Soybean allergens in different Japanese miso pastes
What it found
In lab tests, all miso pastes tested had lower levels of major soybean allergens than soybean extract.
Darker misos fermented for longer had the lowest levels.
What they found
Studies in people
Patient IgE binding
When tested with blood serum from three soybean allergy patients, all miso samples bound less IgE than soybean extract. The darker misos bound the least.
Animal and lab studies
Protein breakdown
The main protein bands in soybean extract were missing from all miso samples. Instead, miso had smaller protein fragments around 10 to 25 kDa, which are likely pieces of broken-down soy proteins.
Allergen levels lower
For three allergens (Gly m Bd 30K, Gly m Bd 28K, and 7S globulin), levels in all misos were less than 20% of those in soybean extract. Some misos had less than 10%.
Some allergens remain
Trypsin inhibitor, Gly m 4, and Gly m 3 stayed at higher levels in some light-colored misos, up to 80% of soybean extract levels. These allergens may resist breakdown during short fermentation.
Dark miso lowest
Mame-miso and dark Karakuti-kome misos, which are fermented for 3 months to 2 years, had the lowest allergen levels. Mame-miso had less than 10% for all allergens tested.
How it was done
Miso is made from soybeans, which can cause allergic reactions in some people. The authors wanted to see if fermentation reduces the allergen levels in different types of miso.
They extracted proteins from 10 miso pastes made in Japan (Amakuti-kome, Karakuti-kome, Mugi-miso, Mame-miso) and from soybean extract. They measured six major soybean allergens using specific antibodies and also tested how much IgE from three soybean allergy patients bound to the miso proteins.
What it can’t tell you
- This study used lab tests and blood serum from only three allergy patients. It cannot show whether eating these misos would cause allergic reactions in people.
- The authors say that further allergenic risk assessments and clinical challenge tests are needed to clarify the effects of fermentation time on miso allergenicity.
The paper
- Title
- Hypoallergenicity of various miso pastes manufactured in Japan
- Type
- Study
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Moriyama T, Yano E, Suemori Y, Nakano K, Zaima N, Kawamura Y (2013). Hypoallergenicity of various miso pastes manufactured in Japan. Journal of nutritional science and vitaminology. doi:10.3177/jnsv.59.462Free full textPubMed 24418881DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error