Fortification of niboshi with histidine prepared from katsuobushi protein digest

Free and total histidine contents in the muscle of various fishes and invertebrates caught in the Seto Inland Sea were estimated. These contents were higher in the muscles from skipjack, yellowfin tuna, yellowtail and mackerel than in those from lizard fish, sea bream and hairtail. Invertebrate muscles, except squid, contained low free and total histidine. Boiled and dried anchovy (niboshi) contained lower free histidine than that of dried anchovy (suboshi). To prepare free histidine‐rich extracts, the waste residue of soup stock from smoke‐dried and shaved skipjack (katsuobushi) was digested with proteases. The extract of the enzyme digest contained high free histidine and was used to fortify niboshi with free histidine. If taken, the fortified niboshi may suppress food intake, and prevent obesity.