Soy fermentation

In addition to tempeh, there are many soy products that are the result of fermentation, such as natto, miso, shoyu (soy sauce), and oncom.

Natto

Natto has been a traditional Japanese food for more than a thousand years. Natto is soybeans fermented by Bacillus subtilus natto bacteria. Natto has an ammonia odor as a result of the breakdown of amino acids by Bacillus subtilis natto. The fermentation of natto produces viscous and sticky polymers (polyglutamic acid) that make natto very slimy. Because of this odor and appearance, natto is no longer as popular. During natto fermentation, Bacillus subtilus natto produces enzymes, vitamins, amino acids, and other nutrients that are unique to natto. Some of the beneficial effects of natto include the prevention of heart attacks, cancer, osteoporosis, and intestinal infections. Natto bacteria have a powerful enzyme that can dissolve blood clots.

Miso

Miso is another traditional Japanese fermented soy product. Miso is made from koji mixed with rice, barley or soybeans. The miso is fermented and aged in wooden barrels. The lighter and sweeter types of miso are fermented and aged for only one to two months. The darker types of miso can be aged for up to 2 years and have a strong and salty taste. The Japanese drink a cup of miso soup every morning, which is known to have a health-promoting effect.

Shoyu ( soy sauce)

Shoyu, or soy sauce, is a salty, brown liquid obtained from a long fermentation of a mixture of soybeans and wheat. First, the soybeans and wheat are mixed with a starter culture (Aspergillus oryzae). The mixture is then left to ferment for a few days in large perforated vats. This culture, called koji, is then transferred to fermentation tanks where salt and water are added. This mash, called moroni, is left to ferment for another 6 months. After this period, the mash is pressed to extract the shoyu. During the fermentation of soy sauce, enzymes produced by the mold break down the soy proteins. As a result, most naturally fermented soy sauces contain no detectable levels of gluten (<5 ppm) and can be considered gluten-free. The flavor and color of shoyu depends on the salt concentration, fermentation temperature, and fermentation time. Shoyu is very popular in Asian countries such as Japan and China. A major brand of naturally fermented shoyu is Kikkoman.

Oncom

Along with tempeh, oncom is one of the traditional staples of West Javanese cuisine. There are two types of oncom: black oncom and red oncom. Black oncom is actually tempeh, but made from by-products such as okara or peanut press cake instead of whole soybeans. But red oncom is unique in that it is fermented with Neurospora. It is the only human food produced from Neurospora. In Europe, the production and sale of red oncom is illegal because it is considered a novel food. Novel food is defined as food that has not been consumed by humans to a significant degree in the EU before 1997, when the first novel food regulation came into force. To date, no food product fermented with Neurospora has been approved.