katsuobushi (smoked-dried bonito)
ingredient / ingredient-katsuobushi
鰹節 / Katsuwonus pelamis
Katsuobushi (smoked-dried bonito) is a Japanese preserved food and dashi ingredient made by repeatedly smoking and drying bonito after boiling.
On this page (7 sections)
Reading the bitterness
Katsuobushi is a Japanese preserved food made by boiling bonito and repeatedly smoking and drying it, and is used as a dashi ingredient. In a study that extracted arabushi with supercritical carbon dioxide and examined high aroma-contribution constituents by aroma extract dilution analysis (AEDA), guaiacol (2-methoxyphenol) was identified as the constituent with the highest aroma contribution, with an FD factor of 15625 and concentration of 9.12 ppm. In the same extract, syringol (2,6-dimethoxyphenol) had the highest concentration, 256 ppm, but its FD factor was only 3125, so high concentration did not necessarily coincide with high aroma contribution. This study was limited to aroma evaluation and did not measure taste, including bitterness.
Adding katsuobushi (shaved flakes) to raw and cooked bitter gourd is reported to have lowered bitterness in both states. The authors interpret this debittering effect as katsuobushi adsorbing the bitter substances of bitter gourd.
In an experiment adding katsuobushi stock (liquid simmered in hot water) to bitter gourd extract, bitterness also dropped (p<0.05), but it did not reach the large drop seen when katsuobushi itself was added. The authors think debittering mainly involves adsorption by the solid katsuobushi rather than components dissolved into the liquid.
Sources for this overview
Aroma Compounds Contributing to Dried Bonito（かつお節の香りに寄与する重要香気成分）
Checked for this overview: Used the AEDA analysis result in which guaiacol had the highest aroma contribution. / Used the contrast in which syringol had the highest concentration but lower aroma contribution.
Reduction of Bitterness of the Bitter Gourd by Katsuobushi
Checked for this overview: Used the report that adding katsuobushi reduced bitterness in both raw and cooked bitter gourd. / Used the report that stock also lowered bitterness, but not as much as the flakes
Follow the connections
katsuobushi (smoked-dried bonito) →contains→ guaiacol
syringol →occurs in→ katsuobushi (smoked-dried bonito)
bitter melon →— perceived bitterness is s…→ katsuobushi (smoked-dried bonito)
Hypotheses and recipe candidates for this entry are on the Japanese page.
Structured claims — open a section to read each claim's confidence, evidence and limits
Composition and content (2)
Scope: Supercritical CO2-extracted raw bonito flake katsuobushi, with the top 10 components by aroma contribution selected by AEDA (Aroma Extract Dilution Analysis) method
Note: Guaiacol (2-methoxyphenol) was identified with FD (Flavor Dilution) factor 15625 and concentration 9.12 ppm as the component with the highest aroma contribution. In the same extract, syringol (2,6-dimethoxyphenol) showed the highest concentration at 256 ppm but an FD factor of only 3125, exemplifying that aroma 「強さ(濃度)」 (in translation: "intensity (concentration)") and 「寄与度(希釈感度)」 (in translation: "sensory contribution (dilution sensitivity)") do not correspond. Evaluation was performed by GC-MS/olfactometry and orthronasal sensory evaluation by a professional chef, both limited to aroma (olfactory) assessment. Reference to or measurement of taste characteristics including bitterness is not found in the original text.
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ingredient-katsuobushi —contains→ compound-guaiacolScope: Same as above (supercritical carbon-dioxide extract of katsuobushi arabushi)
Note: 2,6-dimethoxyphenol (syringol) had the highest concentration (256ppm) among the 10 important aroma constituents identified. However, this study evaluated aroma only, and no connection to taste (bitterness) has been confirmed.
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compound-syringol —occurs_in→ ingredient-katsuobushiHow processing and cooking change it (2)
Scope: Layer: food. Katsuobushi added to raw bitter gourd and to cooked bitter gourd.
Note: Based on the abstract's description (the Japanese portion of the body text was garbled due to a font-embedding problem in the PDF, so specific figures such as sensory scores could not be confirmed). The authors conclude that katsuobushi has a debittering effect by adsorbing (binding) the bitter substances.
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ingredient-bitter-gourd —has_perceived_bitterness_suppressed_by→ ingredient-katsuobushiScope: Layer: food. Katsuobushi 'extract' added to bitter gourd (a condition without solid material).
Note: The authors interpret that debittering is due mainly to adsorption (binding) by the solid material rather than to components dissolved into the extract. 2026-09-26: Reread in full (Figure 2, p.187). The English abstract's phrase "significant debittering effect was not achieved by using the extract" means 「かつお節と同程度の著しい効果は得られなかった」 (in translation: "an effect as pronounced as with katsuobushi itself was not obtained"), and in Figure 2 there is a significant (p<0.05) decrease with the extract addition.
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ingredient-bitter-gourd —has_perceived_bitterness_unchanged_by→ ingredient-katsuobushi