Why does foamed milk bubble up

I believe that everyone has seen bubbles appearing in foamed milk. This is mainly because shaking the milk powder up and down too vigorously when mixing it can cause bubbles to form. In addition, the lack of viscosity of milk powder when mixed with water can also cause bubbles. This situation will not affect the nutritional value of the milk and you can consume it with confidence. For the nutritional value of brewed milk, please refer to the content of the article.

Since milk powder is made from fresh liquid milk and wet mixing to ensure the freshness of the milk powder, it is easy to produce foam. Excessive bubbles are produced when mixing milk powder, mainly due to incorrect up and down shaking or shaking with excessive force. The presence or absence of foam is a physical phenomenon. Milk powder can form a stable colloidal solution when dissolved in water. Due to the surface tension and viscosity of the solution, lasting foam will be produced when stirred or mixed. Different types of milk powder have different ingredients, and the viscosity and surface tension of the colloidal solution formed are different. When the surface tension and viscosity are larger, more and larger bubbles are formed and last longer, and vice versa. On the other hand, the foam produced by mixing milk powder is related to many factors such as the temperature of water, the texture, shape, smoothness of the container, the intensity of stirring or vibration, etc., so the foam formed may be different. In fact, it is very easy to remove bubbles, just add defoaming agent or use physical methods. However, chemicals such as defoaming agents are not allowed to be added to infant formula. Different mixing methods for the same can of milk powder will produce different degrees of foam, which will not affect the quality of the milk powder.

Milk is one of the oldest natural beverages and is known as "white blood". Its importance to the human body can be imagined. Milk, as the name suggests, is squeezed out from female cows. In different countries, milk is divided into different grades.

Milk is rich in minerals, calcium, phosphorus, iron, zinc, copper, manganese and molybdenum. The most valuable thing is that milk is the best source of calcium for the human body, and the calcium-phosphorus ratio is very appropriate, which is conducive to calcium absorption. The types are complex, with at least 100 kinds, and the main components are water, fat, phospholipids, protein, lactose, inorganic salts, etc.

The inorganic salts in milk are also called minerals. Milk contains cations such as Ca²⁺, Mg²⁺, K⁺, Fe³⁺ and anions such as PO₄³⁻, SO₄²⁻, Cl⁻; in addition, there are trace elements I, Cu, Zn, Mn, etc. Calcium in nature exists in a chemical state. Only after it is passively absorbed by plants to form biologically active calcium can it be better absorbed and utilized by the human body.

Milk is rich in active calcium and is one of the best sources of calcium for humans. One liter of fresh milk contains about 1,250 mg of active calcium, ranking first among many foods. It is about 101 times that of rice, 75 times that of lean beef, and 110 times that of lean pork. Not only is it high in content, but the lactose in it can promote the absorption of calcium by the human intestinal wall with an absorption rate of up to 98%, thereby regulating calcium metabolism in the body, maintaining serum calcium concentration, and promoting bone calcification. Good absorption is especially important for calcium supplementation. Therefore, the statement that “milk can supplement calcium” has scientific basis.