An overlooked source of salt: mustard tuber

Salt is the most important condiment in life. In recent years, people have paid more and more attention to health, and more and more people have begun to realize the importance of low salt intake. Even the "China Healthy Pickled mustard tuber Green Book" shows that salt reduction and health have become important indicators for consumers to choose pickled mustard tubers. At the same time, many pickled mustard tuber brands focus on low-salt pickled mustard tubers. Salt reduction and health have become a new development direction for the pickled mustard tuber industry.

I have to say, this is a good thing. The trend of "reducing salt" has finally reached the easily overlooked field of pickled mustard tuber. Today, I would like to take this opportunity to talk about reducing salt.

01. Reducing salt intake is an inevitable trend for health

As the most important condiment among all flavors, salt is not only a condiment, but also necessary for the body's metabolism. The sodium ions in salt are the basic components of our cells. Cells have evolved special sodium ion channels to transport sodium ions. Such flow brings about changes in cell potential and forms various signals. Therefore, we need to consume salt on a daily basis.

However, too much salt is not good. When salt intake is too high, it may pose a threat to health, such as high blood pressure. High blood pressure and salt intake are highly correlated. If it is not controlled in time, it may also increase the risk of cardiovascular and cerebrovascular diseases.

Therefore, over the years, both China and foreign countries have been advocating salt reduction. For example, my country's National Health Commission has put forward recommendations for salt reduction: it is recommended that the average daily salt intake per person is 5g.

In fact, the country has been promoting salt reduction for many years, but due to our long-term eating habits, our salt intake is still very high. For example, the "Report on the Nutrition and Chronic Disease Status of Chinese Residents (2020)" shows that in 2019, Chinese families used 9.3g of salt for cooking every day.

Therefore, there is still a long way to go to reduce salt intake.

Some people may say, we already pay great attention to reducing salt in our daily lives, and our meals are very light, but why are there still high salt levels?

Here we have to mention an easily overlooked high-salt food, which may be one of the important factors of high salt content: pickled mustard tuber.

02. “High-salt” mustard tuber, an easily overlooked daily life

Zhacai can be said to be a traditional food in our country. Since ancient times, the diligent and wise ancient people have explored many ways to store food. Finally, pickled food with salt as the basic operation was born. Of course, new delicious food was born from this. Zhacai, as the most basic original ecological food, is naturally also a representative of pickled food.

Thousands of years of habit have made pickled mustard tuber one of the basic foods in our daily life today. For example, a survey shows that as many as 43.7% of people eat pickled mustard tuber more than three times a week, and as many as 27.2% eat it 1-2 times a week, which means that more than 70% of people eat pickled mustard tuber at least once a week.

The basic process of pickled mustard tuber is salt pickling, which results in a very high salt content. As a result, some people may pay attention to reducing salt in their main diet, but because of the high salt content of pickled mustard tuber, their total salt intake eventually exceeds the standard.

On one hand, there is delicious mustard tuber, and on the other hand, there is the pressure of reducing salt. Is it really impossible to solve this problem? Let's take a systematic look at how to reduce the salt content of mustard tuber.

03. Why can’t pickled mustard tuber be separated from salt?

To reduce the amount of salt in mustard tuber, we must first understand why mustard tuber cannot do without salt. The answer has two aspects.

1. Flavor. We must consume salt in our daily life. This is necessary for health because our metabolism cannot do without salt. After long-term adaptation, we also have a demand for the flavor of food, so salt has become a basic food additive (of course, our food itself also contains sodium ions, so it is not necessary to add additional salt)

2. Preservation. As we mentioned earlier, pickling food is actually a very old practice, which is people’s solution to the problem of food spoilage and storage.

The reason why food spoils is essentially due to the influence of microorganisms. Microorganisms are everywhere, in the air, in the soil, and in the water. People cannot completely eliminate microorganisms, so these microorganisms will multiply on food as long as they have the opportunity, resulting in food corruption.

Salt, as a water-soluble compound, can quickly dehydrate and kill microorganisms, thereby allowing food to be better preserved.

In fact, salt is a necessary ingredient not only for pickled mustard tuber, but also for pickled meat and bacon.

04. How to reduce the salt content of pickled mustard tuber?

Now that we know why pickled mustard tuber cannot do without salt, we have a direction to reduce the salt content in it. As long as the problems of flavor and preservation are solved, the demand for salt can actually be reduced to a certain extent.

The flavor problem is actually easy to solve because we have seasonings. We have developed many spices such as peppercorns, chili peppers, and star anise. These materials are flavor substances themselves, so they can make food more flavorful. Therefore, through these spices, the demand for salt can be reduced.

So, the second question is, can the salt be reduced appropriately? This involves the issue of microbial fermentation.

Generally, pickled mustard tubers need to be kept at room temperature, which is often suitable for the reproduction of microorganisms. In order to inhibit the fermentation of microorganisms, we must use high concentrations of salt to prevent the ingredients from spoiling.

So how do we reduce the growth of microorganisms? The answer is to adjust the conditions that microorganisms must rely on. Microbial fermentation is very sensitive to temperature. For example, in the laboratory, a common way to inhibit the development of microbial strains is to reduce their growth by low temperature.

Therefore, low temperature can be used to inhibit the growth of microorganisms. After solving the need for salt in the pickling process, there is another problem that needs to be solved, that is, the problem of preservation after pickling. Because microorganisms are everywhere, basically all foods need to solve a problem: preservation.

Zhacai is no exception. Using low salt can solve the problem of corruption during the pickling process, but what about corruption during daily storage? The most common strategy is to use various preservatives. Basically, all kinds of food sold currently contain preservatives. However, many people are somewhat worried about preservatives. After all, large amounts of these ingredients have a certain impact on health.

So, is it possible to do without preservatives? In fact, there is a way. The milk pasteurization method that we are familiar with in daily life is such a process. Pasteurization is a sterilization technology developed by Pasteur, the founder of microbiology. It uses relatively low temperature (62-65℃) sterilization for about half an hour, which can basically eliminate various bacteria. In the 150 years since the birth of pasteurization, it has become one of the basic sterilization strategies in the milk industry.

Since milk can be pasteurized, pickled mustard tuber is no exception. Through pasteurization, microorganisms can be effectively eliminated, and there is no need to use preservatives.

If the salt demand for sterilization during the pickling process and storage is solved, the salt demand in the mustard tuber will drop sharply. Then, we can further reduce the salt content in the mustard tuber to make it even saltier.

Here we have to mention the desalination technology of the leading domestic pickled mustard tuber. They adopt a three-stage linear desalination process to gradually reduce the salt content in the pickled mustard tuber. At the same time, they use high-precision salinity sensors and salinity big data analysis software, combined with intelligent control technology to accurately control the salt in the pickled mustard tuber. Finally, they can ensure that the salt content in the pickled mustard tuber is very low when it leaves the factory.

We can see that pickled food such as mustard tuber, which is traditionally believed to require high salt, does not seem to be so necessary. By scientifically analyzing the effect of salt on pickled food, we can make corresponding strategies, as shown in the figure below.

It can quickly reduce the salt content in the pickled mustard tuber, greatly reducing the salt content in the pickled mustard tuber while maintaining the flavor and freshness, and is also more conducive to salt reduction control.

Of course, the salt reduction campaign is not just about eating pickled mustard tubers. We need to further reduce the salt in our daily food intake so that we can stay away from cardiovascular diseases and live a healthier life.