Born: 17 September 1888, Japan
Died: 1 June 1969
Country most active: Japan
Also known as: 辻村みちよ
The following bio was written by Emma Rosen, author of On This Day She Made History: 366 Days With Women Who Shaped the World and This Day In Human Ingenuity & Discovery: 366 Days of Scientific Milestones with Women in the Spotlight, and has been republished with permission.
Michiyo Tsujimura (辻村みちよ) was a Japanese agricultural scientist and biochemist known for her pioneering work on green tea components. She was the first woman in Japan to earn a doctoral degree in agriculture.
In 1920, Tsujimura joined Hokkaido Imperial University as a laboratory assistant. Notably, the university did not admit female students at the time. Consequently, Tsujimura volunteered at the Food Nutritional Laboratory within the university’s Agricultural Chemistry Department. Here, she conducted research on silkworm nutrition. In 1922, she moved on to the Medical Chemical Laboratory at Tokyo Imperial University’s Medical College.
In 1923 the Great Kantō earthquake destroyed the laboratory. Undeterred, Tsujimura relocated to RIKEN in October 1923, where she worked as a research student under the guidance of Umetaro Suzuki, a respected agricultural doctor. Her focus remained on nutritional chemistry.
In 1924, Tsujimura, alongside her colleague Seitaro Miura, made a groundbreaking discovery by identifying vitamin C in green tea. Their findings were documented in an article titled “On Vitamin C in Green Tea,” published in the journal Bioscience, Biotechnology, and Biochemistry.
Tsujimura continued her outstanding contributions to the field, isolating the flavonoid catechin from green tea in 1929 and crystalline tannin in 1930. Her extensive research culminated in her doctoral thesis, “On the Chemical Components of Green Tea,” which earned her a doctorate in agriculture from Tokyo Imperial University in 1932 as the first Japanese woman to attain such a degree.
Later, she isolated gallocatechin from green tea in 1934 and patented her method for extracting vitamin C crystals from plants in 1935. Tsujimura became a junior researcher at RIKEN in 1942 and a researcher in 1947. Ultimately, she became a professor at Ochanomizu University when it was founded in 1949, later serving as a professor at Tokyo Women’s Higher Normal School from 1950 and becoming the school’s first dean of the Faculty of Home Economics.