

surface tension of water to permit closer ctc between the soil deposit and cleaning medium

Suspension A processs by which a cc loosens, lifts and holds soil ptls in

solution

Wetting (penetration) Caused by the resultant action of a surfactant that due to its

chemical structure, is capable of wetting or penetrating the soil deposit to start the loosening process from the surface

Water hardness

The amount of salts such as calcium chloride, mg chloride, sulfates & bicarbonates present in water

Permanent hardness: referring to Ca & Mg chlorides and sulfates in water (rather stable & soluble under most conditions causing minimal problems with cleaning)

Temporary hardness: caused by the presence of Ca & Mg bicarbonates (relatively soluble but unstable) – cause white deposits on equipment, heat exchangers & water utensils

TH + pH = TOTAL HARDNESS

WATER SOFTENING

Condition caused by the removal or inactivation of the ca & mg ions in the water

Accomplished by chelation, precipating ca & mg as insoluble salts thru a precipating agent such as trisodium phosphate, and by ion exchange involving replacement by commercial water softness.

CLASSIFICATION

a) Alkaline cleaning cmpsDivided into:

Strongly alkaline cleaners Heavy-duty alkaline cleaners Mild alkaline cleaners

i) Strongly alkaline cleaners Have strong dissolving powers, very corrosive Prolonged contact/inhalation-permanently damage

tissue & respiratory tract damage Remove heavy soils from commercial ovens & smoke

houses Little effect on mineral deposits Not used as manual clenaer Eg; Caustic soda (NaOH)

ii) HEAVY-DUTY ALKALINE CLEANERS Moderate dissolving powers, slightly

corrosive and non-corrosive Prolonged contact-remove necessary oils

from the skin (subject to infections) Remove fat but not mineral deposit Active ingredients: Sodium

hexametaphosphate, sodium pyrophosphate, sodium bicarbonate & trisodium phospate

iii) MILD- ALKALINE CLEANERS

Frequently exist in solution Used for hand-cleaning of lightly soiled areas Cannot remove mineral deposits Eg: Sodium bicarbonate, surfactants, sequesters

b) Acid cleaning compound

i) Strongly acid cleaner Corrosive to concrete, most metals & fabrics Produce toxic gases, ulcerate the lungs Remove mineral deposits on boiler, steam

equipment etc Eg: HCL, H2SO4, hydrofluoric

ii) MILDLY ACID CLEANERS

Mildly corrosive, may cause allergic reaction

Acts as a water softener Eg: Levunic acid, hydroxyacetic acid,

acetic & gluconic acids.

c) SOLVENT CLEANERS

Normally used on petroleum-based soils, greases & lubricating oils

Based on ether or alcohol Used in the maintenance shop & on motors,

gear boxes, pallet trucks & fork trucks May be mixed with wetting agents, water

softener & other additives

d) SYNTHETIC DETERGENTS

The same function as soap-emulsification of fats, oils & greases (no curd formation)

Hydrophilic end soap curds in hard water but not synthetic detergents

Effective because lowers the surface tension of the solution, promotes wetting of the particles & deflocculates & suspends soil ptls.

e) ALKALINE SOAPS

Soap created by rxn of an alkali cmpd with fatty acid

Commonly use: lauric (C12), stearic (C18) Not used much in the industrial cleaning

because less effective in hard water & inactivated by acid solutions

f) DETERGENT AUXILLARIES

Additives included in the cc to protect sensitive surfaces or to improve the cleaning properties of the cmpd.

2 types i) protection ii) Cleaning

i) Protection

Acid cmpd: clean alkaline-sensitive surface & light metal cleaning

Protective colloids & suspending agents: prevent prtle redeposition on the cleaned surface

ii) Cleaning Sequestrants (aka chelating agents) Surfactants: cationic, anionic, nonionic, amphoteric

g) SCOURING COMPOUNDS

Aka chemical abrasives 2 types:

Slightly alkaline: remove light deposit soil Neutral: made from volcanic ash, silica flour

for manual scrubbing

SELECTION

The types of soil determines which cc can be used most effectively, depends on:

1. Soil deposition2. Temp & conc of cc solution3. Cleaning time4. Mechanical forced used

HANDLING AND STORAGE PRECAUTIONS

Compounds must be kept at proper place (dry floor, moisture-free air, moderate temp, remote place

Storage area should be locked Use of inventory sheet Use safety clothing Workers wearing contact lenses should not work with

chemicals Always follow manufacturer instruction for mixing of

cmpds