Milk is the first food of young mammals and a nutrient-rich, white liquid produced by the mammary glands of females' mammals. It is a mixture of fat and high-quality protein in water, which contains some carbohydrate (lactose (4.8%), vitamins and minerals (0.8%). Furthermore, there are ranges of other individuals' products that can be made from milk, which are also known as dairy products, a product containing milk or made from milk, such as; butter, cream, and ice cream. Water, carbohydrate, fat, protein, vitamins and minerals are the key components that are found in cows' milk. Water is the largest component of milk and is present at a level of approximately 87 to 88%. Not only it is the largest component in milk but also considered important for human nutrition because the body uses water in all its cell, organs, and tissues to help regulate its temperature and maintain other bodily functions. Calcium is one of few minerals found in milk, which play an important role in muscle contraction, transmitting messages through the nerves and realizes of hormones, therefore lack of calcium can lead to weakened bones.
This case study report aims to gain more knowledge of milk and understand the importance of milk for human nutrition.
The quantity of milk production from cows largely depends on the environment it’s in. The more stable the environment, the more production of milk. Many environmental factors are contributing to the production of milk, these include: weather, climate, geography, feed and accommodations. The main environmental variable contributing to the reduction of milk production is heat stress. The quantity of production of yield is highly affected by climate changes, the increment of temperature and humidity leads to a significant decrease in milk production, as cow are more comfortable in cooler climate. Which means heat stressed cattle may try to reduce the body heat through thermoregulatory mechanisms which in turn affect feed conversion efficiency and lead to decreased milk production. The weather and climate can also alter the quality of feed, which further can affect the quantity and quality of milk produced. Not only feed and climate but also where the cow lives can decrease and increase the production of milk, for instance, when cow have more comfortable places to rest, space to graze and farmer who to keep everything clean, those cows are more productive compare to cow in uncomfortable environment.
Cows are milked using vacuum cups which are attached to the cow's teats, then the milk is sent through stainless steel pipes to large refrigerated vats or silos, then stored at 5 Celsius or less for no more than 48 hours. Using tankers that have special stainless-steel bodies which are heavily insulated are used for milk transportation to the processing factory. Sample of milk is tested for antibiotics, fat and protein contractions and temperature before the milk enters the factory processing area for further process. Once the milk is approved for use, it is pumped into storage silos where it undergoes pasteurization, homogenization, separation and further processing. Pasteurization is an important technique in the production of milk as it helps to destroy any harmful bacteria and micro-organism that can cause food spoilage. Homogenization is when milk is put under pressure through fine nozzles, which evenly disperses fat globules, this stops the cream separating and rising to the top, allowing a more consistent texture and taste. Separation involves spinning the milk through a centrifuge to separate the cream from the milk, afterwards, the cream and remaining milk are remixed to provide the desired fat content for the different type of milk being produced, for instance, whole milk, low-fat milk, and skim milk. Lastly, when the is ready to be packaged it travels through the pies to the automatic packaging machines that fill and seals the milk into a milk bottle.
According to FSANZ, to sell the milk, the manufacturer is required to make sure that the milk for retail sale contains at least 3.2% fat and 3% protein. Also, they need to make sure that the skim milk contains a maximum of 0.15% of fat and a minimum of 3% of protein (FSANZ 2015, Dairy Standard). The code allows the manufacturer to adjust the components of milk, such as protein, lactose, fat or vitamins and minerals by adding or removing those components to produce a standardizes product. Functional properties describe how ingredients behave during preparation and cooking, how they affect the finished food product in terms of how it looks, tastes, and feels. Flavor is one of the functional properties in milk. The flavor of milk is mild and slightly sweet. Due to the presence of emulsified fat, the colloidally dispersed protein, carbohydrate lactose and milk salts causes the characteristic of mouthfeel. According to Schiano, A. Harwood, W. & Drake (2017), the key components that contribute to sweet and salty taste is due to lactose and milk salt and the flavor changes in milk due to light exposure, which is why the off – flavor was linked to sunlight. Richer flavor is associated with homogenization processing because the primary function of homogenization is to prevent creaming or the rising of fat to the top of the milk container. The result of homogenization causes the milk to maintain a more uniform composition with improved body and texture, a whiter appearance, richer flavor and more digestible curd.
In conclusion, the overall finding indicates the importance of cow's milk in the Australian diet. the finding also demonstrates how the dairy product including fresh frozen or dried, provide a variety of nutritional and functional properties and also play a significant role in the food system. The research also indicates that environmental variable such as climate change can reduce the amount of milk production and the food components that are found in cow's milk.
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