In a study published in 2001 in the Journal of Epidemiology and Community Health , carried out with men between 45 and 59 years old, it is stated that a diet rich in milk does not increase the risk of diseases or heart attacks. What’s more, it may even have a protective effect, regardless of the type of milk consumed . In short, this result of what is called a “cohort study” – where a group of people with a certain condition and/or treatment is monitored and compared with another that is not affected by the characteristic to be studied – says that the bad reputation that milk – especially whole milk – has as a cause of increased cholesterol is just that, a bad reputation. By the way, in that same study, known as the Caerphilly cohort study (it was carried out for 10 years in the Welsh city of Caerphilly and five other surrounding towns) it was found that there is a correlation between orgasm and mortality : The risk of dying from a heart attack is – and take note – 50% lower among those men with a “high frequency of orgasms”, to put it finely.
The content of milk
But back to the milk. Biologically speaking, the only role that this white fluid – milk, I insist – has is to feed and provide immunological protection to young mammals. Food of human beings since prehistoric times, milk is, along with honey, the two items of the diet whose only function in nature is to serve as food. Therefore it is not surprising that it has a very high nutritional value. More than 100,000 different molecular species have been found in milk , although, in essence, we can say that milk contains water (around 87%), fat (4%) and non-fatty solids (9%), a sac where they get vitamins, proteins, sugars such as lactose, acids, minerals…
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| image credit - wikipedia |
If its composition is already quite complex, it is even more fascinating to determine its structure. Due to the role it plays in nature, milk, as we all know, comes in liquid form. Something very curious if we take into account that it contains less water than most fruits and vegetables . If we observe it through a microscope we will find the following. At 5X magnification it looks like a cloudy liquid; At 500X, spherical droplets of fat appear, the fat globules . And at 50,000X, enchantments of molecules known as casein mycelia – the main protein in milk – appear. Casein , along with other surfactant molecules, which have a part that dissolves in water and another that dissolves in fat, play a crucial role because they delimit the fat globules, stabilize them and ensure their dispersion in water . In other words: these molecules ensure that fat droplets electrically repel each other, preventing them from clumping together.
The formation of cream
Now, sometimes this is inevitable because these droplets are in constant motion. Those that go faster sometimes skip this security check, colliding and getting stuck. This causes a forward escape: as they become larger, the repulsive forces become smaller and smaller and more and more pieces of fat join together. Thus, little by little they increase in size until they rise to the surface: the cream has just formed. By heating the milk this process is accelerated because the heat increases the speed of the fat globules.
When the temperature rises above 80º C, the milk proteins coagulate , which has two effects: they stop protecting the fat globules and form a thin film on the surface. In addition, some proteins contain sulfur atoms that denature at temperatures above 74º C: sulfur reacts with hydrogen forming hydrogen sulfide, which has that characteristic smell of cooked milk or rotten eggs.
But the main problem with milk is that it is a food that is very susceptible to spoilage . Due to its composition, it is especially appetizing for a multitude of microorganisms, including those that cause poisoning and those that produce enzymatic changes, responsible for the rancidity of milk fat.