What is the effect of different types of milk on coffee

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Ultra-high temperature instant sterilized milk

High temperature sterilized milk (also known as normal temperature milk) is treated with instantaneous sterilization at ultra high temperature (135 ℃ to 150 ℃, 4 to 15 seconds), completely destroying the microorganisms and spores that can grow in it.

However, due to high temperature treatment, many heat-labile nutrients in milk, such as vitamins, will be destroyed, in which lactose will also be coked, protein and lactose will also have a certain Maillard reaction, resulting in milk browning and destroying the original flavor of milk. Ultra-high temperature sterilized milk can be preserved at room temperature for more than 30 days.

In order to ensure the long-term safety of sterilized milk, aseptic packaging must be used to package milk, which is also known as "Tetra Pak packaging", that is, a layer of aluminum foil is added to the carton to protect the product from light and oxygen in the air. thus, while preserving the original nutrients of milk, it can effectively inhibit the reproduction of microorganisms in milk and make the product commercially aseptic. And no need for cold chain storage and transportation.

Aseptic packaging is a process, including the selection of packaging materials and the aseptic filling process. Some careful consumers may have found that Tetra Pak packaged with UHT pasteurized milk is a "green" material made of paper, aluminum foil and polyethylene plastic.

This material can not only effectively prevent re-pollution, but also prevent the invasion of light, oxygen and microorganisms, so as to achieve the effect of quality, freshness, nutrition and delicacy. Secondly, the fresh milk sterilized by ultra-high temperature (UHT) and aseptic packaging can be filled aseptically so that it does not need to be refrigerated in storage and transportation.

Pasteurized milk

Pasteurization was not invented for fresh milk, but in beer brewing. In the 19th century, a brewery in France encountered a headache that beer would turn sour after brewing, so Pasteur, a famous microbiologist at that time, was asked to solve the problem.

Pasteur soon discovered that the chief culprit for sour beer was Lactobacillus, and nutritious beer was a paradise for Lactobacillus. The easiest way to eliminate Lactobacillus in beer is to boil the beer first so that it won't turn sour.

However, the beer boiled at high temperature has no flavor at all. Who else wants to drink it? Later, after repeated research by Pasteur, it was found that Lactobacillus could be completely killed when heated at a temperature of 50 ℃-60 ℃ for about 30 minutes, so it was tested in beer and found that heating beer at a temperature of 50 ℃-60 ℃ for half an hour could not only kill Lactobacillus, but also maintain the flavor of the beer.

Later, in memory of the method invented by Pasteur, the method was named pasteurization.

This method was used to sterilize milk until 1903 at the International Dairy Federation (IDF) inaugural meeting held in Brussels, Belgium, and gradually became the standard of dairy products in 1940, and milk sterilization was not used in China until 1947.

Before milk is sterilized, harmful microorganisms are the main source of danger to the human body. these microorganisms are easy to make people allergic to milk, resulting in vomiting, diarrhea and other phenomena, even life-threatening. The purpose of pasteurization is to completely kill the pathogens in milk and maximize the nutrition and flavor of fresh milk.

In addition, in order to inhibit the reproduction of harmless microorganisms, all pasteurized milk should be refrigerated between 0 and 4 ℃, and the shelf life should not exceed 20 days.

Because there are more microbes in milk, the flavor is not easily affected by high temperature like beer, and due to the demand of commercial production, someone later developed a treatment method of high temperature for a short time according to pasteurization, even with 72-76 ℃, 15 s, or 80-85 ℃, 10-15 s, also known as pasteurized milk.

Reclaimed milk

Restored milk, also known as "reduced milk" or "reduced milk", means that the milk is concentrated and dried into concentrated milk or milk powder, and then an appropriate amount of water is added to make the emulsion with the same proportion of water and solids in the raw milk. Popularly speaking, reduced milk is the milk reduced by blending with milk powder. There are two ways of processing: one is to mix different proportions of milk powder into fresh milk, and the other is a beverage made from milk powder.

People's attention to reconstituted milk is mainly focused on nutrition. To put it bluntly, "restored milk" means liquid milk reduced with milk powder, which is different from pure fresh milk processed with fresh milk. it is generally believed that due to the loss of nutrients after two times of ultra-high temperature treatment, the nutritional value of pasteurized milk is inferior to that of pasteurized milk, which is not as good as that of pasteurized milk which needs to be kept fresh at low temperature.

Of course, recovered milk is only a milk-flavored drink made from dairy products, so you can't drink restored milk as real fresh milk. many people still drink restored milk as fresh milk.

The easiest way to identify recovered milk is packaging. Since January 15, 2006, the State Council has stipulated that all yoghurt and sterilized milk produced with milk powder should be marked "recovery milk" or "recovery milk" in the adjacent part of the product name; yogurt and sterilized milk produced by adding part of milk powder to fresh milk should be marked "containing × ×% recovery milk" or "containing × ×% recovery milk" in the adjacent part of the product name.

"× ×%" refers to the mass fraction of whole milk solids in yoghurt or sterilized milk. The word "recovered milk" and the product name should be marked on the same main display page of the packaging container; the word "recovered milk" must be conspicuous, the font size is not less than the font size of the product name, and the font height is not less than 1/5 of the height of the main display page.

ESL milk

ESL (Extended Shelf Life) is a kind of food fresh-keeping technology, which can reduce the content of bacteria, the probability of deterioration and prolong the shelf life of products under the condition of maximum preservation of product freshness. In the past, it was widely used in North American whipped cream and coffee cream, but now it is also used in milk processing.

ESL technology includes a series of links, such as farm hygiene, quality control of raw milk, sterilization technology, ESL filling and processing methods, processing key points control, processing equipment, storage, transportation and distribution of finished products, etc., through these procedures to maintain the freshness of products, improve the safety of microbial level, and prolong the shelf life of products.

ESL, also known as the technology for producing extended shelf-life products, existed in North America in 1960, when it was mainly used to produce products with slow circulation, such as stirred cream and coffee cream. Now this technology has been extended to other high value-added products as well as regular drinking milk, and ESL milk has become a proprietary acronym, referring to the whole system process from raw product quality to final sale.

However, there is no legal concept for ESL milk. Generally speaking, ESL milk is defined as a product with a longer shelf life than pasteurized milk.

But it is not until recent years that ESL technology has been widely used in milk. In North America, the shelf life of ELS milk is generally 45-60 days. In recent years, ESL milk technology has attracted more and more attention from the dairy industry all over the world, because ELS milk can meet the nutritional, fresh, hygienic and healthy needs of liquid milk that consumers want.

For consumers, "quality" means that the product tastes good and can be kept fresh in the refrigerator. In short, in order to maintain and increase market share, the goal of processors should be to meet or establish the quality expectations of consumers. In order to meet the challenge, milk processors must focus on improving quality and prolonging the shelf life of their products.

In a word, the use of ultra-high temperature sterilization not only destroys many nutrients and most vitamins in fresh milk, but also makes calcium ions that can be easily absorbed combine with casein in milk to form complexes that are not easy to be absorbed.

Therefore, the nutrients in "restored milk" are actually a large number of energy substances such as common protein, fat and sugar that exist in foods such as rice, noodles and meat, and the gap between them and fresh milk is self-evident.

This is based on the data No. 130 of the International Dairy Federation (IDF) in 1981, UHT sterilization makes the denaturation rate of whey protein up to 91%, the increase of hydroxymethylfurfural (hydroxymethylfurfural), that is, the reaction between amino group and carbonyl group; serious loss of sulfur-containing amino acids and lysine The destruction of vitamin B1, vitamin C and folic acid is 5-10 times higher than that of pasteurization, making the calcium ion that is easy to be absorbed into tricalcium phosphate which is not easy to be absorbed.

After two times of ultra-high temperature treatment, the nutritional value of "recovered milk" is even lower than that of ice cream and ice cream.