Can I eat fermented bean curd that has been stored for four years?

The general shelf life of fermented bean curd is one year. Fermented bean curd that has been stored for four years cannot be eaten because it has deteriorated after four years. If it is consumed at this time, it will affect gastrointestinal digestion and cause diarrhea, so any expired food should not be eaten. Now let us understand the benefits of eating some tofu in daily life, especially for those who like to eat fermented bean curd.

The efficacy and function of fermented tofu

Fermented tofu is a soy product made from soybeans through microbial fermentation. Through fermentation, the original bean smell, flatulence factors and anti-nutritional factors of soybeans are removed, and a variety of alcohols, esters, organic acids and amino acids with delicious taste and fragrance are produced. Compared with soybeans, fermented tofu has the following advantages:

1. Helps control blood pressure

The protein is converted into peptides and amino acids that are easier to digest and taste better. Among these peptides, there are also some active peptides that are beneficial for controlling blood pressure, because studies have found that they can inhibit the activity of angiotensin converting enzyme (ACE) I.

2. Better absorption of minerals

Not only do minerals such as calcium, magnesium, and iron not decrease, their bioavailability will also increase. This is because soybeans originally contain a lot of phytic acid, which greatly hinders the absorption of minerals. However, during fermentation, mold has already destroyed these phytic acids.

3. Increased isoflavone activity

Soy isoflavones are a mixture of polyphenols with antioxidant activity. They can prevent and inhibit leukemia and have anti-tumor effects, especially for the prevention and treatment of breast cancer and prostate cancer. Studies have shown that the isoflavone content of soybeans will decrease after washing, but fermentation does not affect its content and can change the types of isoflavones.

In unfermented soy products, isoflavones mainly exist in the form of flavonoid glucosides. After fermentation, the glycosides are hydrolyzed in large quantities by the hydrolytic enzymes of fungi in fermented tofu, turning them into free isoflavone aglycones. The free aglycones have broader and stronger antibacterial, antioxidant and estrogen-like activities. These glycogens have good solubility, low viscosity, and resistance to gel formation, and can be effectively absorbed by the intestine.

4. Lowers Cholesterol

The fat in fermented tofu is unsaturated fatty acid, and it does not contain cholesterol. A large number of experimental studies have shown that the hydrophobic protein components in fermented tofu can combine with bile acid, reducing the absorption of cholesterol and the reabsorption of bile acid in animals. Many research results on animals and humans have also confirmed that this protein has the effect of lowering cholesterol, so it is healthier than cheese containing high cholesterol.

5. Easier to Digest

Those components that hinder protein digestion are also eliminated by mold.

6. No bloating

Many people feel intestinal bloating after eating soybeans. This is because soybeans contain bloating factors, namely glycosides such as raffinose and stachyose. After fermentation by microorganisms, these flatulence factors are broken down in fermented tofu.

7. Improved protein utilization

The protein contained in soybeans is difficult to digest and absorb, but after being hydrolyzed by microbial enzymes, a low-molecular polypeptide mixture is generated, which is easy to digest and absorb, increasing the digestibility of protein in fermented tofu from 65.3% of soybeans to 96%. Studies have shown that the amount and performance of protein in fermented tofu are comparable to those of animal foods, and it does not contain cholesterol. Therefore, fermented tofu is a healthy food containing high protein.

8. Increased B vitamins

Due to the action of microorganisms, the content of vitamin B2 produced in fermented tofu is second only to dairy products and 6 to 7 times higher than tofu; the amount of vitamin B12 is second only to animal liver. For vegetarians, eating fermented tofu regularly can prevent pernicious anemia and senile dementia; the content of vitamin B1 and niacin (also known as nicotinic acid) is also higher than that of ordinary foods.

What is the shelf life of fermented tofu?

▷ Use dry chopsticks to pick up fermented bean curd

Every time you eat, use clean chopsticks to pick it out first. Do not put the uneaten food back into the bottle to avoid the production of nitrite.

▷ Low temperature storage

Unfinished fermented bean curd should be stored in the refrigerator.

▷ Do not pour out the soup in the fermented bean curd

Do not pour out the fermented bean curd juice before finishing eating. The fermented bean curd juice can prevent it from spoiling. The leftover fermented bean curd juice can be used to cook dishes, such as: fermented bean curd with water spinach, fermented bean curd with braised pork, etc.

Different brands, different quality, different shelf life, you can look at the packaging,

The opened fermented bean curd can be kept in the refrigerator for about half a year. Generally, there is a shelf life on the packaging bottle of fermented tofu that you buy, and you can eat it according to the shelf life, but many people will pour a layer of oil or white wine on the fermented tofu after opening it. The taste will get better and better as it is kept for a long time, because it can isolate the air and keep it for a longer time.

Fermented tofu should be sealed and stored in a cool and dry place.

When picking up tofu, use clean and dry chopsticks to avoid water or other debris entering the bottle.

The opened bean curd should be placed in the refrigerator so that it can be preserved for a long time.