Preface Dairy industry is an important segment of food industry in the country. The food business environment has under gone a sea change after the trade reforms initiated by WTO. Production of dairy products using good manufacturing practices is not sufficient until the product is made safe for the intended consumer. Food safety has been recognized as de rigueur for survival under competitive global market. The WTO agreement has made the World smaller for trading. Imported dairy and food products are flooding the Indian market resulting in stiffer competition for the local industry. India also needs to enter into World market with its own brands of dairy products and a beginning has been made by the Indian dairy industry in this direction. Although, India has achieved the status of largest milk producer, on quality front it lags behind considerably. If India has to make big stride in the export of dairy products to the other developed countries it becomes essential to harmonise with the existing standard procedures in the World trade. In the borderless world trade it has become imperative to signify the quality capability of a company by quality systems. In this direction it has become very essential to obtain necessary international recognition to exhibit our commitment to quality. To develop and manufacture globally competitive food product it becomes imperative to establish testing laboratories and centre for excellence for R&D. In order to manage production and quality of processed food, it is equally important to generate technically professional manpower through support to training institutions. The present monograph is an attempt to compile various chemical. Nutritional and micro-biological analytical techniques related to handling milk and milk products. The monograph has been divided into three basic sections dealing in methodologies applicable to raw milk reception to milk product analysis to air, water detergents and dairy effluent. Section “A” deals with various plateform and laboratory tests applied to raw and processed milk quality assessment, in terms of rapid tests, detection of adulterants and preservatives, sampling techniques etc. Section “B” gives the detailed analytical techniques as applied for determination of various quality parameters/ attributes of different dairy products being manufactured by Indian Dairy Industry. In section “C” various other tests applicable to dairy industry for maintaining quality including nutritional quality and hygiene, test for dairy detergents and sanitizers, air and water quality for a dairy plant and determination of malamine, aflatoxins, minerals and vitamins (fat & water soluble). Apart from coverage of various analytical techniques for maintaining quality of different dairy products, the text also contains various food regulatory acts, food safety act 2006, hygiene code, ISO 9000 series, ISO 14000 and ISO 22000 quality management systems, and BIS standards for different milk types and MRL values for pesticides, heavy metals and antibiotic substances and list of approved analytical labs are also provided for ready reference.

Milk is a product of biological origin and is a suitable vehicle to accommodate any additive without apparent changes in its look. The quality of milk and its products depends upon quality of raw milk used in their manufacture, processing and handling conditions. It is therefore, necessary to check quality of raw milk to assess its suitability for processing, through various quick tests called “Platform Tests” Raw milk quality assessment (A) At collection center: - Milk from various suppliers is generally collected at dairy factory or privately owned collection centers located in marked area of milk sheds. The quantum of supply may vary from 2 – 100 Liters. As each supplier has to be paid in relation to quantity and quality of his produce, it is important to draw samples and ascertain its quality by performing quick tests for the purpose of acceptance or rejection. Sampling procedures - The sampling procedure differs according to the nature of material and the purpose for which the sample is required. The sample collected for chemical analysis should be representative of the entire batch. Thorough mixing with proper instrument is essential to ensure representative sample. Samples for chemical analysis are to be delivered the same day for testing. If un-avoided, add small amount of preservative (Formaldehyde) to prevent deterioration and bear label to the effect. Sample from single container – The procedure involved is thorough mixing of contents. If it is small container the contents should be poured from one vessel to another with swirling. In case of can the contents should be mixed with the help of plunger which should be moved up and down and sideways for about 10-15 times. The sample is then drawn with the help of dipper from different levels and collected in clean and dry sample bottles.

Laboratory Tests Sampling procedures Samples from number of containers- As soon as the cans are received at the reception dock, remove the lid, mix contents of each can with a plunger and draw equal quantities from each container and mix together. Draw approximately 80 – 100 ml of sample for testing. If the cans are of same diameter, Alternatively, milk from different containers are first poured into a vat and then the sample is drawn by thorough mixing as above.. Samples from storage tank – Before drawing sample from storage tank, switch on the mechanical agitator and allow the contents to mix for 15-20 minutes. Discard first 1.0 L of milk. Transfer 250-500 ml of the mixed milk from the outlet valve into a sample bottle. Samples from rail / road tankers- Open the lid of the tanker and insert a big plunger through the main hole and move it forward, downward and backward bring the plunger to the surface at each stroke. Continue mixing for 15-20 minutes. Draw proportionate quantities of sample with the help of suitable dipper from different levels. Draw 250-500 ml of well-mixed sample into the sample bottle. The total volume of individual composite sample should not be less than 150 ml.

In the last decade or so, the problem of determining the microbial content and their activities in dairy products has been under close scrutiny. The dairy industries still adopt the dye reduction test because it is cheap, simple and satisfactory. However, other new techniques have been introduced along with some modifications in traditional tests. The microbiological quality must be maintained. To assess the bacterial content and their activities in dairy products, various methods are available for the microbiological testing of milk. The specific tests should be chosen as per the application and other factors like cost etc. On the basis of public health and economic consideration it is necessary to test microbiological quality of milk at a number of points along the chain from producer to consumer which includes - raw milk supply, bulk milk arriving at processors premises, monitoring bulk milk during storage prior to processing and monitoring the procession & the quality control of finished products. The techniques for estimating bacterial numbers in raw material are divided into two categories.

A. Estimation of Calcium Requirements : Pottasium permanganate solution (0.1N) – Dissolve by heating 33g of potassium permanganate in 1000ml distilled water and allow to stand in coloured bottle for several days. Filter contents through 6mm thick film of asbestos mat on Gooch crucible. Asbestos mat – Digest asbestos with dilute hydrochloric acid(1:3) for 2-3 days, wash free from acid and digest with 10% sodium hydroxide for few days, wash free from alkali. Digest with dilute Nitric acid(1:3) for several hours and wash. Shake with water into fine pulp and digest with 0.1N potassium permanganate solution that has been acidified with dilute sulphuric acid (1:3), for 1 hour and wash. Use this pulp for layering 6mm film on Gooch crucible. Dilute hydrochloric acid (1:4), Ammonium hydroxide solution (1:1), Saturated ammonium oxalate solution, Diluted sulphuric acid (1:4)

India has emerged as the largest producer of milk in the World. This has boosted the confidence of producers, planners, dairy entrepreneurs and scientist alike. India has poised to play a major role in global dairy market in coming decade. The rapid growth of science and technology has positive impact on our life style and with strong trend of urbanization several demographic changes are likely to occur. There going to be ever increasing demand on the role of milk and milk products for human health. Accordingly, the demand for higher standards of milk products in terms of hygiene and safety of dairy products is to be followed. The competitiveness for the export of milk products among different dairy industry has increased in recent times due to GATT agreement. The biggest challenge before Indian dairy industry is the quality and safety of milk products indented for human consumption. Legal standards are made to have control over quality of food offered for sale and to safe guard the consumer form health hazards. It is therefore, imperative to determine different parameters that define product quality and safety. The purpose is to ensure production and distribution of products within well defined and accepted standards. This chapter deals with various parameters of product testing in order to maintain requisite prescribed standards.

The growing chemicalization of milk presents a great challenge to the dairy industry. A number of chemical compounds get entry into milk, intentionally or un-intentionally, through their direct or indirect usage for crop, animal; or dairy husbandry practices, as environmental contamination. Several of these contaminants may be naturally present on grazing grass or use as pesticides for green fodder or they may get entry through use of compounded animal feeds. These eventually get excreted into milk as residues and pose problems to food safety. The risk of health hazards arises from veterinary drugs, residual pesticides, heavy metals, detergents and micotoxins etc. It is therefore, become necessary to detect these contaminants in order to make food safe for human consumption. Detection of Aflatoxin M 1 in Milk Material requirements : Glass column(30 cm x 1 cm), Silica gel (63-200 µg particle size), volumetric flasks, beakers, micro pipette, HPLC equipment fitted with C 18 column(25 cm x 4.6 mm) and fluorescence detector. Reagents: Sodium chloride solution (400g in 1000ml water), acetonitrile/water mixture (25:75), sodium sulphsate, chloroform, toluene/acetic acid mixture (9:1), acetonitrile/diethyle ether/hexane mixture (1:3:6), chloroform/acetone mixture (8:2), n-hexane and aflatoxin standard ampule. Preparation of stock solution : Transfer contents from 2.5ml or 0.5ml ampoule, quantitatively, to 25ml or 50ml volumetric flask respectively. Rinse ampoule with small quantities of chloroform and collect rinsing into flask. Makeup the volume with chloroform, mix well and store at 5º C or below. These solutions will contain 1 µg per ml aflatoxin M1. Working solution : Transfer 0.5ml of stock solution to a 10ml conical flask. Evaporate contents to dryness using inert gas. Dissolve residue in 10ml of acetonitrile/water mixture. Prepare series of dilutions containing 0.0025, 0.005, 0.01 and 0.025 µg/ml aflatoxin. Similarly treat 5ml of stock solution to give a concentration of 0.5 µg/ml.

Over the past several years, there has been significant change in consumer perception on quality and food safety. Consumers are demanding healthy, nutritious and cost-effective products processed under controlled hygienic conditions. Food safety concern, in recent years, has become dominant and important. The requirement of food safety and quality assurance has never been so demanding as it is now. Globally food safety is being addressed independent of food quality. In anticipation of consumer demands on food safety, food sanitary standards at national and international levels are under constant review. Several inter governmental agencies / organizations are engaged in work related to quality assurance and food safety. Amongst these World Health Organization (WHO) and Codex Alimentarius Commission (CAC) play the major role in protecting public health and defining standards of quality and safety aspects of foods for regional and or world wide usage. Regulatory Institutions The quality environment in the Indian food processing sector revolves around compulsory legislation which specify minimum standard and certification system. Legal standards are generally made to have control over the quality of foods offered for sale and to safeguard the consumer from health hazards posed by practice of adulteration. There are basically three types of Indian standards namely

Suggested Reading Arora, K.L. and Bhatia, K.L. (1990). Formal titration method for determining protein content in ice-cream. Indian Journal of Animal Sciences, 60 (10) 1252-1255. Arora.K.L. (1995) Determination of milk solids in flavoured milk using BIS lactometer. Indian J Dairy & Biosciences, 6 : 7-10. Bector,B.S., MotiRam and Singhal,O.P. (1998). Rapid platform test for detection/adulteration of added urea in milk. Indian Dairyman, 50(1), 59-62. Bishop,J.R., Senyk,G.F. and Duncun,S.E. (1993). Detection of antibiotic/drug residues inmilk and dairy products. In : Standard methods for examination of dairy products. 16thedition, American Public Health Assoc., New York. Brich,G.G. and Mwangelwa,O.M. (1974). Colorimetric determination of sucrose in sweetened condensed milk products. J Sci. Food and Agric., 25(11) : 1355-1362. CodexAlimentarious Committee, (1997). Recommended international code of practices. General principles of food hygiene. CAC/RCP -1 and 22. Fagel,A. and Ambrus,A. (2000). Recent development in field of validation methods. IDF Bulletin No. 351, pp 4-10. IDF Standard (1991). Milk and milk products. Recommended method for determination of organochlorine compounds (pesticides). IDF 75C pp 12 -15. IS: 1224 Part 1- Milk Part II, Milk Products (1977). Indian Standards. Determination of fat in milk by the Gerber Method IS: (First Revision). Bureau of Indian Standards, Manak Bhawan, New Delhi. IS: 1479 (Part-II) (1981). Indian Standards. Methods of tests for Dairy Industry. Chemical Analysis of Milk. Bureau of Indian Standards, Manak Bhawan, New Delhi. IS: 11964. (1987). Indian Standards. Method for detection of free acidity in casein. BIS, Manak Bhawan, New Delhi. IS (1992). Indian Standards. Specification for milk powder and skim milk powder. IS: 14433 (Part 1). (1997) Indian Standards. Specification for infant milk substitutes. BIS, Manak Bhawan, New Delhi. IS: 1656 (1997). Indian Standards. Specification for milk-cereal based weaning foods. (Third Revision). BIS, Manak Bhawan, New Delhi. IS: 2488 (Part1-Part5), (1998). Methods of Sampling and Test for Industrial Effluents. BIS, Manak Bhawan, New Delhi. IS: 2785 (1999). Indian Standards. Specification for natural cheese (Hard variety), Process cheese, Process cheese spread and soft cheese. Bureau of Indian Standards, Manak Bhawan, New Delhi. IS: 5887 (Part 3), (1999). Indian Standards. Methods for detection of bacteria responsible for food poisoning, General guideline on methods for detection of Salmonella (Second Revision). BIS, Manak Bhawan, New Delhi. IS: 5887 (Part 7), (1999). Indian Standards. Methods for detection of bacteria responsible for food poisoning, General guideline on methods for detection for detection of Shigella. BIS, Manak Bhawan, New Delhi. IS: 5401 (Part 1,) (2002). Indian Standards. Microbiology – General guidelines for the enumeration of coliform, (First Revision). BIS, Manak Bhawan, New Delhi. IS: 14988 (Part 2), (2002). Indian Standards. Microbiology of food and animal feed stuffs – Horizontal method for detection and enumeration of Listeria monocytogenes, BIS, Manak Bhawan, New Delhi. IS: 5887 (Part 8/Sec.1), (2002). Indian Standards. Methods for detection of bacteria responsible for food poisoning. Horizontal method for enumeration of coagulase positive Staphylococci (Staphylococcus aureus and other species). BIS, Manak Bhawan, New Delhi. IS 13334 (Part 1), (1992). Standard for skim milk powder (special grade). Indian standard Institution, manak Bhawan, new Delhi. IS :3508 (1966). Indian standards methods of sampling and tests for ghee. BIS, manak Bhawan, new Delhi. IS: 11202 (1984). Indian standards. Method for determination of lactic acid and lactate contest in milk powder and similar product, BIS, Manak Bhawan, New Delhi. ISI Handbook of Food Analysis Part 1 – General Methods IS:18 (Part 1) 1980. ISI Handbook of Food Analysis Part IX – Dairy Products IS: 18(Part IX) 1981. ISO (1975) Determination of lactic acid and Lactate content. ISO:3497(E). Joel F.Ross (1996) Total quality management. Vicinity Book International, New Delhi. Majonnier, T. and Troy, H.C. (1925). Technical Control of Dairy Products, 2nd edn. p 108. Majonnier Bros. & Co., Chicago, CF Laboratory Manual, 1959, 3rd edn. p 283, MIF Washington, D.C. Mannual for Dairy Chemistry (1982) ICAR -N.D.R.I., Publication. Mannual for Dairy Microbiology (1972) ICAR - N.D.R.I., Publication. Offical methods of analysis of the AOAC., (1984) 14th edition.,published byAOAC.,Virginia,USA. Official Methods of Analysis of AOAC International – 16th Edition – Vol. 1 and 2. Pub.- AOAC International, 2200 Wilson Blvd., Varginia, USA. Prevention of Food Adultration Act - as revised in 2006 Rao,G.S. and Arora,K.L. (1996) Colorimetric determination of sucrose in ice-cream. Indian J dairy sci., 49(4) : 293-298. Richmond, H.D. (1941). Richmonds Dairy Chemistry, J. G. Davis and F.J. MacDonald, 5th edn. p 160, Charles Griffen & Co., London. Singh,R.S., Chander,H. and Kaul,A. (1990) Detection of antibiotics in milk. Pub. No. 258, NDRI,Karnal. Sohrab, M. , (1997) – HACCP through ISO-9000 quality management system. Indian Food Industry, 16:3. Sohrab, M., (1999) – Risk assessment as pre-requsite for implementation of HACCP. Indian Food Packer, July-August. Standard Methods for Examination of Dairy Products. Ed. Robert T. Marshall, 16th Edition , 1993. Pub.- APHA, Washington D.C., USA. Sohrab, M. , (2000) – Adoption of Food safety management system-A challenge for dairy industry. Bev.Food World, 27:7. Standard Methods for examination of Water and Waste Water (1995), 19th Ed. APHA, Washington D.C. The Environmental (Protection) Act.,1986 (2000).Universal Law Publishing Co.Pvt.Ltd.,Delhi-110033 Wadhawa,B,K.; Bhattacararjee,S.K.; Bindal,M.P.; Chabra,A. and Mann,B. (2000) Standardization of package of practicees for analysis of organochloro pesticide residues in milk. Indian J dairy sci., 53(3) : : 169-176.