【Reading】いのしんさん

【English Name】Inosinic Acid

Inosinic acid (IMP) is a compound belonging to the nucleotides that produce umami. It is an organic compound with hypoxanthine, D-ribose and phosphoric acid as its framework, abundantly present in meat and seafood.

In sushi culture, it is an indispensable presence as the central component responsible for the umami of katsuobushi (dried bonito). The sodium salt of inosinic acid is widely used as a nucleotide-based umami seasoning, and in industrial production it is enzymatically synthesized using yeast-derived RNA as the starting material.

It is often said that soft water is suited to dashi extraction, but in comparative experiments conducted while varying water hardness, there are reports that hard water actually increased the extracted amount. However, in sensory evaluations asking about palatability, no significant difference due to differences in hardness was confirmed.

It is a widely known phenomenon that combining it with glutamic acid, abundant in kelp dashi, synergistically enhances umami. In sushi, a composition is established in which shari (vinegared rice) made with kelp dashi unites with the inosinic acid possessed by seafood toppings, cited as a fine example that naturally draws out this synergistic effect.