The main components of milk are protein, fat, lactose, and various minerals and vitamins. It is especially rich in calcium and phosphorus; a glass of milk (about 250ml) contains half of the daily human requirement for calcium. However, if people do not pay attention to scientific cooking and drinking methods when consuming milk, its nutritional value will be greatly diminished. So, what mistakes do people make when drinking milk?
High-temperature and prolonged heating
If the heating temperature reaches around 100℃, the lactose in the milk will begin to caramelize, turning brown, and gradually decompose to produce lactic acid and a small amount of formaldehyde. High-temperature and prolonged heating also causes significant loss of vitamins in milk. Therefore, milk should only be heated until it just comes to a boil and then removed from the heat; it should not be boiled for a long time.
Adding sugar while cooking
Lysine in milk reacts with sugar at high temperatures in a chemical reaction called the Maillard reaction, producing a toxic substance—fructoselysine, which is harmful to human health, especially for children. If you want to drink sweet milk, you should add the sugar after the milk has been cooked and has cooled slightly. Similarly, milk should not be cooked with chocolate, as chocolate is rich in oxalic acid. When cooked and eaten together, the calcium and oxalic acid in the milk will combine to form calcium oxalate, which is not easily absorbed. This can also cause symptoms such as diarrhea. Therefore, it is best to consume them separately.
Drinking milk on an empty stomach
When the stomach is empty, gastrointestinal motility is faster, so milk does not stay in the gastrointestinal tract for long. It cannot make full contact with digestive enzymes, and its nutrients are "hurriedly" excreted into the large intestine before they can be digested, preventing full absorption and utilization. The correct way to drink milk is to consume it with starchy foods such as steamed buns, bread, or pastries. This allows the protein, calcium, and other nutrients in the milk to remain in the gastrointestinal tract for a longer period under the action of starch, ensuring they are fully absorbed and utilized.
Mixing with acidic foods
After milk enters the gastrointestinal tract, it is first acted upon by pepsin in gastric juice and trypsin, which combine with the protein in the milk before it enters the small intestine. If acidic drinks or fruits are consumed at this time, the protein in the milk will coagulate with fruit acid and vitamin C into clumps. This not only affects digestion and absorption but can also lead to symptoms such as diarrhea, abdominal pain, and bloating.
Improper storage
Some people like to chill or freeze milk in the summer. When the milk is chilled below zero degrees Celsius, its fat and protein separate, and the casein forms a powdery coagulate, significantly weakening its flavor and making its nutrients less easily absorbed. Frequently drinking chilled milk can also easily promote the recurrence of gastrointestinal diseases such as ulcers, cholecystitis, and enteritis. Others also like to store leftover milk in a thermos. This is not advisable, as bacteria from the milk or the air in the upper part of the thermos will enter a nutritious incubator, multiplying rapidly and causing the milk to sour and spoil within a few hours. Vitamins B and C will also be largely lost. Therefore, it is best to drink the cooked milk slightly cooled immediately.