Dairy and Meat Processing Plants:

Cleaning

By

Dr. Geeta ChauhanSenior Scientist

Division of Livestock Products Technology

Indian Veterinary Research Institute, Izatnagar, Bareilly (UP), India

IntroductionCleaning and sanitation has assumed key importance in fast growing food processing sector in response to enhancing demography with great impact on food behavior of consumers. Food legislations and regulations require the food processing industries to comply relevant food standards especially food safety standards. Growing awareness among consumers has also been proved as key drives for compliance of food safety standards.

Cleaning and sanitary practices are regarded as integral part of GMP and GHP, which is pre requisite of prevalent food safety management system like HACCP. Primary objective of cleaning and sanitation is to control access of microbes to food environment which has been bearing on public health aspect and efficiency of food processing operations. Neglection of hygiene measures results in unwanted costly product recall and shake of consumers trust.

Role of cleaning and Sanitation

• Meat and dairy products being rich in protein, low in acid and buffered, are very perishable and hygienically sensitive commodities.• Also, demands of livestock products are increasing with the growing income and urbanization. In response to growing demands, number of domestic and multinational food retail chain are catering the need of consumers especially in RTE segment.• Failure to observe the sanitary standards by these retail chain and processing industries may cause huge loss.• Due to the above facts, well planned cleaning and sanitary operations are necessary as they not only facilitate the compliance of legal standards o food but also create pleasant working environment for workers and minimizes the occupational hazards.

Cleaning

• Dirt, soil, organic matter protects the microbes from environmental stress particularly physical, chemical sanitizers used in food processing industries.• Cleaning refers to removal of soil, dirt which includes garbage, loose soil, milk, blood, fat residues, organic and inorganic deposits.• Cleaning is carried out prior to sanitizing process to achieve maximum efficiency of sanitizers.

Factors affecting the cleaning efficiency

There are many factors affecting the cleaning process efficiency and are needed to be considered before developing GMP and GHP for meat and dairy processing plants. Some of the important factors are-1.Sanitary design consideration of plant-Plant layouts and other details should be properly sanitary designed to achieve the goals of sanitation.Sanitary designs should take into consideration aspects like- interior and exterior of the plant, its location, waste disposal and drainage, construction material especially of food contact surface, separate clean and dirty areas.Spatial design should also be considered to access 360º to equipments and installation.

Also, factors like proper ventilation, air flow and lighting should be pay with due attention in sanitary design plan.

2.Sanitary design of tools and equipments-Sanitary design of tools and equipments facilitate easy and efficient cleaning.Dead spots or inaccessible spots on equipments and tools may serve potential source of contamination. So designing should eliminate the possibility of dead spots.

3.Material and state of food contact surface-Food contact surface must be of such materials to assure cleanliness and desired level of sanitation.Poorly maintained, cracked surfaces hinder the efficient cleaning operations and favor the biofilm formation.Scratch resistant material allows easy cleaning like stainless steel.

4. Quality of Air and Water- Water is used as a cleaning medium and chilling medium in

meat and milk processing. It is the most important detergent for cleaning and is used

at various stages for various purposes. It comes in contact of food, thus, act as a source of contamination of its quality is compromised.

Spray drying and air chilling require large volume of air which comes in contact of food and may have potential to contaminate.

Installation of air filter and maintenance of positive air pressure improves the cleanliness and sanitation.

Methods of Cleaning

• Cleaning process employs different types of detergent and energy in the form of pressure, hot water and physical removal like scrubbing, etc.• Cleaning method has evolved a lot to meet the demand of various product specific food industries

DETERGENTS • Cleaning efficiency is improved by employing chemical detergents.• Selection of detergent depends on factors like- nature of soil, corrosiveness property of detergent, rinsability, compatibility with other sanitizers and safety issues during handling of the detergent.• Detergent should be used in concentration just above the critical micelle concentration (CMC) that ranges 800 to 900 ppm.

Characteristics of Ideal Detergent

• It must possess capacity to form maximum suspension and deflocculation of soil.• Ability to prevent scale formation in hard water.• It must ensure optimum rinsing.• It must maintain relatively stable degree of acidity and alkalinity.• It should be compatible with sanitizers being used.• It should be non-toxic and should not tend to taint or discolor the food.• It should be bio degradable and economical

PRESSURE- Detergent solution is used with the range of 300 to 1000 psi pressure. Generally, high pressure jet cleaners are used in meat plant. Also, spray gun can be used effectively.

Pressure should be between 30 to 70 bar and nozzle should be 15 cm from the surface to be cleaned.

TEMPERATURE- Water with at least 82ºC with adequate pressure is capable of removing dirt and soil from surface. Also, if hot water is used, temperature at the nozzle at 55ºC is sufficient for fat removal. Pressurized steam and water mix is more efficient as impact temperature of approximately 100ºC can be achieved. Disadvantage- Fog and aerosol formation occurs which affects equipments and other installations due to excessive humidity and condensation.

Commonly Used Detergents

1.Alkaline detergent- Suitable to remove organic protein and fat.Sodium carbonate- efficient in dissolving in protein and fat but may cause corrosion in tools and equipments at pH 11 and above.

2.Acid detergent-Suitable to remove encrusted residues of soil or scale such as milk stones, lime and water stones, etc.

3.Neutral detergent-It has mild impact on skin and food contact surface material.Such detergents are useful for manual cleaning and of smooth surface without encrusted dirt.

Commercially available cleaning chemicals are complex compositions of alkaline, acid, neutral substances. Detergents may have additional cleaning substances like chlorine, silicate and phosphate. Alkaline and acid cleaners should be used alternatively. Alkaline detergent can be used for routine cleaning operation but acid detergent should be used after certain interval to remove encrusted scale.

Cleaning Process

• Periodical and frequent cleaning should be performed to check the build up of microbial niche.• Cleaning schedule depends on many factors like-a)Nature of the soil- food components determine the soil characteristics.

Protein is water soluble and slightly soluble in alkaline and acidic condition respectively whereas fat is soluble under alkaline condition.• Other factors are- nature of food contact surface desired cleanliness standards hardness of water nature of food products processed.

Basic Steps For Cleaning

• Cleaning process should start from dry cleaning to remove gross soil as it saves water and prevent clogging.• Wet cleaning with detergent remove the residual soil material which involves soaking, washing, non-abrasive brushing, rinsing followed by drying.

Care During Cleaning

All the food products must be removed from site because physical cleaning with pressurized water creates aerosols which is potential source of contamination.

Cleaning Operations In Meat Plant

• Hot water at 82ºC at final pressure at the hose nozzle with 14kgf/ sq cm is used with high pressure jet cleaners to wash and clean floor and other surfaces.• Trolleys, hooks, gambrel, etc may be sterilized in cabinets or in the sterilization room where they are immersed in batches in tanks.• Smaller items like meat knives, cleavers are sanitized in cabinet with hot detergent solution.

Novel Cleaning Method

Foam And Gel Cleaning

• Foam and gel adhere to the surface, allow more time to chemical to breakdown the soil which is then rinsed away with hot water under pressure.• Both cleaning methods are labor saving.• Foam is applied in cold form and gel can be applied in very hot form.• Gel, unlike foam, does not collapse and is useful for thin tenacious protein or fat films.

Advantages of Foam Cleaning

• It is labor saving and cover large area in very short time.• It can penetrate in accessible area of equipment, thus, dismantling of equipment is not needed.• Foam clings to surface and does not run to waste. Hence, it is economical.• It is bio degradable.• It is safe to use as does not splash during application.

Cleaning System

Various types of cleaning system exists in food processing units.

Cleaning In Place (CIP) system- It is a closed system.• Basically designed for cleaning internal surfaces only.• Here, compounds are circulated by a pump through series of pipes to the components to be cleaned.• Central cleaning system has a central pumping source supplying cleaning solution under pressure to remote locations.• Unit should create pressure of 35 to 49 kgf/ sq cm with a flow of 136 to 181 liter/ min.

Sanitation

• Food contact surfaces are subjected to sanitation after cleaning.• Sanitation plan involve the use of several physical and methods to reduce pathogenic and spoilage microbes to the acceptable microbiological standards.• Physical methods employs hot water steam mixed hot water UV radiations• Chemical sanitizers are more frequently used and includes Chlorine based sanitizers Iodophores Hydrogen peroxide

Characteristics Of Ideal Sanitizer

• It must be stable in presence of organic residues and hard water.• It should be non-corrosive and non-staining to the skin and surface.• It should not cause taint to food products.• It should be non-toxic.• It should be water soluble and easily rinsable.• It should be compatible with other chemicals.• It should be readily available in the market.

Criteria for Selection Of Sanitizers

Selection requires consideration regarding-• Microbial niche likely to be present• Amount of organic matter present on surface.• Anti microbial spectrum of sanitizers.• Volume, concentration and contact time required• Method of application • Safety aspect of the procedure for worker.• Economy and availability.

Factors Affecting The Efficiency Of Sanitizers

Various factors are-1.Concentration of sanitizers2.Temperature and duration of contact3.Acidity and alkalinity of the solution4.Presence of organic matter on the surface

Sanitizers Used In Meat and Dairy Processing Units

There are basically four types of sanitizers-1.Halogen based Sanitizers-Chlorine and Iodine is used as sanitizer.a.Chlorine- most widely used in the form of HOCl in aqueous solutionOxidizing effect is the basis of bacteriostatic action.More effective in low pH.Limitations-Corrosive to metal at high temperatureCertain resultant compounds are undesirable, like-Chlorophenol- cause taints at low concentrationOrganochlorine- health hazard and regarded as POP.

b. Iodophores-• Major Iodine compounds• Complex of elemental Iodine and surfactant• More stable in presence of organic compounds as

compared to Chlorine compounds.

Limitations- Less effective as sporocidal than Chlorine. Iodine may be lost at 50ºC due to sublimation. Costly, pH sensitive and have off flavours.

2. Quaternary Ammonium Compounds- Commonly known as Quats It is essentially bacteriostatic. Application- on floors, walls, furnishing and

equipments.

Advantages- Form stable film which confer continuous

bacteriostatic action. Non- corrosive to metal Good penetrability

Limitation- It is expensive

3. Amphoteric Compounds- Long chain substituted amino acids Compatible with all detergents Unaffected by hard water

4. Acid Sanitizers- It is frequently associated with cleaners Effective on stainless steel surface Mode of Application- CIP or spray or foaming Precautions- cleaners to be rinsed away as presence

of cationic surfactant will diminish efficacy.

Antimicrobial Spectrum Of Sanitizers

Sanitizer G+ G- Mycobacteria EndoSpores

Fungalspores

enveloped

Non- envelope

d

Prions

Chlorine ++ ++ + + + ++ ++ ±

Iodine ++ ++ + + + ++ + -

QAC ++ + - - + + - -

Acids ++ + - ± + + ± -

Alkalies ++ ++ + + + + ± ±

Aldehyde

++ ++ + ++ ++ ++ ++ -

Peracetic acid

++ ++ + ++ ++ ++ + -

Monitoring Of Cleaning And Sanitizing Efficacy

Cleaning and sanitizing efficacy of process is assessed by visual and microbiological examination. Visual examination is not very reliable but gives indication of cleanliness to some extent.For example- Sometimes soil is not easily seen if it is under film of water. Generally employed routine tests are microbiological culture methods like total viable counts and presence of indicator organisms. ATP bioluminescence method is rapid but it cannot differentiate the microbial ATP and ATP of other origin.

It utilizes luciferin and luciferase system to emit light in presence of ATP which is present in living cells. Now it is commercially available and provides results within 5 to 10 minutes onsite.

Thank you…..