Nowadays, people pay more and more attention to the health and safety of food, so there are a variety of products used for food preservation, such as plastic food containers, microwave bowls, cling film, ziplock bags, and sealed cans. In addition to these, there are also some new and luxurious products. For the preservation of vegetables, it is important to retain moisture while avoiding leaf decay.
People are not unfamiliar with the precautions for daily food preservation, but they often overlook the most important point - blocking light. For the preservation of liquid foods like milk, light is their enemy. Blocking light is a crucial step in ensuring food packaging and largely determines the freshness of the food. The taste and quality of food are greatly affected by light waves, and the harm caused by light can even be faster than the growth of bacteria.
Taking milk as an example, vitamins and proteins are the most important nutrients in milk and should be protected from light. Once vitamins and proteins come into contact with light, they will be greatly lost. Even for the popular ultra-high temperature instant sterilized milk that does not require refrigeration, it still needs to be tightly protected and packaged with materials that prevent recontamination in order to have a longer shelf life. Aseptic packaging can provide a completely light-shielding and antioxidant environment for the product.
The packaging paper for UHT milk is a material composed of paper, aluminum foil, and polyethylene plastic layers. This material can effectively prevent recontamination, oxidation, and the invasion of microorganisms. Moreover, it can effectively block the harm of light, thus achieving the effect of maintaining the quality, freshness, nutrition, and taste of food.
When it comes to milk preservation, the most important thing is not to expose it to sunlight or artificial light. These lights can damage the vitamins in milk and cause the milk to lose its aroma. Therefore, fresh milk should be stored in a cool place, and putting it in the refrigerator is the best choice. If milk is stored in the refrigerator, make sure the bottle cap is tightly closed to prevent other smells from getting into the milk. If there is any leftover milk after pouring it into a cup, teapot, or other containers, it should be covered and put back in the refrigerator. Do not pour the remaining milk back into the original bottle. Also, it is worth noting that milk should not be frozen, as it can affect its quality. Simply placing milk in the refrigerated compartment of the refrigerator is sufficient.
Here, let me introduce how to choose good quality milk. Fresh milk should be a milky white or slightly yellow homogeneous gel-like fluid, with no sediment, lumps, impurities, starchiness, or strange smells. When shaking fresh milk in a cup, it should easily stick to the cup walls. When a drop of milk is dripped onto glass, the droplet should be round and not easily spread. After cooking, there should be no coagulation or precipitates. Milk that meets the above characteristics can be safely consumed.
Tips from the editor:
Precooked food should not be stored for too long, as the nutrients in the food will undergo transformation over time, causing the food to lose its original color, taste, and aroma, and even allowing bacteria to grow. Storing precooked food for a long time can cause it to become sour, develop a film, or mold. Consuming such food can lead to food poisoning. Some people may think that storing food in the refrigerator will solve these problems, but this is not correct. Even when stored in the refrigerator, mold can still occur over time, as the temperature in the refrigerator is generally above 1°C. Although it can inhibit bacterial growth, it does not kill bacteria, and some bacteria can even multiply. Therefore, precooked food should not be stored for too long.
