Milk Testing Equipments

We have discussed the general purpose instruments used in chemical and microbiological laboratories and also the instruments used to determine the physical and rheological properties of food and other substances. Sophisticated modern equipments/ instruments which can determine very low concentration of constituents with great precision like rancimate, GLC, TLC, HPLC, GCMS and LCMS have also been discussed. However, these instruments are of general use and can be used in any laboratory for example in pharmaceutical, forensic laboratory, food laboratory etc. On the other hand, there are some instruments which are specifically designed to be used in a dairy laboratory to determine the physico-chemical properties of milk and milk products. Some of these instruments are discussed below.

i. Gerber Centrifuge: Gerber centrifuge is used for the determination of fat in milk and milk products. This centrifuge is different from other centrifuge. It has provision to hold special glass tubes known as butyrometers, time adjustment clock and rotate at fixed speeds.

ii. Lactometer: Lactometer is a special type of hydrometer used for the determination of specific gravity of milk and to calculate the total solids and solid not fat (SNF) in milk. There are different types of lactometers such as zeal lactometer, Quevene type of lactometer and ISI lactometer etc. Lactometer consist a slender glas stem of uniform diameter connected to a large glass chamber, this chamber causes the instrument to float. At the lower end of the body is a glass bulb filled with lead shots or mercury which enable the instrument to sink to a proper level and also to float. Depending upon the specific gravity of milk the extent of sinking of the lactometer gives an idea of the purity of milk.

iii. Milko Tester: There are 3 models mark II, mark III and automatic. The instrument is used for fat determination in milk. It can analyse 80-120 samples/ hour and require very small sample of milk (1.6 ml). The instrument gives results which are comparable to reference method. The instrument determine the fat content on the basis of scattering of light by a diluted sample of milk. Calcium chelating agent eliminate the turbidity caused by the casein micelles, hence the scattering of light is due to the presence of fat globules. The size and number of fat globules influence the result therefore the sample is homogenized in a 4-stage homogenizer to reduce the size of the globules to a specific size.

iv. Electronic Milk Tester with Digital Read out: This instrument is manufactured in the country by the Rajasthan Electronic and instrument Ltd Jaipur. This is a electronic instrument used for determination of fat content of milk.The determination follows the well known principle of dilution, mixing,homogenization and photometric measurement of light scattered by the fat globules present in milk sample. Fat content is displayed quickly and accurately on a digital readout.

v. Infra Red Milk Analyzer (Milko Scan) Lactoscope: This instrument is used for simultaneous determination of Fat, Protein, solid not fat (SNF) and lactose in milk. The infrared milk analyzer measures absorption of infrared energy by carbonyl groups at 5.7 in the easter linkage of fat molecules, by peptides (at 6.46) linkages of amino acids in protein molecules, and by hydroxyl groups of lactose molecules (9.6). The SNF is determined by putting a constant to instrument values for protein and lactose. In 1975, Foss Electric co. intdouced the single cell, dual wavelength infrared milk analyzers (milko scan 203 and 300). In these instruments optical filters isolate the specific wave lengths absorbed by fat, protein and lactose and reference wave lengths not absorbed by these components, thus eliminating the need for a diffraction grating. The 100 series milko scan are the improved version of earlier milk scan. In this series milko scan 133-B is the latest micro processor controlled instrument.

vi. Lacto star Automatic Milk Analyzer: Lactostar-9 new, versatile, esy to operate, microprocessor based, fully automatic milk analyzer determines fat,SNF, proteins, lactose and freezing point of milk. The instrument is introduced in India by Funke Gerber, Germany. It applies a combined thermo-optical method to analyze the milk constituents. It determine the sum of fat and proteins by optical measurement (Turbidemetric), while fat and SNF content are determined by thermal analysis, whereas the lactose and proteins are determined by computationed analysis. The freezing point is predicted on the basis of protein and SNF content.

vii. Lactoscope: Lactoscope from Delta instrument determines fat, proteins,lactose, SNF and total solids in milk and milk products. The instrument is very sophisticated and built for self-service so that any maintenance that is required can be carried out via a modem connected to the manufacture’s head office.

Modern/ Sophisticated Instruments

Instrument discussed above are general purpose instruments which provide useful information regarding physicochemical properties and microbiological analysis of milk and milk products (proximate analysis). However, development of more sophisticated instruments has enabled the estimation of pesticide residues, toxins, antibiotic residues etc in part per billion (ppb) levels which was impossible with classical instruments. Some of these instruments are discussed below in brief.

i. Flame Photometer: Flame photometer is used for the quantative chemical analysis for the determination of alkali and alkaline earth metals (Sodium and Potassium etc.) present in solution. Flame photometer is must when concentration of the element is very low, say of the order of 1ppm as ordinary method, such as gravimetric or volumetric will not respond. The principle of flame photometer is based on the fact that different eliments emits light of different wave length on burning in a flame. This characteristics wave length by a particular element isolated to the characteristics wave band by an optical filter is allowed to fall on a photocell whose output is measured by a suitable deflection for instant an electronic amplifier and a meter or glavnometer. The intensity of the emitted light is proportional to the concentration of the element in the solution. Thus the concentration of an eliment can be determined in the solution through determination of the intensities of solutions of different but known concentrations and preparation of a standard curve.

ii. Atomic Absorption Spectrophotometer: This instrument employ special light source (hollow cathode lamps) constructed for the specific element to be analyzed. A sample is dissolved in a solvent and burnt for atomization and light from the specific cathode lamp is passed through the flame. The proportion of light absorbed is proportional to the concentration of the element in the sample.

Thus by comparison of the extent of absorbed light of the unknown sample and a series of standard solutions it is possible to calculate the concentration of the element in the unknown sample. The instrument is widely used and accepted technique for determining trace (hg/ml) or ultra trace (sub-hg/ml) levels of an element in a wide variety of samples.

iii. High Precision Thin Tayer Chromatography (HPTLC): In chromatography the solution are resolved by differential rates of elution as they passes through the plate or column. Their separation is governed by their distribution between the stationary and mobile phases. HPTLC is a more sensitive, adaptable and rapid technique than paper chromatography. It has wide application in quantifying as well as qualitative analysis of various biomolecular. It is the cheapest and the best method for isolating and identifying minor components of food.

iv. Gas Liquid Chromatography (GLC): It is the most elegant and useful method in analytical chemistry. It is a form of partition chromatography in which the stationary phase is a film held in place on a solid support and the mobile phase is a carrier gas flowing over the surface of a liquid film in a controlled fashion. The vaporized sample is fractionated as a consequences of being partioned between the mobil gas phase and liquid stationary phased held in a column. Analysis of food using GLC is concerned with the assay of lipid, proteins, carbohydrates, preservatives, flavours, colorants and texture modifiers. It is particularly suitable for determination of fatty acid profile of the food lipids and flavours compounds of a food. It is also usefull in the analysis

of vitamins, steroids drugs and pesticide residues.

v. High Pressure liquid chromatography (HPLC): This is a very fine and high precision technique but the successful use of the techniques for a given problem requires the right combination of a variety of operating conditions such as the type of column, packing and mobile phase, column length and diameter, flow rate, column temperature and sample size. In fact newer columns and packing materials offer high performance at moderate pressure (although still high relative to gravity flow). HPCL methods have been developed in a variety of areas including organics, biological, small molecules, macromolecules, pollutants, polymers, and many others. Chromatography can be done in a number of modes. The best mode for a particular separations depends on the structural characteristics of the solutes to be separated and the analysis requirements. HPLC methods can be selected based on the molecular weight and the solubility of the substance. In many samples separation can be achieved by reverse phase chromatography using a bonded silica, stationary phase.Reverse phase HPLC is the first choice because it is often faster, cheaper and easier than other alternatives.

vi. Rancimate: This is a modern, PC-controlled instrument which is used to determine the oxidative stability of a fatty food. The determination of the oxidative stability in natural fat and oils is a method of quality control in food industry. This method has been developed as an automated version of the extremely demanding AOM method (active oxygen method) for the determination of the induction time of fats and oils. In this method the highly volatile organic acids produced by oxidation are absorbed in water and used to indicate the induction time.

vii. Liquid Chromatography Mass Spectrophotometer (LCMS): Its an indispensable tool for problems solving in virtually all analytical fields requiring “information rich” chemical analysis. Its use is must when the concentration of residues and contaminants is in PPB levels.

viii.Gas Chromatography Mass Spectrophotometer (GCMS): It involves high resolution capillary gas chromatography with mass spectral detection,aids in the analysis of residual volatiles in polymers, pharmaceuticals and packing materials. It is must for the pesticide analysis.

Microbiological Instruments/ Equipments

i. Freeze Drier: Freeze drier is used for the preservation of different biological products such as starter culture, antiobiotics etc. without damaging their cell structure. The principle of freeze drying consists of the removal of the ice contained in frozen product by sublimation.

ii. BOD Incubator: This is generally used to incubate the biological samples for optimum microbial growth. The temperature range of the incubator may be from 50 C to 500 C or higher. Refrigeration in the instrument is done by cooling coils and heating by air heaters.

iii. Bacterial Colony Counter: It is used for counting the colonies directly in a petri plate. A fluorescent light is provided for the uniform light illumination.

iv. Autoclave: It is used for autoclaving culture media and also for sterilization of glass equipments. It is equipped with water level indicator, pressure gauge, timer,digital thermometer and automatic temperature recording system.

v. Microscope: It is used to determine the bacterial population of a sample of milk and milk products. It is also useful in providing information about the type of contamination in milk and milk products.

vi. Biosafety Cabnets: It prevent the cross contamination of biologicals and protect the worker from exposure within the work zone. It has a true laminar airflow.Horizontal laminar airflow is specially designed to provide the particle free bacteria free, clean air environment needed for laboratory testing, manufacturing, inspection etc. under microbial free environment.

Instruments for Physical/ Rheological Properties

These instruments can be used to determine the physical/ rheological properties of milk and milk products although these are the general-purpose instruments.Physical properties like viscosity, surface tension, melting point and freezing point electrical conductance; heat capacity refractive Index etc. are some of the important physical properties which are used to determine the richness or purity of milk and milk products. Whearess springiness, gumminess, cohesiveness etc are the rheological properties, which are determined to judge the texture profile of different dairy products. The important instrument used to determine the physical/ rheological properties of milk and milk products are discussed below.

i. Viscometer: This instrument is used to measure the viscosity/ consistency of milk and milk products. Number of instrument are available in the market for this purpose. Ostwald viscometer is generally used to measure the viscosity of fluid milk while the hoppeler or some other viscometers are used to determine the viscosity of semi liquid products like condensed milk, ice-cream mix etc.

ii. Refrectometer: This instrument is used for both qualitative and quantative analysis such as identification of oils and fats, concentration of sugar solutions and determination of total solids of products (condensed milk etc). There are number of instrument used to determine the refractor index of the solution. In the dairy industry the refrectometer is used to determine the desired concentration of total solids during the manufacturing of sweetened condensed milk and to determine the purity of ghee using a special refrectometer (butyro-refrectometer).

iii. Polarimeter: The polarimeter is used to determine the concentration of those substances in solution which are optically active and are capable to rotate the plane of polarized light examples are amino acids, sugars, steroids, terpenes etc. As the extent to which the plane of polarized light is rotated by an optically active compound is dependent on the concentration of its solution the instrument can be used to determine the concentration of these substances. Whereas the direction (levo or dextro) of rotation is used to identify the optically active substance.

iv. Cryscope/ Cryostar: It is used for the determination of freezing point of liquids such as milk and can reveal the purity of the liquid as the addition or removal of any substance in it can lead to a change in its freezing point.

v. Instron: It is a very sophisticated instrument which is used to determine the rheological properties like springiness, guminess co-hesivoness etc. This instrument is very useful in judging the texture profile of butter, shrikhand, khoa, panee,r, chhana and cheese etc.

General Purpose Equipments/ Instruments

These equipments/ instruments are general purpose and are required in any chemical laboratory. A brief description of there instruments is given below:

i. Water Bath: It is used for heating purposes for samples of milk and milk products and certain other heating operations. It should have a digital temperature display, temperature range from 10o C to 100o or higher and stainless steel interior heating with an overheating protection. Operation of the bath must be with distilled water.

ii. Analytical Balance: The analytical balance is the most important instrument in any chemical laboratory and is used to weigh the sample as well as the analytical reagents. The modern instruments are equipped with piece counting and percentage determination devices and formulation memory. Maximum capacity of the balance may be upto 200g weight and the minimum weight which can be determined must be 1/10 h of mg.

iii. Drying/ heating oven: Oven is used for drying glassware and heating the samples, particularly in the determination of moisture and fat percentage in milk and milk products. The temperature range may be from 10o C to 150o C or higher. It should be thermo statistically controlled and equipped with air circulating fan.

iv. Muffle Furnace: Muffle furnace is used for ashing the sample of milk and milk products in the determination of salt constituents like calcium, magnesium, sodium, potassium, chloride, phosphorous etc. Muffle furnace must have maximum temperature up to 1000o C or 1200o C and must be equipped with a pyrometer.

v. Magnetic Stirrer: Magnetic stirrer or laboratory stirrer is used for shaking or mixing the sample. It can also be equipped with a hot plate.

vi. pH Metter: It is used for the determination of pH and oxidation-reduction potential of samples or other substances like buffers and other reagent solutions.It must have the ability for automatic temperature compensation, recorder connection and calibrated data memory. This instrument measure the potential difference between a glass electrodes and a standard calomel electrodes and is calibrated with buffers of known pH. Temperature compensation devices are incorporated to correct for temperature deviations. Liquid and semisolid foods can be examined for their pH but solid food is used only after making slurry with water.

vii. Kjeldahal digestion and distillation apparatus: It is used for the determination of nitrogen content in a food products. The protein content of the product is then calculated by multiplying the nitrogen content with a factor which is derived on the basis of percentage of nitrogen in the proteins of a particular food. For milk and milk product this factor is 6.38 as milk proteins contain about 15.65% nitrogen in them. The original instrument consists of aluminum frame in which digestion cum distillation flask is fitted alongwith a glass tube and metallic (silver) tube and glass condenser which convert the ammonia gas into liquid ammonia to be collected in a conical flask containing standard solution of acid. Now a days more sophisticated and automatic instruments are available for the determination of proteins by kjeldahal method.

viii. Infrared moisture balance: The improved moisture balance is used for determination of moisture content of food products without changing their chemical structure while loosing water under exposure to infrared radiation.The instrument is very handy and portable with sensitive torsion balance calibrated in moisture percentage.

ix. Karl Fisher Titration Apparatus: It is widely used titrimetric method for moisture determination in food products. The equipment is available with a choice of titrators, coulmeters, stand and accessories as well as reagents for titration. The equipment can be connected to a PC equipped with software for an accurate automatic system that meets all needs for moisture determination.

Laboratory Equipments and Instruments

India being the highest milk producer in the world and its higher growth rate compared to many of the developed nations is poised to play a major role in the global dairy market. The changing dimensions in food processing industry call for adopting good manufacturing practices. Consequent to enforcement of food safety and standards Act 2006 and sanitory and phyto-sanitory measures, under the World Trade Order (WTO) agreement the dairy sector have to put in place strict quality control mechanism ensuring international quality standards and hygienic conditions. For this purpose we need analytical instruments which are simple to operate and very sensitive in determining the traces of contaminants. Such as pesticide residues, antibiotic residues and toxins in parts per billion (ppb) levels.The present unit give introductory outlines to some of the equipment and instruments which can be used for proximate analysis, determining physical/ rheological

properties of milk and milk products, may be used in microbiological analysis and some of the very precision instruments like LCMS and GCMS etc which enable the determination of traces of the contaminants and toxicants. Some of the instruments designed to be used for milk and milk products are also discussed.

Hazard Analysis Critical Control Points (HACCP)

HACCP is a science based systematic approach to food safety to provide safe food to customers.

Depending on the product and the processes involved the CCPS differ.

The system requires top management commitment and a dedicated team to plan and implement.

Some preliminary steps required to implement the HACCP principles in the Food Industry are discussed below:

1. Assembling HACCP Team – HACCP Team is a multi skilled Team consisting of Specialist from different fields like microbiologist, chemist, technologists, engineer, product specialist for developing an effective HACCP Plan.

2. Description of the product. – Product has to be described completely. The team should have a complete knowledge of the product.

3. Identifying intended use – Use of the product has to be understood properly –Where how and who will be using the product.

4. Construction of flow diagram – All the stages in the food chain from reception of raw materials, processing, storage and all other operations have to be properly put stepwise on a sheet of a paper.

5. On site confirmation of the flow diagram – HACCP Team shall visit the place where each step of the process is being carried out and confirm the Flow Diagram.

Apart from the above five points GMP and GHP form the foundation for the above preliminary requirements.

Having carried out the preliminary steps let us understand seven HACCP principles.

1. Hazard analysis.

2. Determine the Critical Control Points (CCPs)

3. Establish critical limit (s).

4. Monitor the CCP.

5. Establish the corrective actions.

6. Procedure for verification

7. Documentation.

Principle 1 – Hazard Analysis.

•  Hazard is nothing but an agent in food, which can cause an adverse health effect.
•  Primarily, there are three basic food hazards, namely biological, physical and chemical.
•  Relative risk of each hazard is assessed based on the probability of occurrence and its effect on the human health.
•  In Milk, the biological hazards are bacteria / germs, virus, fungus etc which enter into the milk from the animal, environment, improperly cleaned equipments or if the milk is not stored properly (At refrigerated temperature)
•  Physical hazards in milk could be dust / dirt, grass, hair or other foreign matter which finds its way in to the milk at village level.
•  Contaminated water, soap / detergent solution used for cleaning of equipments, other natural contaminants or milk is adulterated intentionally constitutes the chemical hazards.
•  This exercise is repeated at different steps in the process.

 Principle 2 – Determine the critical control points (CCPs)

•  Having done a preliminary hazard analysis, the next step is to identify critical control points with the help of a series of intelligent questions.
•  Critical Control Points is defined as a point where control is necessary for food safety.
•  All significant hazards identified during hazard analysis are addressed
•  In Mother Dairy, two Critical Control Points have been identified.
•  One is pasteurization of milk and second is storage of milk (Pasteurization is a process where the milk is heated to a defined temperature and held at that temperature for a defined time and immediately cooled to less than 10°C. Heating is done to destroy all the pathogens, i.e. disease producing micro organisms and most of the non-pathogenic but milk spoiling organisms to make milk safe for human consumption. Cooling is done to stop the growth of the remaining harmless
• bacteria.

 Principle 3 – Establish critical limit (s).

•  Once the critical control points are established , limits for preventive measures are determined associated with each identified CCP.
•  Critical limit is the point, which differentiate between safe and unsafe products.For each CCP, a critical limit is defined. Critical limit should be meaningful and realistic.
•  At Mother Dairy, HTST (High Temperature Short Time) Pasteurizers is used for pasteurizing the milk. Pasteurization temperature (77 ± 2°C) and time (15 seconds) are specified. For storage of milk, we specify storage temperature(less than 7°C).

 Principle 4 – Monitor the CCP.

• Monitoring is a planned sequence of observation or measurement to assess whether a CCP is under control.
•  Rapid Physical and Chemical tests are carried out on the spot and the lengthy microbiological tests are carried out later .
•  Action plan is made to monitor CCPs. It is specified in the plan what to monitor,how to monitor, who will monitor and when to is monitor.
•  At Mother Dairy the time and temperature is monitored on Distributed Control System (DCS) continuously. Temperature is set at 77 ± 2°C and is controlled by PID (Proportionally Integrated Derivative) on steam valve and diversion is set at 75°C.

 Principle 5 – Establish the corrective actions.

•  If the critical limit is violated, then corrective action is instituted.
•  Corrective actions are written procedures to be followed when a deviation occurs.
•  The actions must ensure that the CCP has been brought under control.
•  Corrective actions taken must be recorded.
•  In case of milk processing, the critical control point was milk pasteurization temperature. If temperature drops less than 75°C, milk is automatically diverted to balance tank for reprocessing.
•  The confirmatory test for pasteurization is phosphates test. If this test is found positive the milk is reprocessed
•  For the storage of milk, critical control point was the storage temperature. If the temperature during storage is found more than 7°C, which is the specified limit, the milk is further deep chilled using Glycol System during filling into tankers.

 Principle 6 – Procedure for verification

•  Verification is a confirmation process that HACCP Plan is effectively and accurately implemented.
•  Verification activity includes What, How, When and Who.
•  Each batch of pasteurized milk is tested for phosphatase test before it is released for filling into tankers for dispatch. Only batches passing the test are taken for filling.
•  Frequency of verification at Mother Dairy is once a month to conform that the HACCP system is working effectively.
•  Verification is also done by HACCP Certifying Agency once a year.

 Principle 7 – Documentation

•  Efficient and accurate record keeping is essential to the application of HACCP system.
•  HACCP procedures should be documented i.e. Hazard Analysis, CCP determination, critical limit etc.
•  It includes all related processing records, monitoring records and corrective action records, HACCP check list etc.
•  All the records related to HACCP in Mother Dairy are stored in Computer.

 For the benefit of the readers, various steps involved in HACCP systems and the questions to be asked at each step of the operations to determine CCPs are given below

DETERMINATION OF CRITICAL CONTROL POINTS

Training

All employees handling milk and milk products should be aware of their role and responsibility in protecting food from contamination and deterioration. They should have the necessary knowledge and skills to enable them to handle food hygienically.They also should know the nature of food items and the conditions under which the products to be handled to make them free from contamination and deterioration.

Product Information and Consumer Awareness

Product information, including storage and usage should be properly put on the label or informed to consumers by suitable means through posters, advertisements,meetings or gatherings. Consumers should also be appraised of hygienic practices followed in the establishments to produce and distribute safe food label declaration should meet all the statutory requirements besides giving more information to the consumers on the product.

Transportation

Where necessary conveyances and bulk containers should be designed and constructed so that they

•  Do not contaminate milk or packaging.
•  Can be effectively cleaned and where necessary disinfected.
•  Permit effective separation of different milk and milk products from non fooditems where necessary during transport.
•  Provide effective protection from contamination including dust and fumes.
•  Can effectively maintain the temperature, humidity, atmosphere and other conditions necessary to protect milk from harmful or undesirable microbial growth and deterioration likely to render it unsuitable for consumption.
•  Allow any necessary temperature, humidity and other conditions to be checked.

 For proper use and maintenance of transport:

•  The conveyance should be in proper condition.
•  It should be clean.
•  It should carry the goods specified
•  Wherever disinfection is required before loading or after loading should be carried out.

Personal Hygiene

•  Health Status: Employees should report illness or symptoms of illness. Those with infectious diseases or illness likely to be transmitted should not be allowed to enter in milk handling areas.
•  Periodical examination of health status of employees should be carried out,documented and appropriate action taken.
•  Personal Cleanliness & Behaviour: Regular bath, nails trimmed, hair combed,beard or long hair bandaged in nets, no jewellery, no smoking, no chewing paan or tobacco, no sneezing or coughing over unprotected food, no watches have to be practised in food handling areas.

Management and Supervision

•  Managers and Supervisors should have sufficient knowledge on milk hygiene principles and practices and be able to take suitable protective and preventive actions.
•  Documentation and Records enhance the credibility of the food safety system.Records for various processess, production and distribution should be kept exceeding the shelf life of the product.
•  Recall procedures should be in place for traceability of the product. Effective recall of the defective products should be in place and their disposal should be properly documented.
•  For effective monitoring periodic inspection should be carried out and wherever required appropriate changes have to be made.

Control of Operation

 Food Hazards are controlled by adopting HACCP System.

 Key aspects of Hygiene Control Systems include time temperature combination and prevention of microbial contamination.

Time and temperature control

Time temperature combination should be such that

•  The properties of milk is altered minimum or as desired
•  Intended shelf life of the product is achieved
•  Microbial population is reduced or totally eliminated as applicable to the process
•  Measurement of temperature and time should be carried as demanded by the process.

 Microbiological Cross Contamination : It is prevented by adopting the following steps.

•  Raw unprocessed milk should be separated from final/ready to drink milk
•  Access to processing areas may be restricted or controlled
•  Access to process areas should be through changing facility. Personnel to put required clothing, wash hands, change footwear before entering process areas

 All equipments and surfaces coming into contact with milk material should be cleaned thoroughly after use. Wherever required they have to be sanitized or sterilized.

Physical and Chemical Contamination

•  Systems like HACCP prevent contamination of milk with metal, glass pieces,torn clothes or gloves, harmful fumes, dust and unwanted chemicals. More details on HACCP are explained in this book in later pages.

 Incoming Material Requirements

Raw material should be checked before accepting and storing. Only material meeting the company standards should be accepted.

Packaging

Packaging design and materials should provide adequate protection for products to minimize contamination, prevent damage and accommodate proper labelling.Packaging materials or gases where used must be non-toxic and not pose a threat to the safety and suitability of milk under the specified conditions of storage and use.

Where appropriate, reusable packaging should be suitably durable, easy to clean and where necessary, disinfection to be carried out.

Water

In contact with food

•  Only potable water should be used except in steam production, chilling and cleaning operations. Recirculated water and water recovered from processing of milk by evaporation or drying may be used after testing to confirm it is safe and suitable for the drinking.

 As an ingredient :

•  To avoid contamination only potable water should be used.

 Quality Ice and Steam : 

• Water used in producing steam or ice should not cause any food safety problem when it is in direct contact with milk or milk contact surfaces.

Selection, Design, Structure and Facilities

Area Selection :

•  Pollution free area
•  Activities nearby should not contaminate food
•  Area free from infestation & pests
•  Should not be low lying area
• Waste collected during milk handling should be able to dispose off easily.

 Design & layout :

Design & layout should permit practice of good hygienic practices and prevent cross contamination during handling of milk.

Internal structures and fittings :

•  Structure should be built with durable materials
•  Walls, partitions and floors should be free from cracks and crevices
•  Slope on the floor should be constructed for proper drainage and cleaning
•  Ceiling and overhead fixtures should be constructed and finished to minimize the build up of dirt and condensation and the shedding of particles.
•  Windows should be easy to clean
• Use insect proof screen wherever necessary
•  Doors should have smooth and non-absorbent surfaces. They should be easily cleanable
•  Working surfaces coming into direct contact with milk should be sound, smooth,inert to milk and cleanable.

 Quality Equipment :

•  Location of equipment should be easy to handle, clean and maintain.
• Design of equipment should not create problems in following hygienic practices.
•  General equipments and containers should be made of materials with no toxic effect for the intended use. Where necessary they should be durable, movable or capable of being dissembled to allow for maintenance, cleaning, disinfection and monitoring. The design should be convenient for cleaning inspection, for pests or milk particles.
•  Food Control and Monitoring Equipments
•  Material and design of equipments should be such as to withstand process like cooking, heating, chilling, freezing and storing.
•  Should be able to fit monitoring equipments like temperature and pressure gauges on the equipments.
•  Containers for waste, non-edible, reject materials
•  Containers are properly labelled and installed or placed at appropriate places
•  Proper construction can be made wherever necessary
•  Locking arrangement to prevent moisture or reject/non-edible products should be there.

 Facilities :

Water supply

•  Potable water should be available for drinking and cleaning equipments
•  Clean water for floor washing and other non-drinking purpose.

 Drainage and waste disposal

•  Waste should be removed and disposed from the area of milk handling. Waste water should be treated before disposal. Waste stores must be kept appropriately clean.
•  Adequate drainage and waste disposal systems and facilities should be provided.

 Cleaning

•  Adequate facilities, suitably designed, should be provided for cleaning milk,appropriately utensils and equipment. Such facilities should have an adequate supply of hot and cold potable water where ware appropriate.
•  Cleaning and disinfection programmes should ensure that all parts of establishment and equipment are clean.
•  Cleaning programmes and the responsibilities are specified.

 Pest Control System:

 Building, walls, floor should be free from cracks and crevices. Drain holes should be covered with mesh or traps to prevent the entry of pests. Regular inspection for breeding or infestation of pests should be carried out and if observed immediate corrective action should be taken. Treatment with chemical, physical or biological agents should be carried out without posing a threat to the safety or suitability of milk.

Primary Production

 Healthy milch animal:

 -The animal should be healthy. Proper veterinary care should be given. Proper care should be taken to ensure that the veterinary drug residue should not exceed the limits prescribed under law. Feed should be nutritious and as per requirement.

 Clean environment, covered and ventilated shed for the animals:

- The animal should be housed properly to avoid contamination/ infection.

Potable water:

- The water should be clean and should not be a source of contamination/ infection.

 Quality feed:

- The feed should be as per the season and need. It should contain all the components in proper ratios. It should not be source of aflatoxins.

Proper dung & urine disposal system:

- The system should be adequate enough to prevent breeding of flies and insects. Also the dung can be properly utilized for Gobar Gas production/ manure. The disposal system should be sufficiently away from the place where the animals are kept.

 Clean equipment to handle milk:

- The equipment should be preferably of stainless steel material. After use these should be cleaned, sterilized/sanitized and kept safely to avoid contamination before use.

 Healthy milk handler:

- The handler should be healthy and free from any infectious diseases. Also he/she should have clean habits such as no smoking, no chewing of pan/ tobacco and wear clean clothes. During milking the handler should ensure that nails are properly cut, hands are properly washed, hair are properly combed and covered.

Steps to be followed during milking:

•  Washing hands before milking
•  Cleaning udder before milking
•  Using clean and sanitized equipment
• Discarding first few drops of milk
•  After milking cleaning the udder with water and disinfectants
•  Closing the vessel containing milk
•  Carrying milk to the Society fast.
• Chilling the milk at the centre or sending it to the Dairy Plant as quick as possible.
•  Keeping the milch animals/milk handling area clean to prevent breeding of flies,mosquitoes & other pests.
•  Dairy should provide proper (covered) transportation, clean & sterile cans to all the collection centres.