Team:Kobe/HP/Gold Integrated

Integrated Human Practices

Visit to tea farm

For our Human Practice project, we hope to help promoting Japanese tea with our biosensor. Our tea-quality theanine sensor should be useful when our project reflects the actual situation of tea industry. The best way to learn and better understand the current situation of Japanese tea world is, literally to get out of the lab and experience it with our hearts!

Interview with Mr.Matsumoto: The owner of a farm house, “Teppen”

8 Oct. 2017

We visited a tea farm house, “Teppen” in Ehime prefecture.

The link of the farm house

They cultivate “Yabukita”, a type of tea plant usually used for green tea. We heard a lot of interesting and useful information related to our project.

Below are the topics we heard.

○ Some of the marketed green tea contains additives.

They sometimes tastes marketed tea pruduct. Cheap or imported ones often contain additives to enhance the taste of the tea.

Mr.Matsumoto said he can learn whether additives are contained in the tea or not by putting it overnight. If they contain lots of additives, the tea will turn into milky color.

According to the following references, the custom of adding monosodium glutamate (MSG) into green tea is widely seen from Sanin Region through into the Hokuriku region in Japan.


The amount of additives in tea can be determined by the ratio of glutamate content to the theanine content.

In the case of natural tea (without additives), the value of this ratio is about 0.2 or less. However, this ratio sometimes exceeds more than 0.4 in cases where the tea is containing the additive. Glutamate is often added to enhance umami in Japanese green tea, but that taste is quite different from the original one(umami of theanine). Our theanine sensor can be used to detect the additives in tea.

○The taste of green tea is affected by many factors.

There are many factors that could change the taste of tea. The taste of tea is variable even if it is cultivated in the same way. For example, the factors include the places they are planted, the degree of damage caused by insects, and the way of processing the tea.

Only the large scale facilities own the devices to analyze the components in tea because such devices are expensive. Small farms cannot afford them so they cannot check their tea quality when they want. We realized again the importance of synthetic biological tool to measure the tea quality.

○Decrease in consumption of green tea

According to the following references, the consumption of green tea in Japan is decreasing these days.


Indeed, the tea farmers also mentioned the decrease in green tea sales. Our "theanine sensor" would help promoting Japanese tea. Natural green tea contains a lot of L-theanine. Our sensor will prove that!

After the interview, the owner generously allowed us to experience tea-picking and hand-rolling. (Hand rolling is the primary process of making green tea)

Tea leaves were heated to be softened.
Hand-rolling to dry tea leaves
Green tea was exposed in the sun. Dried tea leaves can be preserved for a long time.
They helped us create our booklets.

Interview with the representative of Benifuuki group

9 Oct. 2017

We interviewed the representative of Benifuuki group.

“Benifuuki” is a type of tea commonly used for black tea. But these days, it is also used for green tea because of its high content of catechin, the substance which suppresses the symptoms of hay fever. We heard interesting stories there.

The necessity of small device to analyze the components of tea accurately

Analyzing the component of tea in a publicly certified way is difficult without costs. We believe that small biosensor will be able to measure the components of tea accurately and will be publicly certified.

Survey on Tea Culture

As a human practice project, we decided to help promoting Japanese tea to the world. We carried out a survey to collect useful data for promoting Japanese tea.

Percentage of individuals from different places who took the survey.

As indicated in the chart above, in Japan, there are greater number of people who enjoy tea. For this data, we can say that enjoying the taste of tea has become an important part of Japanese culture.

All participants who took the survey have already tasted green tea somewhere. Most of them already heard about Japanese tea product. Japanese tea seems to be more famous than we have thought.

Even though green tea has been an important part of food culture in Japan, green tea does not have big market share in Japan compared to other region.

In all regions, at least about 40% people think that health effect is a very important aspect when choosing tea. Most of them know that different type of tea have different effects on one's health. Many people are interested in health effects of tea. The day that theanine attract attention is near.

Theanine is more familiar in Japan than in other regions. (Except for category other regions in which there are only two people.) Some people pointed out that Japanese has a lot of interest in the healthy beverage in the free-answer column of the survey. We agree with this opinion.

Organization Chart

  • Ehime Prefecture International Center
    Secretary‐general Ryo Takaoka
  • Matsuyama International Center(MIC) 
    Maki Mizuno
  • 愛媛県中予地方局商工観光室
    Miyuki Yamanaka
  • 愛媛県港湾管理事務所

Our sincere thanks to these people!