Milk processing involves the steps to ensure milk is safe, nutritious, and extends its shelf life. The milk is collected, filtered, and pasteurized to eliminate harmful microorganisms while preserving essential nutrients. This process also improves its taste and ensures consistency in quality.

The first step in milk processing is filtration. Milk is passed through fine mesh filters to remove impurities like dirt and hair, ensuring it’s clean and safe for further processing.

Pasteurization is a crucial stage in milk preservation. The milk is heated to a specific temperature for a set period to kill harmful bacteria without altering its nutritional value. This process prevents spoilage and extends shelf life.

To further preserve milk, it is often homogenized. Homogenization breaks down fat molecules, ensuring the milk remains evenly distributed and smooth. This process prevents cream from separating, improving its texture and appearance.

Packaging is the final step, where milk is sealed in containers such as bottles, cartons, or pouches. Proper packaging ensures the milk remains uncontaminated and preserves its freshness during transportation and storage.

The development of the diary industry is mainly in the hands of the Fulani woman. Product development and marketing has been static because of their limitation in western education.

Transporting and Nomadic way of life has little or no government participation or control of the traditional diary industry. In this article you will be studying about milk and its products.

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Definition of Milk

Milk is a nutrient-rich liquid produced by the mammary glands of female mammals, including cows, goats, and humans.

It serves as a primary source of nutrition for newborns, providing essential proteins, fats, carbohydrates, vitamins, and minerals. Milk is commonly consumed directly or processed into various dairy products like cheese, yogurt, butter, and cream.

Properties of Milk

1. Taste and Odour: Milk has in it a skightly sweet taste and a milk aromatic flavour. The sweet taste comes from lactose while the flavour comes from the fat.

2. Labour: Normal milk has a yellows white colour because of the presence of fat and small amounts of colouring matter. The breed of the animal and type of feed has an affect on the colour of the milk is deeper yellow in colour when animals are on pasture that when they are concentrate feed.

3. Specific Density: Milk is heavier than water because of the dissolved constituents. The specific gravity of milk is between 1.02 and 1.034.

4. Acid-Base State of Milk: Milk has a pH of 6.6 – 6.8 and is slightly acidic. The substances giving milk its apparent acidity are the phosphates, citrates, casein, albumin and dissolved carbon dioxide.

5. Freezing and Boiling Points of Milk: Milk freezes from about 31°F milk and whole milk have the same freezing point. The boiling point of milk is higher than that of 14°F.

6. Cream Rising: When whole milk stands for a while. The fat rises to the top because it is lighter than water. eventually forms a layer packed with fat globules called cream. When cream is agitated by chuming, larger clump forms to yield butter.

7. Foaming: Milk foams on heating. This is due to air which becomes incorporated into the thin layers of milk formed by coagulating proteins.

Processing of Diary Product

The processing of dairy products involves several key steps to transform raw milk into a variety of consumable items. These steps ensure safety, quality, and enhance the shelf life of the products. The main stages include:

1. Milk Collection and Cleaning: Fresh milk is collected from dairy farms, filtered to remove impurities, and chilled to maintain freshness.

2. Pasteurization: The milk is heated to a specific temperature to kill harmful bacteria while preserving its nutritional value. This step prevents spoilage and ensures safety.

3. Separation and Homogenization: Milk is separated into cream and skim milk, and homogenization ensures the fat is evenly distributed throughout the milk to avoid separation.

4. Fermentation: For products like yogurt or cheese, specific bacterial cultures are added to ferment the milk, converting lactose into lactic acid and changing its texture and flavor.

5. Packaging: The final dairy products are packaged in sterile containers to prevent contamination, ensuring freshness and extended shelf life.

Each dairy product, such as cheese, yogurt, butter, and cream, undergoes additional specific processes to achieve the desired texture, flavor, and consistency.

Reasons for Processing Milk

Raw milk goes sour when kept at ambient temperature over a period of time. Milk obtained from the udder of an animal contains different types of bacteria some of which could cause disease. So milk needs so much form of processing for various reasons.

1. Safeguard Public Health: This is achieved through either pasteurization or sterilization of milk and milk products. The process ensures the domination of disease causing pathogens.

2. Reduction of Water Content of Milk: This reduces the bulkiness of milk and cost of transportation. Milk contains about 87% water. Thus evaporated or condensed milk products are cheaper to transport.

Enhances shelf life and reduces storage space processed milk has longer without getting bad and then condensed the balkiness reduced.

Production of other desirable products milk can be processed into other products such as cream, cheese, butter. To confirm to industrial and health regulation.

Methods of Processing Milk

1. Pasteurization: This is a process by which milk or milk products are heated to a specific temperature and held there for a specific time to destroy all pathogenic bacteria. Are two types of pasteurization.

i. Holding vat or batch method
ii. High temperatures short time method.

In the holding vat method, milk is heated in the holder pasteurizer at temperature of 62°C for about 30 minutes. The pasteurized product is then cooled for packaging.

The short time method involves heating the product at a high temperature usually at 72°C for 15 seconds.

Pasteurization kills about 99.6% of all bacteria in milk.

2. Sterilized Milk: This is a product obtained from raw milk that is treated to high temperature 92.97°C for a period of between 16-30 minutes so that all micro-organisms are destroyed.

The flavour of pasteurized milk is not very pleasant and such a high temperature heating may result in decrease in vitamin content.

3. Evaporated Milk: This is the product of evaporating water from whole milk at 70-73°C in a vacuum. About 50% of the water in original milk is boiled off.

This process can be achieved in a home by slowly boiling milk in a pot. Commercially this product is filled into tins and sterilized under pressure. The storage life of the product is unlimited normal temperature as long as the tin or container is not opened.

4. Other Process: A few other processes are used to make milk more acceptable and to improve it keeping quantity. Milk can be homogenized before heat treatment to reduce fat globule size so that will remain dispersed and will not form a cream layer.

Milk is sometimes frozen as a means of having a regular supply throughout the year. A rancid flavour often develops in a cow milk as the fat globules membrane is broken by freezing.

Process of Making Milk Powders

Dried Milk Powders are very suitable products for the developing countries because, dried milk can be kept without
i. refrigeration

ii. be transported easily

iii. be mixed easily with other food stuffs

iv. available all year round

Whereas milk, skim milk and butter milk can all be successfully dried. This involves pasteurization then condensation into one-third of its volume then dried by roller or spray drying.

Packaging and Distribution

Methods of packaging and distribution are tailored to the customers, requirements and income. In many cases milk is best left unpackaged from containers to provide the cheapest possible supply to low-income customers.

In most countries, there are some customers willing to pay for packaged milk. Despite the higher cost, the advantages of packaged milk to the customer are:
i. Convenience
ii. Milk that has better keeping qualities
iii. Milk is accurately measured and safe from adulteration

A variety of packaging methods are used include returnable glass bottles, plastic bottles, card-board cartons, plastic sachets and sealed cans. Dried Milk Powders is a very suitable produced for the developing countries.

In conclusion, Milk processing is necessary in order to extend its shelf life of different methods of processing are available farmers should choose methods that can be easily adapted.

Milk is an important product which contain all the essential nutrients. The properties of milk in most cases determines is determined by its constituents. Processing of milk is necessary and the various processing methods have been highlighted.

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