Irú is a type of fermented locust beans used as a condiment in cooking. It is similar to ogiri and douchi. It is very popular among the Yoruba people of Nigeria. It is used in cooking soups like egusi soup and ogbono soup.
It can be found fresh or dried. The fresh variety is usually wrapped in moimoi leaves, which are similar in appearance and texture to banana leaves. It has a pungent smell.
The dried variety is flattened into discs or cakes for sale. Dried iru is weaker in flavor and pungency than fresh (though frying dried iru in cooking oil will restore much of the flavor). The dried variety stores very well in freezers.
In the fermentation, the reducing sugar content increases, and the total free amino acid content decreases initially, however in the end there is a large increase in free amino acid content.[1]