Condensed and Dried Milk
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CONDENSED AND DRIED MILK H. G. Patel Department of Dairy Technology AAU, Anand CONDENSED AND DRIED MILK CONDENSED AND DRIED MILK Author H. G. Patel Department of Dairy Technology AAU, Anand www.Agrimoon.com Page 1 CONDENSED AND DRIED MILK Index SN LESSON Page No 1. History, Status and Scope of Condensed Milks in India and 4-9 Abroad 2. Legal Standards for Evaporated and Condensed Milks 10-12 3. Grading and Quality of Raw Milk for Condensed Milks 13-17 4. Pretreatments for Concentrated Milks 18-24 5. Basics of Evaporators 25-28 6. Condensed Milk 29-31 7. Manufacture of Sweetened Condensed Milk 32-39 8. Manufacture of Sweetened Condensed Milk- Operations 40-45 9. Manufacture of Evaporated Milk 46-51 10. Pilot Sterilization and Heat Stabilization for Evaporated Milk 52-58 11. Recombined Concentrated Milks-Raw materials 59-62 12. Recombined Concentrated Milks-Processing 63-65 13. Physico-Chemical Changes during Manufacture of Condensed 66-69 Milk-I 14. Physico-Chemical Changes Taking Place during Manufacture of 70-74 Condensed Milk-II 15. Heat Stability Of Milk 75-85 16. Heat Stability of condensed Milk 86-94 17. Physico-Chemical Properties of Condensed Milk 95-97 18. Age Thickening and Gelation of Condensed Milk 98-100 19. Defects in Sweetened Condensed Milks 101-104 20. Defects in Evaporated Milks 105-107 21. Microbiology of Sweetened Condensed Milk 108-111 22. Microbiology of Evaporated Milk 112-113 23. Freeze Concentration 114-118 24. Membrane Concentration 119-122 25. Dried Milks: History and Status in India and Abroad 123-127 26. Grading and quality of raw milk for dried milks 128-132 27. Drum or Roller Drying 133-137 28. Freeze, Vacuum and Foam Drying 138-140 29. Spray Drying 141-145 30. Air Heating 146-148 31. Atomization 149-153 32. Separation of Air and Powder 154-157 33. Two-Stage Drying 158-161 34. Non Fat Dry Milk 162-166 www.Agrimoon.com Page 2 CONDENSED AND DRIED MILK 35. Dry Whole Milk 167-170 36. Technology of Dry Milks Resource 171-177 37. Factors Affecting Instantizing 178-183 38. The Milk Powder System 184-187 39. WPN Index and Heat Denaturation 188-191 40. Physical Properties of Dried Milks-I 192-202 41. Physical Properties of Dried Milks-II 203-212 42. Defects in Dried Milk during Manufacture and Storage, Their 213-220 Causes and Prevention-I 43. Defects in Dried Milk during Manufacture and Storage, Their 221-227 Causes and Prevention-II 44. Definition and Legal Standards for dried milks 228-236 45. Human milk and cow milk 237-243 46. HUMAN MILK SUBSTITUTES 244-253 47. Microbiological Quality of Various Dried Milks Including Infant 254-258 Foods 48. Management of Condensed and Dry Milk Industry 259-264 www.Agrimoon.com Page 3 CONDENSED AND DRIED MILK Module 1 History, Status and Scope of Condensed Milks in India and Abroad Lesson-1 1.1. INTRODUCTION Milk, skim milk, whey, and other milk products can be concentrated, i.e., part of the water can be removed. Its main purpose is to diminish the volume and to enhance the shelf life quality. Water can be removed from milk by evaporation and in addition to water, volatile substances, especially dissolved gases are also removed. Evaporation is usually done under reduced pressure — hence, decreased temperature — to prevent damage caused by heating. Water can also be removed by a membrane process called as reverse osmosis, i.e., high pressure is applied to a solution to pass its water through a suitable membrane. Water as well as part of some low-molar-mass substances passes through the membrane. A different method of concentrating is by freezing. Thus, condensed milk is cows‘ or buffaloes‘ milk from which a considerable portion of water has been removed. 1.2. HISTORY The evaporation of milk has been known for many years, even as early as in the year of 1200 when Marco Polo described the production of a paste like milk concentrate in Mongolia which was used by mixing with water. Then 600 years passed before we again find concentrated milk in the literature, but thereafter the development progressed rapidly. The advent of condensed milk belongs to 19th century. The condensed milk industry was introduced at about the same time as the factory system of butter and cheese making. Its rapid development stands in sharp contrast to the production of butter and cheese. Nicolas Appert condensed milk in France in 1820 and was developed afterwards in the United States in 1856 by Gail Borden, Jr. Before this development, milk could only be kept fresh for a short while and so was only available in the immediate vicinity of its production. After several attempts, Borden was able to produce a usable milk derivative that was long- lasting and needed no refrigeration. By 1858 Borden's milk, sold as Eagle Brand, had gained a reputation for purity, durability and economy. In 1864, Gail Borden's New York Condensed Milk Company constructed the New York Milk Condensery in Brewster, New York. This condensery was the largest and most advanced milk factory and was Borden's first commercially successful plant. The basic principle of the process of sterilization by heat was introduced by Mr. John B. Meyenbarg - a native of Switzerland in the year 1884-‗87. He conceived the idea of making condensed milk without the addition of cane sugar or other preservatives and without the necessity of keeping it cold. Mr. Meyenbarg experimented with the sterilization of condensed www.Agrimoon.com Page 4 CONDENSED AND DRIED MILK milk by steam under pressure and as the result of these experiments; he decided that it was possible to preserve milk without the aid of sugar by the use of revolving sterilizer which he designed. Originally the unsweetened sterilized condensed milk was sold under the trade name of Evaporated Cream. The Federal Food & Drug act of 1906 changed the name ―Evaporated Cream‖ to ―Evaporated Milk‖. The vacuum pan that was developed in 1883 has undergone marked improvement as a result of scientific knowledge and at present modern types of evaporators are available in different designs and shapes, which have much more advantages than the original one in terms of evaporating capacity, fuel efficiency and product quality. In 1911, Nestlé constructed the world's largest condensed milk plant in Dennington, Victoria, Australia. In 1914, Professor Otto F. Hunziker, head of Purdue University's dairy department, published a book titled Condensed milk and milk powder. This text, along with additional work of Professor Hunziker and others involved with the American Dairy Science Association, standardized and improved condensery operations in the U.S. and other countries. 1.3. DEVELOPMENT OF CONDENSING PROCESS The simplest evaporator is an ordinary open pan heated with steam or direct gas. The evaporation takes place from the surface while the liquid to be evaporated is heated up to the boiling point corresponding to the ambient pressure, which at sea level will be 100°C. As the evaporation has to take place from the surface, which is limited in relation to the content of the pan, the evaporation will naturally take long time. The milk will be exposed to the high temperature with deterioration of the proteins and chemical reactions such as the Maillard reaction or even coagulation results. As the development went on, the concentration was carried out in forced recirculation evaporators and multi stage evaporators. For the separation of liquid and vapours, centrifugal separators are preferred. There are principally two kinds of condensed milk namely Sweetened Condensed and Unsweetened Condensed milks. Both reach the market in hermetically sealed tin cans. Sweetened Condensed Milk as the name suggests is sweetened with addition of sugar which acts to enhance its shelf life. Unsweetened condensed milk is known by trade name ―Evaporated Milk‖. It is made by removal or evaporation of water from milk without the addition of any preserving material. The canned product is heat sterilized to extend shelf life. Fortification with vitamins of either or both A or D3 is common. Because of its concentrated form, evaporated milk is a multipurpose, convenient dairy product ready for every milk use. Evaporated skim milk is obtained by a simple concentration of skim milk by vacuum evaporation or reverse osmosis. Evaporated filled milk is a prepared blend of skim milk, vegetable oil, stabilizers and vitamins. www.Agrimoon.com Page 5 CONDENSED AND DRIED MILK The improvements in modern equipment are: a. Change of metal from copper to stainless steel. b. Double and triple effect or combination of single effect evaporator with thermo- temperature control. c. Plate type evaporators were developed in 1958. 1.4.4. USES OF CONDENSED MILKS The common uses of concentrated / condensed milks in different parts of the world are shown in Table 1.1 as under: www.Agrimoon.com Page 6 CONDENSED AND DRIED MILK 1.5. STATUS OF CONDENSED AND DRIED MILK INDUSTRY IN INDIA AND ABROAD 1.5.1. Status in India Milk production in India is 116.4 million tones in 2010-11. Around 135 Dairy Plants both in private and public sector in India are producing or dealing with concentrated and dried milks of various kinds. The milk utilization pattern and its related statistics is given in Table-1.2 below. www.Agrimoon.com Page 7 CONDENSED AND DRIED MILK www.Agrimoon.com Page 8 CONDENSED AND DRIED MILK 1.5.1. Condensed milk The market for condensed milk is small and has been growing at a slow pace. The production of condensed milk has increased with an average annual compound growth rate of ~ 4 % during1991 & 2001 period.