Some people can't cook without soy sauce. It not only adds color to dishes but also enhances their flavor. Soy sauce is divided into cooking soy sauce and table soy sauce, but many people don't pay much attention to the type they buy when shopping. It's common for a household to only have one kind, using it for both stir-fries and cold dishes, which can easily pose health hazards.
Cooking soy sauce is generally divided into two types: flavor-oriented and health-oriented. The former includes soy sauces like wheat fragrance soy sauce, aged soy sauce, and Beijing light soy sauce king. The latter includes salt-free soy sauce (which contains no sodium but has a certain salty taste, suitable for kidney patients), iron-fortified soy sauce, and iodized soy sauce. During the production, storage, transportation, and sales of these soy sauces, contamination due to poor hygiene conditions is inevitable, and they may even mix with pathogenic bacteria that cause intestinal infectious diseases. Furthermore, the microbial index requirements for them during testing are relatively low, so it's not uncommon for a bottle of qualified soy sauce to contain a small amount of bacteria.
Experiments have shown that Shigella can survive in soy sauce for 2 days, while Paratyphoid bacillus, Salmonella, and pathogenic Escherichia coli can survive for 23 days. Typhoid bacillus can survive for 29 days. Other research has found that there is a halophilic bacteria in soy sauce that can generally survive for 47 days. Once a person consumes soy sauce containing halophilic bacteria, they may experience symptoms such as nausea, vomiting, abdominal pain, and diarrhea. In severe cases, it can lead to dehydration, shock, and even be life-threatening. Although this situation is relatively rare, for safety reasons, it is best to consume soy sauce after cooking, as heating can generally kill these bacteria.
If you want to make cold dishes, it is best to choose table soy sauce. The microbial index requirements for table soy sauce are stricter than for cooking soy sauce. National standards stipulate that the total number of bacterial colonies detected per milliliter of soy sauce for table and cold dishes must not exceed 30,000, so it is not harmful to health even when consumed raw.
Although soy sauce is highly nutritious, containing up to 17 amino acids, various B vitamins, and a certain amount of calcium, phosphorus, iron, and other minerals, its salt content is relatively high, so it should not be consumed excessively in daily life. The salt content of soy sauce is as high as 18%-20%, meaning that about 1 gram of salt is in every 5 milliliters of soy sauce. Besides for seasoning, it is mainly added to prevent the soy sauce from spoiling and deteriorating. People with diseases such as hypertension, kidney disease, pregnancy edema, liver cirrhosis with ascites, or heart failure should be especially cautious when consuming it, as it can lead to a worsening of their condition.
In clinical practice, people often ask whether eating soy sauce after a skin injury will cause the wound to turn dark and leave a scar. In fact, this concern is completely unnecessary. Whether a scar is left on the skin mainly depends on the depth of the injury, the degree of bacterial infection, and individual differences. The main component of soy sauce is glutamic acid, which has no direct relationship with tissue repair. The pigments in it are food colorings, which are not transported to the skin after being ingested. Therefore, people who have been injured or have undergone cosmetic surgery do not need to avoid eating soy sauce.