Soy protein has been shown to support health needs across the lifespan as a source of lean, cholesterol-free and lactose-free protein. The field of nutrition science and exercise physiology supports the need for physical activity in combination with more nutritious choices—such as consuming sources of soy protein, to maintain a healthy quality of life.
Soy sauce is a very flavorful ingredient made from fermented soybeans and wheat.It originated in China and has been used in cooking for over 1,000 years.Today, it’s one of the best-known worldwide. It is a staple ingredient in many Asian countries and used widely across the rest of the world.The way it's produced can vary significantly, causing significant changes in flavor and texture, as well as health risks.This article investigates how soy sauce is produced and its potential health risks and benefits. Soy sauce is a salty liquid condiment traditionally produced by fermenting soybeans and wheat.It is thought to have originated from a Chinese product called “chiang ” over 3,000 years ago. Similar products were developed in Japan, Korea, Indonesia and across Southeast Asia.It first came to Europe in the 1600s through Dutch and Japanese trading (, ).The word “soy” comes from the Japanese word for soy sauce, “shoyu.” In fact, the soybean itself was named from soy sauce.The four basic ingredients in soy sauce are soybeans, wheat, salt and fermenting agents like mold or yeast.Regional varieties of soy sauce may have varying amounts of these ingredients, resulting in different colors and flavors. Summary Soy sauce is a salty condiment produced through the fermentation of soybeans and wheat.
It originated in China and is now produced in many Asian countries. Many different types of soy sauce are available. They can be grouped based on their production methods, regional variations, color and taste differences.
Traditional ProductionTraditional soy sauce is made by soaking soybeans in water and roasting and crushing the wheat. Then the soybeans and wheat are mixed with a culturing mold, most commonly Aspergillus, and left for two to three days to develop.Next, water and salt are added, and the entire mixture is left in a fermenting tank for five to eight months, though some types may age longer.During fermentation, enzymes from the mold act on the soy and wheat proteins, gradually breaking them down into amino acids. The starches are converted to simple sugars, then fermented to lactic acid and alcohol.After the aging process is complete, the mixture is laid out onto cloth and pressed to release the liquid. This liquid is then pasteurized to kill any bacteria.
Finally, it’s bottled (, ).High-quality soy sauce uses only natural fermentation. These varieties are often labeled “naturally brewed.” The ingredients list will usually only contain water, wheat, soy and salt. Summary Traditional soy sauce is made with a mixture of soybeans, roasted wheat, mold and salt water, which is aged for five to eight months. The resulting mash is then pressed, and the soy sauce liquid is pasteurized and bottled. Chemical productionChemical production is a much faster and cheaper method of making soy sauce. This method is known as acid hydrolysis, and it can produce soy sauce in a few days instead of many months.In this process, soybeans are heated to 176°F (80°C) and mixed with hydrochloric acid. This process breaks down the proteins in the soybeans and wheat.However, the resulting product is less attractive in terms of taste and aroma, since many substances produced during traditional fermentation are missing.
![Soy sauce production process Soy sauce production process](/uploads/1/2/5/5/125583489/951704781.png)
Therefore, extra color, flavor and salt are added.Additionally, this process produces some undesirable compounds that are not present in naturally fermented soy sauce, including some carcinogens.In Japan, soy sauce that is brewed in a purely chemical process is not considered soy sauce and cannot be labeled as such. However, it may be mixed with traditional soy sauce to lower costs.In other countries, chemically produced soy sauce may be sold as-is. This is often the type of soy sauce you’ll find in the small packets given with take-away meals.The label will list “hydrolyzed soy protein” or “hydrolyzed vegetable protein” if it contains chemically produced soy sauce.
Summary Chemically manufactured soy sauce is made by hydrolyzing soy proteins with acid and heat. This method is quick and cheap, but the resulting soy sauce tastes inferior, contains some toxic compounds and may require extra colors and flavors. Regional DifferencesIn Japan there are many different types of soy sauce. Dark soy sauce: Also known as “koikuchi shoyu,” this is the most common type sold in Japan and overseas. It’s reddish brown and has a strong aroma (, ). Light soy sauce: Also called “usukuchi,” this is made from more soybeans and less wheat, and it has a lighter appearance and milder aroma (, ). Tamari: Made from mostly soybeans with 10% or less wheat, it lacks aroma and is darker in color (, ).
Shiro: Made almost only with wheat and very few soybeans, it's very light in color. Saishikomi: Made by breaking down the soybeans and wheat with enzymes in a solution of unheated soy sauce instead of salt water. It has a heavier taste, and many enjoy it as a dipping sauce (, ).In China, the tamari-style soybean-only soy sauce is the most common type.However, today a more modern production method is most common. Soybean meal and wheat bran are fermented for just three weeks instead of several months. This method results in a very different flavor compared to traditionally produced soy sauce (, ).Chinese soy sauces are often listed as “dark” or “light” in English.
Dark soy sauce is thicker, older and sweeter and used in cooking. Light soy sauce is thinner, younger and saltier, and it's more often used in dipping sauces.In Korea, the most common type of soy sauce is similar to the dark koikuchi type in Japan.However, there is also a traditional Korean soy sauce called hansik ganjang. It’s made only from soybeans and mainly used in soup and vegetable dishes.In Southeast Asian countries like Indonesia, Malaysia, the Philippines, Singapore and Thailand, the tamari-style sauce is most commonly produced, but many local variations exist.Other varieties include sauces thickened with sugar, such as kecap manis in Indonesia, or those with additional flavors added, such as shrimp soy sauce in China. Summary There is a great variety of soy sauces across Asia, each with different ingredients, flavors and aromas. The most common type is Japanese dark soy, called koikuchi shoyu, which is made from naturally fermented wheat and soybeans. Below is the nutritional breakdown for 1 tablespoon (15 ml) of traditionally fermented soy sauce. Calories: 8.
Carbohydrates: 1 gram. Fat: 0 grams.
Protein: 1 gram. Sodium: 902 mgThis makes it high in salt, providing 38% of the Recommended Daily Intake (RDI).
Health concerns are often raised regarding soy sauce, including its salt content, presence of cancer-causing compounds and specific reactions to components like MSG and amines. Research on soy sauce and its components has found some potential health benefits, including:. May reduce allergies: 76 patients with seasonal allergies took 600 mg of a soy sauce component per day and showed improved symptoms.
The amount they consumed corresponds to 60 ml of soy sauce per day (, ). Promotes digestion: A soy sauce broth was given to 15 people, resulting in increased stomach juice secretion, similar to the levels that can occur after ingesting caffeine. Increased stomach juice secretion is thought to help digestion ( ). Gut health: Some isolated sugars in soy sauce have been found to have a positive prebiotic effect on certain types of bacteria found in the gut. This could be beneficial for gut health.
Source of antioxidants: Dark soy sauce has been found to contain several strong antioxidants. It is unclear what the benefits may be in humans, though one study found positive effects on heart health (, ).
Could promote the immune system: Two studies found that giving mice polysaccharides, a type of carbohydrate found in soy sauce, improved immune system responses (, ). May have anticancer effects: Multiple experiments on mice have shown soy sauce may have cancer- and tumor-inhibiting effects. More research is needed to see if these effects are also present in humans (, ). May reduce blood pressure: Some varieties of soy sauce, such as salt-reduced or Korean ganjang, have been found to decrease blood pressure in mice. Studies in humans are still needed (, ).It should be noted that much of this research has only been done in animals or very small studies in people and used large doses of soy sauce or its components.Therefore, while some of these results sound promising, it is too early to say whether soy sauce can contribute truly significant health benefits when it’s consumed at the level found in the average diet. Summary Research on soy sauce has found promising potential health benefits, including for the immune system, gut health, cancer and blood pressure. However, since most studies have used animals or small sample sizes, more research in humans is needed.
Soy sauce is a flavorful condiment that is used in a wide variety of dishes and cuisines.It can be produced through natural fermentation or chemical hydrolysis. Each production method leads to quite different flavor and health profiles.Eating soy sauce may involve some health risks. However, the worst of these are associated with chemically produced varieties and can be avoided by using naturally fermented soy sauce.Soy sauce may also have some health benefits, but more research is needed to confirm whether they apply to humans.Overall, like most foods, soy sauce can be enjoyed in moderation as part of a healthy diet.