Michiyo Tsujimura : Google’s Doodle celebrates “Michiyo Tsujimura’s 133rd Birthday”

Michiyo Tsujimura : Google’s Doodle celebrates “Michiyo Tsujimura’s 133rd Birthday”

Michiyo Tsujimura (17 September 1888 – 1 June 1969) was a Japanese agricultural scientist and biochemist whose research focused on the components of green tea. She was the first woman in Japan to receive a doctoral degree in agriculture.


Tsujimura was born in 1888 in what is now Okegawa in Saitama Prefecture. She attended Tokyo Prefecture Women’s Normal School, graduating in 1909, and the Division of Science at Tokyo Women’s Higher Normal School. There, she was taught by the biologist Kono Yasui, who inspired in Tsujimura an interest in scientific research. She graduated in 1913 and became a teacher at Yokohama High School for Women in Kanagawa Prefecture. In 1917, she returned to Saitama Prefecture to teach at Saitama Women’s Normal School.

Tsujimura’s research career began in 1920 when she joined Hokkaido Imperial University as a laboratory assistant. At the time, the university did not accept female students, so Tsujimura worked in an unpaid position at the Food Nutritional Laboratory of the university’s Agricultural Chemistry Department.

There, she researched the nutrition of silkworms before transferring to the Medical Chemical Laboratory at the Medical College of Tokyo Imperial University in 1922. The laboratory was destroyed in the 1923 Great Kantō earthquake, so she transferred to RIKEN as a research student in October 1923. She worked in the laboratory of Umetaro Suzuki, a doctor of agriculture, and researched nutritional chemistry

Tsujimura and her colleague Seitaro Miura discovered vitamin C in green tea in 1924, and published an article titled “On Vitamin C in Green Tea” in the journal Bioscience, Biotechnology, and Biochemistry. This finding contributed to an increase in green tea exports to North America.

She was the first woman in Japan to receive a doctoral degree in agriculture.

Tsujimura retired from Ochanomizu University as a professor in 1955, but continued lecturing part-time until 1961. She was a professor at Jissen Women’s University in Tokyo from 1955 to 1963, when she became a professor emeritus. She was awarded the Japan Prize of Agricultural Science in 1956 for her research on green tea and was conferred the Order of the Precious Crown of the Fourth Class in 1968. She died in Toyohashi on 1 June 1969 at the age of 81

Google’s Doodle celebrates “Michiyo Tsujimura’s 133rd Birthday”

Have you ever wondered why green tea tastes so bitter when steeped for too long? Thanks to Japanese educator and biochemist Michiyo Tsujimura, and her groundbreaking research into the nutritional benefits of green tea, science has the answers. Today’s Doodle celebrates Michiyo Tsujimura on her 133rd birthday.

Michiyo Tsujimura's 133rd Birthday

Michiyo Tsujimura was born on this day in 1888 in Okegawa, Saitama Prefecture, Japan. She spent her early career teaching science. In 1920, she chased her dream of becoming a scientific researcher at Hokkaido Imperial University where she began to analyze the nutritional properties of Japanese silkworms.

A few years later, Tsujimura transferred to Tokyo Imperial University and began researching the biochemistry of green tea alongside Dr. Umetaro Suzuki, famed for his discovery of vitamin B1. Their joint research revealed that green tea contained significant amounts of vitamin C—the first of many yet unknown molecular compounds in green tea that awaited under the microscope. In 1929, she isolated catechin—a bitter ingredient of tea. Then, the next year she isolated tannin, an even more bitter compound. These findings formed the foundation for her doctoral thesis, “On the Chemical Components of Green Tea” when she graduated as Japan’s first woman doctor of agriculture in 1932.

Outside of her research, Dr. Tsujimura also made history as an educator when she became the first Dean of the Faculty of Home Economics at Tokyo Women’s Higher Normal School in 1950. Today, a stone memorial in honor of Dr.Tsujimura’s achievements can be found in her birthplace of Okegawa City.

Happy Birthday, Michiyo Tsujimura!

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