Who is Michiyo Tsujimura? The life and achievements of Michiyo Tsujimura, a Japanese scientist who overcame the great difficulties of his time.
Michiyo Tsujimura (辻 村 み ち よ? September 17, 1888 – June 1, 1969) was a Japanese agricultural scientist and biochemist whose search focused on the components of green tea. She was the first woman in Japan to receive a Ph.D. in agriculture.
Tsujimura was born in 1888 in what is now Okegawa, in Saitama Prefecture. She attended Tokyo Prefectural High School for Women, graduating in 1909, and the Science Division at Tokyo High School for Women. There her teacher was the biologist Kono Yasui, who inspired Tsujimura’s interest in scientific research. She graduated in 1913 and became a teacher at the Yokohama Institute for Women in Kanagawa Prefecture. In 1917 she returned to Saitama Prefecture to teach at the Saitama High School for Women.
Tsujimura’s research career began in 1920 when she joined Hokkaido Imperial University as a laboratory assistant. At that time the university was not accepting female students, so she Tsujimura worked in an unpaid position in the Food Nutrition Laboratory of the university’s Department of Agricultural Chemistry. There he did research on the nutrition of silkworms before moving to the Medical Chemical Laboratory of the Tokyo Imperial University School of Medicine in 1922. The laboratory was destroyed in the great earthquake of 1923, so he went to the institute of Japan Natural Science Research, RIKEN, as a research student in October 1923. He worked in the laboratory of Umetaro Suzuki, a Ph.D. in agriculture, and did research on nutritional chemistry. Tsujimura and his colleague Seitaro Miura discovered vitamin C in green tea in 1924, and published an article titled “Vitamin C in Green Tea” in the journal Bioscience, Biotechnology, and Biochemistry. green tea exports to North America.
In 1929, Tsujimura isolated catechin, a flavonoid, from green tea. He extracted the tannin in crystal form from green tea in 1930. His thesis on the components of green tea, entitled “On the Chemical Components of Green Tea”, earned him a doctorate in agriculture at the Imperial University of Tokyo in 1932, making him the first woman in Japan to achieve that degree. It was by isolating gallocatechin from green tea in 1934 that she filed a patent on her method of extracting vitamin C crystals from plants in 1935. She was promoted to the role of junior researcher at RIKEN in 1942 and then to the position of researcher in 1947, to later become a professor at Ochanomizu University when it was founded in 1949. She was a professor at the Tokyo Women’s High School since 1950 and was the first dean of the School of Home Economics.
Tsujimura retired from Ochanomizu University in 1955, but she continued to teach part-time until 1961. She was a professor at Jissen Women’s University in Tokyo from 1955 to 1963, when she was recognized as a professor emerita. She was awarded the Japan Agricultural Science Prize in 1956 for her research on green tea and was awarded the Order of the Precious Crown, Fourth Class, in 1968. She died in Toyohashi on June 1, 1969 at the age 81.