Food safety is an important issue related to people's livelihood, and among the many technical means to ensure food safety, sterilization treatment undoubtedly occupies a core position. Among them, high-temperature sterilization and pasteurization are two common food sterilization technologies, each of which plays an indispensable role in the food industry. Today, we're going to take a closer look at the differences between these two sterilization methods and reveal how they keep our tables safe.
1. High temperature sterilization.
High-temperature sterilization (also known as ultra-high temperature instantaneous sterilization or UHT sterilization) is a sterilization method that uses extreme high temperatures to heat treat food for a short time. It works by heating food to a temperature of 135-150 or even higher for a few seconds to tens of seconds to completely kill microorganisms such as bacteria, yeast, mold and viruses in food. Because the instantaneous high temperature kills all microorganisms with low heat resistance, products that have been sterilized by high temperature usually have a long aseptic shelf life and can maintain stable quality without refrigeration, such as ambient milk, canned food, etc.
2. Pasteurization.
Compared with high-temperature sterilization, pasteurization is much milder. This method was invented by French scientist Louis Pasteur in the 19th century, hence the name. Pasteurization is to heat food to 60-85 and maintain it for a certain period of time (generally between 15 seconds and dozens of minutes), the main goal is to deal with harmful microorganisms in milk, juice and other fresh foods, especially salmonella, tuberculosis bacillus and other pathogens, while retaining the original flavor and nutritional value of food as much as possible.
Difference and comparison: temperature and time: high temperature sterilization uses a temperature much higher than pasteurization, but the processing time is relatively short; Pasteurization, on the other hand, requires a longer heating time to ensure effective sterilization, although the temperature is relatively low.
Degree of microbial killing: high-temperature sterilization can destroy almost all microorganisms in food, including bacillus, so it can achieve commercial sterility and greatly extend the shelf life of food; Although pasteurization can kill most pathogenic microorganisms, it may still leave some heat-resistant microorganisms and spores, so pasteurized food needs to be refrigerated and have a short shelf life.
Food nutrition and taste: due to the long-term effect of high temperature sterilization, it may lead to changes in the structure of some heat-sensitive vitamins and proteins, affecting the nutritional value and taste of food; Pasteurization can reduce these negative effects to a certain extent due to the lower temperature, and better maintain the original flavor and nutrient content of food.
High-temperature sterilization and pasteurization have their own advantages and disadvantages, and the choice of sterilization method depends on the specific type of food, storage conditions, and consumer needs for taste, nutritional value and shelf life of the product. Whether it is high-temperature sterilization or pasteurization, it is a key process to ensure food safety and improve food quality in the modern food industry, and jointly build a safe line of defense for food in our daily life.