the library

Koji

Savory & ferment· ferment vinegar

Every one of its 15 compounds carries a paper the library can cite.

• acetaldehydearomaaldehydereads as pungent, fruity odor (PubChem)Measured in 18 of 338 ingredients.cite

  8.92 and 12.02 ppm in rice koji against 0.44 ppm in unfermented rice — a twentyfold rise, and the lowest fold-change of anything admitted here, so it is the compound in this profile most partly inherited from the substrate — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Aldehyde block, row 'Acetaldehyde', columns AO_RIB40_R1 and AO_RIB40_R2)
• ethanolaromaalcoholreads as burning (PubChem)Measured in 19 of 338 ingredients.cite

  2798.91 and 4449.95 ppm in rice koji against 109.38 ppm in the unfermented steamed rice — the largest volatile in the table by two orders of magnitude, and roughly threefold higher than either Aspergillus flavus strain reached — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1 (Volatile compounds quantification (parts per million) across unfermented rice (negative control), and rice fermented by AO_RIB40, AF_NPK13tox, and AF_AflaGuard), Alcohol block, row 'Ethanol', columns AO_RIB40_R1 and AO_RIB40_R2)
• phenylacetaldehydearomaaldehydeMeasured in 21 of 338 ingredients.cite

  20.96 and 14.63 ppm in rice koji against 0 ppm in unfermented rice — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Aldehyde block, row 'Benzeneacetaldehyde', columns AO_RIB40_R1 and AO_RIB40_R2)
• 1-propanolaromaalcoholreads as burning taste (PubChem)Measured in 22 of 338 ingredients.cite

  41.44 and 42.90 ppm in rice koji against 0.43 ppm in unfermented rice — the most reproducible of the major alcohols, the two replicates agreeing to within 4% — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Alcohol block, row 'Propanol', columns AO_RIB40_R1 and AO_RIB40_R2)
• isopropyl alcoholaromaalcoholreads as burning taste (PubChem)Measured in 2 of 338 ingredients.cite

  10.97 and 10.94 ppm in rice koji against 0 ppm in unfermented rice; the two replicates agree to within 0.3% — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Alcohol block, row 'Isopropyl Alcohol', columns AO_RIB40_R1 and AO_RIB40_R2)
• isobutanolaromaalcoholreads as sweet, musty odor (PubChem)Measured in 24 of 338 ingredients.cite

  217.53 and 307.81 ppm in rice koji against 0.76 ppm in unfermented rice — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Alcohol block, row 'Isobutanol', columns AO_RIB40_R1 and AO_RIB40_R2)
• isobutyraldehydearomaaldehydereads as fruity taste (PubChem)Measured in 6 of 338 ingredients.cite

  660.61 and 577.84 ppm in rice koji against 0.34 ppm in unfermented rice — a roughly 1800-fold increase, the steepest fold-change of any compound in the table, and 60-80x what the A. flavus strains produced (8.40, 10.18) — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Aldehyde block, row 'Isobutanal', columns AO_RIB40_R1 and AO_RIB40_R2)
• MethacroleinaromaaldehydeMeasured in 1 of 338 ingredients.cite

  7.96 and 8.24 ppm in rice koji against 0.09 ppm in unfermented rice — an eighty to ninetyfold rise — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Aldehyde block, row 'Methacrolein', columns AO_RIB40_R1 and AO_RIB40_R2)
• 2-methylbutyraldehydearomaaldehydeMeasured in 11 of 338 ingredients.cite

  137.67 and 104.25 ppm in rice koji against 0.16 ppm in unfermented rice — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Aldehyde block, row '2-methyl-Butanal', columns AO_RIB40_R1 and AO_RIB40_R2)
• heptyl alcoholaromaalcoholreads as fragrant (PubChem)Measured in 8 of 338 ingredients.cite

  13.53 and 22.52 ppm in rice koji against 0 ppm in unfermented rice and 0 in both A. flavus strains — detected in the A. oryzae columns only — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Alcohol block, row 'Heptanol', columns AO_RIB40_R1 and AO_RIB40_R2)
• 3-methylbutanalaromaaldehydereads as apple-like odor (PubChem)Measured in 22 of 338 ingredients.cite

  278.73 and 226.30 ppm in rice koji against 0.41 ppm in unfermented rice — the second largest aldehyde, and 15-40x the A. flavus columns (6.45, 15.50) — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Aldehyde block, row '3-methyl-Butanal', columns AO_RIB40_R1 and AO_RIB40_R2)
• 2-Phenyl-2-butenalaromaMeasured in 1 of 338 ingredients.cite

  10.50 and 13.69 ppm in rice koji against 0 ppm in unfermented rice — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Aldehyde block, row '2-Phenyl-2-butenal', columns AO_RIB40_R1 and AO_RIB40_R2)
• isoamyl alcoholaromaalcoholMeasured in 43 of 338 ingredients.cite

  138.53 and 199.96 ppm in rice koji against 0.23 ppm in unfermented rice — a 600-900-fold rise — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Alcohol block, row 'Isoamyl Alcohol', columns AO_RIB40_R1 and AO_RIB40_R2)
• 2,3-DihydrofuranaromafuranMeasured in 1 of 338 ingredients.cite

  15.77 and 25.83 ppm in rice koji against 0 ppm in unfermented rice, and against 0.28-0.78 ppm in both A. flavus strains — the largest oxygen-heterocycle in the koji columns and effectively an A. oryzae marker in this dataset — McCarthy et al. 2025, Frontiers in Fungal Biology (Table 1, Furan/O-heterocycle block, row '2,3-Dihydrofuran', columns AO_RIB40_R1 and AO_RIB40_R2)