WHAT IS MILK?
milk is a liquid substance secreted by the mammary glands of mammals. It is one of the most complete and balanced foods due to its nutritional composition.
Although those of plant origin are commonly referred to by this term, according to the Codex Alimentarius , this is not correct. Those of vegetable origin are referred to as "beverage". Soy beverage, almond etc. and only those of animal origin as "milk".
Defined as "normal secretion of dairy animals obtained from one or more milkings without any kind of addition or extraction, intended for consumption as liquid milk or for further processing,"
Its production: is one of the most consumed foods worldwide. Europe is one of the largest producers. In Spain, the most consumed is pasteurised UHT milk.
Its nutritional value:
- Proteins : 80% corresponds to casein , which has the capacity to favour the intestinal absorption of calcium. The remaining 20% corresponds to whey.
- Fats : milk is a fat emulsion, the largest percentage of which (around 98%) is made up of triglycerides. The rest is made up of phospholipids, free fatty acids, sterols and fat-soluble vitamins.
- Carbohydrates : the most prominent is lactose (8glucose + galactose).
- Vitamins: contains all vitamins except C, which is present in minimal concentration. Those water-soluble vitamins are found in whey and are lost in the processing of some products, e.g. cheese.
- Minerals : calcium and phosphorus are the most abundant, although others such as zinc, manganese, iodine, potassium, sodium, etc. are also present.
- Water : constitutes more than 87% of the total composition of milk.
BENEFITS OF MILK AND MILK DERIVATIVES
- High nutrient density.
- High in protein . Contains essential amino acids
- Provides good amounts of calcium, fat-soluble vitamins and B group vitamins:
- Milk provides 0.19 mg of vitamin B2 in 100 ml. We can cover 80% of the recommended daily amount of vitamin B2.
- There are more and more variants on the market: lactose-free, calcium-enriched, with lower fat content, etc. As well as vegetable drinks with similar values.
- The vitamin A and D are lost when skimming the milk. If we choose whole milk, we get the following benefits:
- Vitamin A contributes to the proper maintenance of mucous membranes, skin and vision.
- Vitamin D: Contributes to the proper absorption and normal utilisation of calcium and phosphorus and to the maintenance of adequate blood calcium levels.
WHAT ARE THE MILK DERIVATIVES?
Fermentation is a biochemical process of incomplete oxidation in the absence of oxygen in which the final product obtained is different from the initial one.
Produced by coagulating milk and obtained by lactic fermentation of Lactobacillus and Streptococus thermophilus from pasteurised milk.
The advantages of fermented dairy products are:
-Digestibility is improved, as during the fermentation process a high lactose content is transformed into lactic acid. There are individuals who, despite not being able to tolerate normal milk, can consume this type of product.
-Nutrient absorption is improved, e.g. calcium absorption.
This is a fermented milk with higher protein degradation, so it is considered a very digestible product. (lactic ferments + yeast: alcohol)
It has a higher probiotic capacity than yoghurt. It is a more acidic product.
-Increases the biological value of proteins
-Formation of B vitamins
It acts as a probiotic by re-establishing the intestinal flora
-Low lactose content.
A milk derivative produced by the coagulation of milk through the use of natural rennet or other substances.
For the production of cheese, the milk must be thoroughly sanitised. Depending on the amount of fat in its composition, we can obtain different types of cheese.
HOW IS MILK PRODUCED?
The first step is to obtain the milk from the cow through a system of milking . Once it is extracted, it is stored in tanks that allow it to be kept refrigerated at an average temperature of 4 degrees.
From the tank it is transferred to a refrigerated tanker and transported to the dairy, where it is transferred to a buffer tank.
In this tank certain micro-organisms are partially eliminated.
In the centrifuge skimmer , impurities are removed and the cream is separated from the whey and the pasteurisation process is carried out.
Next, a reconstruction of the fat is carried out, depending on whether we want to obtain whole, semi-skimmed or skimmed milk and what we are going to use it for. Finally, it is pasteurised again.
DIFFERENCES BETWEEN UHT, STERILISED AND PASTEURISED MILK
According to the treatment that is applied to the milk in order to preserve it. There are different types.
This prevents the proliferation of pathogenic microorganisms such as Lysteria. The temperature must exceed the temperature above which the most heat-resistant micro-organism disappears.
- UHT milk: is characterised by the fact that it is heated at high temperatures for a short period of time, exactly 135°C for at least one second, followed by a cooling process. Proteases (responsible for degrading protein) are not inactivated, so that higher amounts of vitamins are retained and an essential amino acid called lysine is not destroyed.
It eliminates the micro-organisms present and extends its shelf life by up to 6 months without the need for refrigeration.
- Sterilised milk: is a process characterised by subjecting milk to temperatures higher than 100º for 15 minutes. The reason for subjecting milk to high temperatures for a longer period of time is that despite the elimination of microorganisms, there is also a loss of vitamins and minerals. Changes in taste or colour may occur.
- Pasteurised milk : it is characterised by subjecting the milk to temperatures below 100º for short periods of time and then cooling it to temperatures below 6º. The average temperature used is 71º.
The protein cheeses are variants of traditional cheeses, with the main difference being that the protein content is higher and the fat content is lower. They contain virtually no carbohydrates.
These cheeses are intended to be adaptable to all types of diets, especially those high in protein: for protists or people with healthy habits. They have been created to satisfy the needs of all people who want to continue enjoying this product, but with a better nutritional composition.
Lactose-free , although for more information, it is recommended to read the labelling of each product individually.
Typically, are manufactured with: pasteurised cow's milk, salt, lactic ferments and vegetable coagulant.