Soy milk is perishable = fresh? Nutritionist: Wrong idea

There is a lot of knowledge in drinking soy milk! Does the fact that soy milk easily goes rancid mean it is “fresh and additive-free”? There are rumors on the Internet that "it is normal for soy milk to go bad", "soy milk will go bad only if preservatives are not added", "freshly ground soy milk also goes bad easily" and other seemingly plausible statements. Nutritionists say that soy milk is rich in nutrients and is a food that easily goes rancid, but it is not appropriate to judge the freshness of soy milk by the speed at which it goes rancid, as this is a misconception.

To avoid buying soy milk that easily goes rancid, consumers should pay attention to antibacterial management and the storage environment of soy milk after purchase.

Nutritionist Cheng Hanyu said that there are reasons for food spoilage. The main reasons are that microorganisms (including bacteria, yeast and mold) decompose sugar, protein and other nutrients in food to produce low-molecular substances such as ammonia, hydrogen sulfide, ferment, ketones, etc., which make food have bad odor and taste; the activity of various enzymes contained in the food itself is enhanced, causing the decomposition of food components and making the food spoil; and the temperature, humidity, light and oxygen of the air cause chemical reactions in food, such as fat rancidity.

The more nutritious the food, the faster it will go rancid if stored in an improper environment.

As for the online rumors that soy milk is prone to spoilage, such as "sour taste after opening" and "turning into tofu pudding after being left for a while", it is speculated that these are the result of excessive growth of microorganisms. The more nutritious the food is, the easier it is for microorganisms to grow. Soy milk, which is rich in plant protein, is a breeding ground for microorganisms and will become rancid very quickly if stored in an improper environment.

Past studies have found that most bacteria can multiply rapidly at 15.5-47 degrees Celsius. Therefore, if food is left at room temperature for more than 1-2 hours, the number of bacteria will double rapidly.

Consumers should pay attention to antibacterial management and the storage environment of soy milk after purchase

There are many factors that cause soy milk to go rancid. In addition to the industry's antibacterial management in the production process, consumers should also pay attention to the storage environment of soy milk after purchase. Otherwise, even soy milk with good quality control may accelerate the rate of rancidity due to high temperature, bacterial contamination after opening, etc.

If people accidentally consume sour soy milk, it may cause health hazards. Therefore, controlling the number of colonies during the production process and maintaining a proper storage environment are the two key points to prevent soy milk from becoming sour and ensure drinking safety. If non-accidental cases of soy milk product deterioration are found, the production process should be reviewed and controlled. In addition, the speed of sourness and odor should not be used as a criterion for judging the freshness of soy milk and the addition of preservatives.