Abstract
We examined the effects of ingredients and boiling time on the quality of Nikogori.
The boiling time for making the firmest gel with yellowtail and Pacific cod was shorter than that with chicken wings. The firmest Nikogori was that formed from chicken wings, being firmer than that from yellowtail, while the gelling of broth from Pacific cod was very poor.
Gel made from chicken wings was relatively stable during long-term boiling. However, those from yellowtail and Pacific cod gradually became soft by boiling for more than 30 minutes.
The transparency of the broth decreased with increasing boiling time, and the amount of protein in the broth increased with yellowtail and chicken wings.
Proteins in the broth contained the gelatinous molecules forming Nikogori, as well as unidentified proteins hindering the gelation process.
The gelatinous molecules in the broth were changed to those of low molecular weight by long-term boiling so that the Nikogori became soft.
