CHIZU — the atlas of coffee research
Coffee research in Japan
Two limits come with this count. Only 100,474 of the 190,643 searchable papers (52.7%) carry an author affiliation country. The other 90,169 (47.3%) carry none. So these 2,822 papers are 2,822 out of the 100,474 whose affiliation is known. And a co-authored paper is counted once for every country its authors sit in. Per-country counts therefore do not add up to the whole.
Japan does not grow coffee, but coffee is researched there.
Check it yourself
This is not our word for it. You can run the same query against the same index.
When they were written
1806–2026
2,821 of the 2,822 papers carry a year. The rest have none.
Years before 1600 are treated as unknown. The upstream data (OpenAlex) sometimes writes 1400 when the year is missing, and that is a placeholder, not a measurement.
Where they appeared
Top 8 sources (journals and repositories)
Most cited
10 papers, most cited first
- International trade drives biodiversity threats in developing nations2012cited 1,226
- HPLC Method for Evaluation of the Free Radical-scavenging Activity of Foods by Using 1,1-Diphenyl-2-picrylhydrazyl1998cited 1,108
- Prevalence of smoking among psychiatric outpatients1986cited 1,067
- In vitro and in vivo antioxidant properties of chlorogenic acid and caffeic acid2010cited 958open access
- Frequency of bowel movements and the future risk of Parkinson’s disease2001cited 830
- Coffee: biochemistry and potential impact on health2014cited 544
- The Relationship between Green Tea and Total Caffeine Intake and Risk for Self-Reported Type 2 Diabetes among Japanese Adults2006cited 463
- Association of hyperglycemia with reduced heart rate variability (The Framingham Heart Study)2000cited 439
- Green tea consumption and cognitive function: a cross-sectional study from the Tsurugaya Project2006cited 427
- Caffeine and related purine alkaloids: Biosynthesis, catabolism, function and genetic engineering2007cited 419
Which stage of coffee
Only 30.2% of the whole index carries a stage label. Of this country's 2,822 papers, 1,141 carry one. The breakdown below is about those 1,141 papers only — the rest were never candidates for it.
One paper can carry several labels, so the breakdown adds up to more than that number.
Which field
Only 75.9% of the whole index carries a field label. Of this country's 2,822 papers, 2,249 carry one. The breakdown below is about those 2,249 papers only — the rest were never candidates for it.
One paper can carry several labels, so the breakdown adds up to more than that number.
What language
"undetermined" means the upstream record carried no language. We did not guess one.
Knowledge is not evenly spread
Counting only papers whose author affiliation is known, the largest is Indonesia with 22,248. Japan has 2,822 — a factor of 8.
That gap does not follow where coffee is grown. Research gathers where the means to do research are, not where the coffee is. Making that visible is why CHIZU exists.
Other countries
Indonesia 22,248United States 17,988Brazil 10,857United Kingdom 5,569China 4,887India 3,542Germany 3,185Italy 3,111France 3,072Colombia 2,489Spain 2,363Canada 2,352