Condensed milk presentation .....Definition ; Composition and Standards ; Food and Nutritive Value of Condensed and Evaporaled Milks; Physico-chemical Properties ; Role of Milk Constituents in Condensed Milks ; Method of Manufacture, Packaging and Storage

all about condensed milk

1. Condensed Milk By Aaryan Keshri & Akash Bijay

2. Index Introduction and Development Definition Composition and Standards Food and Nutritive Value of Condensed and Evaporated Milks Physico-chemical Properties Role of Milk Constituents in Condensed Milks Method of Manufacture, Packaging and Storage of Condensed Milk Method of Manufacture and Storage of Evaporated Milk Method of Manufacture and Storage of Evaporated Milk Heat Stability and its Control

3. Judging and Grading of Condensed and Evaporated Milks Defects in Condensed and Evaporated Milks, their Causes and Prevention Uses of Condensed and Evaporated Milks PlainCondensed Milk Superheated Condensed Milk Frozen Condensed milk Conclusion Acknowledgement References

4. Introduction Condensed milk is one of the most important concentrated milk products used to preserve milk for long periods without refrigeration. It is made by evaporating a large portion of water from whole or standardised milk and, usually, by adding sugar to it.

5. Development The product was first developed by Gail Borden in 1856 in the United States. Its main purpose was to make milk safe, transportable, and long-lasting, especially in times when refrigeration and milk supply chains were poor.

6. The unsweetened type of condensed milk is called evaporated milk, where instead of adding sugar, the concentrated milk is sterilised to ensure safety. Hence, condensed and evaporated milks are classic examples of milk preservation by concentration — combining physical (water removal) and chemical (sugar addition or sterilisation) principles.

7. Definition Condensed milk is defined as the product obtained by evaporating a considerable portion of water from whole milk or standardized milk, usually followed by the addition of sugar to prevent spoilage.

8. It is a concentrated form of milk with increased total solids and reduced water activity, making it resistant to microbial growth and spoilage even at room temperature. According to dairy standards (as per FSSAI and Codex), sweetened condensed milk contains not less than 9% milk fat and not less than 28% milk solids-not-fat (SNF), while evaporated milk is the unsweetened version that is sterilised instead of being sweetened. Thus, Condensed Milk = Concentrated + Sweetened, and Evaporated Milk = Concentrated + Sterilised. Both are categorised under concentrated milk products, serving as preserved forms of fluid milk.

9. Composition and Standards The composition of condensed and evaporated milks depends on the extent of concentration, type of milk used, and whether sugar is added or not. In both cases, about 60% of the original water in milk is removed by evaporation. This raises the total solids and gives a thick, viscous consistency

10. 1. Sweetened Condensed Milk (SCM) Typical composition (approximate): Total solids: 70–74% Milk fat: 8–9% Milk solids-not-fat (SNF): 20–22% Sucrose: 40–45% Moisture: 26–30% pH: 6.0–6.3

11. Sweetened Condensed Milk (SCM) Standards (as per FSSAI/Codex): Minimum milk fat: 8% Minimum milk solids-not-fat: 28% Should be free from starch, coloring matter, or preservatives.

12. 2. Evaporated Milk (Unsweetened) Typical composition: Total solids: 25.5–28% Milk fat: 7.5–8% Moisture: 72–74% pH: 6.5–6.7

13. Evaporated Milk (Unsweetened) Standards: Minimum milk fat: 7.5% Minimum SNF: 17% No sugar added. Product must be sterilised and homogeneous.

14. Interpretation: “Condensed milk has high sugar and solids → high osmotic pressure → microbial growth inhibited. Evaporated milk has less total solids but is made safe by sterilisation after concentration”.

15. Food and Nutritive Value of Condensed and Evaporated Milks Condensed milk and evaporated milk are nutrient-dense forms of cow’s milk. During manufacture, only water is removed — the essential nutrients of milk remain in concentrated form. They provide high energy and nutrition in small quantities, which makes them valuable for children, invalids, and sweet and bakery products.

16. 1. Major Nutrients Present

17. 2.Energy Value Sweetened condensed milk: ≈ 330–340 kcal per 100 g Evaporated milk: ≈ 130–150 kcal per 100 g Hence both serve as concentrated sources of energy, especially for desserts and infant foods.

18. 3. Digestibility The heat treatment during manufacture partly denatures milk proteins, making them easier to digest. Fat globules become smaller after homogenisation (in evaporated milk), which also improves digestibility.

19. 4. Dietary and Industrial Importance Convenient and safe source of milk solids in regions without refrigeration. Used in infant formulas, sweets, bakery and confectionery products, coffee whiteners, and ice cream. High solids and sugar concentration make it ideal for energy-rich formulations.

20. Physico-chemical Properties of Condensed and Evaporated Milks Condensed and evaporated milks show distinct physical and chemical properties due to removal of water, heat treatment, and addition of sugar (in condensed milk). These properties determine their texture, viscosity, flavor, and shelf stability.

21. 1. Physical Properties

22. 2. Chemical Properties

23. 3. Functional Behaviour Heat denaturation of whey proteins improves viscosity and stability. Homogenisation reduces fat globule size, giving smooth mouthfeel. High solids increase osmotic pressure, ensuring preservation.

24. Role of Milk Constituents in Condensed Milk Each milk component plays a specific role in determining the texture, flavour, and stability of condensed milk. Understanding these roles helps in controlling defects and maintaining product quality

25. 1. Milk Fat Provides rich flavour, smoothness, and creamy texture. Must remain uniformly dispersed; otherwise, fat separation or creaming occurs. During heating, partial oxidation or caramelisation adds a pleasant cooked flavour. Excess heat or poor homogenisation causes fat coalescence and “oily layer” defects.

26. 2. Milk Proteins Casein and whey proteins are vital for structure and viscosity. Heat causes partial denaturation of whey proteins, which then interact with casein — giving desirable body and consistency. Proper protein balance prevents coagulation during heating. Too acidic conditions reduce stability and may lead to curdling.

27. 3. Lactose Acts as a major carbohydrate and flavour component. Concentration increases during evaporation; controlled crystallisation prevents sandy texture. In sweetened condensed milk, lactose + sucrose contribute to osmotic pressure and preservation. Excess crystallisation during storage can make the product gritty.

28. 4. Minerals (Calcium, Phosphates, Citrates) Control heat stability and buffering capacity of milk. High calcium and phosphate concentration can destabilise proteins during heating. Proper salt balance achieved by preheating and seeding ensures smooth texture and no coagulation.

29. 5. Water Present in small amount (~26% in SCM). Its removal increases concentration of all solids. Low water activity is the main reason for long shelf life in condensed milk.

30. Method of Manufacture, Packaging and Storage of Condensed Milk — Condensed milk is manufactured by concentrating milk, adding sugar, and packaging in an air-tight container. Each step ensures safety, stability, and desired texture.

31. 1. Method of Manufacture Step 1: Milk Reception and Standardisation : Fresh cow’s milk is received, tested, and clarified. Fat and Solids-Not- Fat (SNF) are adjusted — typically 8% fat, 28% SNF. Step 2: Preheating: Milk is heated to 85–90°C for 10–15 min. Purpose: kill bacteria, inactivate enzymes, and improve viscosity.

32. Step 3: Evaporation / Concentration : Performed in a vacuum evaporator at 55–60°C to prevent flavor damage. Removes about 60% of water. Total solids increase to ~28–30%. Step 4: Addition of Sugar : Sugar is added (~40–45%) to prevent microbial growth and provide sweetness. Creates high osmotic pressure → preserves product without refrigeration.

33. Step 5: Cooling and Controlled Crystallisation: Rapid cooling to 30–40°C with continuous stirring. Ensures lactose crystallises uniformly — prevents grainy texture. Step 6: Packaging: Filled into sterilised tin cans, laminated pouches, or bottles. Air-tight sealing prevents contamination.

34. 2. Storage Condensed milk is shelf-stable at room temperature due to sugar and low water content. Typical shelf life: 6–12 months. Must be stored away from sunlight and heat to prevent flavour and colour deterioration.

35. Method of Manufacture and Storage of Evaporated Milk — Evaporated milk is the unsweetened concentrated milk product. Unlike condensed milk, it relies on sterilisation instead of sugar for preservation.

36. 1. Method of Manufacture Step 1: Milk Reception and Standardisation Fresh milk is received, clarified, and tested. Fat and SNF are adjusted to desired levels (~7.5–8% fat, ~17–18% SNF). Step 2: Preheating Milk is heated to 85–90°C for 10–15 minutes. Purpose: kill bacteria, inactivate enzymes, and improve stability.

37. Step 3: Evaporation / Concentration Performed under vacuum at 55–60°C to remove ~60% water. Total solids after evaporation: ~25–28%. Step 4: Homogenisation Reduces fat globule size to prevent creaming. Ensures smooth, uniform texture in the final product.

38. Step 5: Sterilisation Filled into sterilised cans and heated at 115–118°C for 15–20 minutes. Kills remaining microorganisms, making the product shelf-stable. Step 6: Cooling Cans are rapidly cooled to room temperature.

39. 2. Storage Evaporated milk is shelf-stable at room temperature. Typical shelf life: 9–12 months. Store away from sunlight and high temperature to maintain flavor and color.

40. Heat Stability and Its Control — Heat stability refers to the ability of condensed and evaporated milk to resist coagulation or curdling during heating or sterilisation. It is a critical property to ensure a smooth texture and safe shelf-stable product.

41. 1. Factors Affecting Heat Stability

42. 2. Methods to Control Heat Stability 1. pH Adjustment: Correct pH (~ 6.6 – 6.8) ensures proteins remain stable during heating. 2. Salt Balance: Control Adjusting calcium, phosphate, and citrate levels prevents protein precipitation. 3. Vacuum Evaporation: Concentration under vacuum at moderate temperature prevents excessive protein denaturation.

43. 4. Preheating : Mild preheating (~85–90°C) denatures some whey proteins → improves interaction with casein → better stability. 5. Homogenisation : Reduces fat globule size → prevents cream separation and coagulation. 6. Rapid Cooling : Controlled cooling prevents lactose crystallization → maintains smooth texture.

44. Judging and Grading of Condensed and Evaporated Milks —Condensed and evaporated milks are judged and graded based on chemical composition, physical properties, and sensory characteristics. This ensures quality, consistency, and consumer acceptance.

45. 1. Sensory Evaluation:- Appearance & Colour: Light cream colour, uniform, free from dark spots or browning beyond normal. Maillard reaction. Consistency / Texture: Smooth, viscous, free from lumps, sandiness, or fat separation. Flavour & Aroma: Pleasant, sweet-cooked flavor in SCM; cooked but unsweetened in evaporated milk. Freedom from Defects: No gas formation, sedimentation, or off-flavours.

46. 2. Chemical and Physical Evaluation Total solids, fat, SNF, and sugar content should meet standards (FSSAI / Codex). pH and acidity within prescribed range. Viscosity to ensure proper body and mouthfeel. Microbial safety (especially for evaporated milk) — sterilisation ensures minimal microbial load.

47. 3. Grading Products are often graded as Extra, Standard, or Substandard, based on: - Compliance with chemical composition standards. - Sensory quality. - Consistency and appearance. Grading ensures market quality control and helps industries maintain consumer confidence.

48. Defects in Condensed and Evaporated Milks, Their Causes and Prevention - Condensed and evaporated milks can develop defects during manufacture or storage. Understanding causes and preventive measures ensures high-quality, stable products.

49. 1. Common Defects and Causes

50. 2. Prevention Measures Controlled evaporation and preheating to prevent overcooking. Proper addition and mixing of sugar to control osmotic pressure and prevent sandiness. Good hygiene and sterilisation to prevent microbial spoilage. Homogenisation to stabilise fat globules and maintain smooth texture. Controlled cooling and storage to prevent lactose crystallisation and colour changes. Monitoring total solids and pH to maintain body and flavour.

51. Uses of Condensed and Evaporated Milks - Condensed and evaporated milks are versatile milk products widely used in food processing, bakery, confectionery, beverages, and household cooking. Their long shelf life, concentrated nutrition, and stable texture make them highly useful.

52. Uses 1. Sweet Making and Confectionery 2. Bakery Industry 3. Beverages 4. Ice Cream and Desserts 5. Infant Foods and Nutritional Supplements

53. Types of Condensed Milk Condensed milk is available in different forms depending on processing and intended use:

54. 1. Plain Condensed Milk (Standard Sweetened Condensed Milk) Made by evaporating milk and adding sugar (~40–45%). Thick, viscous, sweet product used for: -Sweets and confectionery -Bakery items -Coffee or tea Shelf-stable for 6–12 months at room temperature.

55. 2. Superheated Condensed Milk Heated to a higher temperature than standard condensed milk (~115°C). Advantages : More sterile Improved shelf life Reduced microbial risk during storage. Used mainly in export, military, or tropical conditions where extended shelf life is critical.

56. 3. Frozen Condensed Milk Condensed milk that is rapidly frozen after concentration. Advantages: Maintains flavour and colour better Can be stored longer in frozen state Useful for bulk industrial use or transport to regions without reliable room-temperature storage. Thawing should be controlled to prevent texture defects.

57. Conclusion 1. Condensed and evaporated milks are important concentrated milk products that extend shelf life and provide a nutrient-dense, energy-rich form of milk. 2. Condensed milk is sweetened and preserved mainly by sugar, while evaporated milk is unsweetened and preserved by sterilisation. 3.The quality and stability of these products depend on careful control of: Milk constituents (fat, protein, lactose, minerals) Evaporation and heating processes pH, salt balance, and homogenisation 4. These products are versatile: used in sweets, bakery, beverages, ice cream, and infant foods. 5. Understanding their manufacture, physicochemical properties, and defect prevention is essential for quality control and industrial applications. 6. Condensed and evaporated milk remain classic examples of milk preservation, combining science and practical technology to produce safe, convenient, and nutritious dairy products.

58. Acknowledgement I would like to express my sincere gratitude to Prof. Sukumar De and all authors whose work in Outlines of Dairy Technology has provided the knowledge and insights used in preparing this presentation. I also thank my Professor Mrs. Jashandeep Kaur and my friends for guiding me in understanding the principles of dairy technology and helping me organise this material clearly. Finally, I acknowledge the support of my college library and online resources for providing access to additional reference material.

59. Reference 1. Sukumar De. Outlines of Dairy Technology. Oxford University Press. 2. FSSAI (Food Safety and Standards Authority of India) Standards — for composition and grading of condensed and evaporated milk. 3. R. K. Robinson. Dairy Technology: Principles of Milk Processing, 3rd Edition. 4. Wikipedia / Online Dairy Resources — for supplementary diagrams (where applicable). 5. Getty Images — for images used.