Cát Huy Dương (first, left) and his friends use steam-water distillation to extract essential oil from betel leaves. — Photos courtesy of Thùy An

Khánh Vân

HÀ NỘI — Betel leaf is popular in Việt Nam, with many people regularly chewing betel and areca nuts, or as an indispensable part of betrothal gifts during an engagement or wedding ceremony.

A student in Hà Nội has discovered another advantage of this kind of leaf –making hand sanitiser from its essential oil.

The idea was developed when Cát Huy Dương, a 17-year-old student at the High School for Gifted Students under the Vietnam National University - Hà Nội, studied different natural measures that are antibacterial but safe to clean his hands.

Suffering from an underlying skin disease, normal soap or hand sanitisers that use antibacterial chemical ingredients harm Dương’s skin, forcing him to seek products made from natural ingredients to stay clean.

As betel leaf is often used by Dương’s family members as a kind of medicinal plant for making mouthwash or treating skin rashes, he decided to study more about advantages of this plant and found that the leaf contains antibacterial compounds that can be used to make hand sanitiser.

To turn this idea into reality, Dương and his friends decided to carry out a research project to make hand sanitiser from the extraction of betel leaf oil.

They include ninth graders Vũ Khánh Linh and Lê Bảo Khuê and tenth grader Nguyễn Trí Dũng from TH School and ninth grader Nguyễn Ngọc Huyền from the International School of Việt Nam.

The antibacterial activity of phenolic chemicals and their derivatives in the betel leaf essential oil can inhibit a variety of bacteria, according to Dương.

The research determined how to obtain the essential oil of betel leaf through a distillation process, and use the essential oil to prepare a hand sanitiser.

However, things did not go as easily as the young students imagined.

“The biggest challenge is how to maximise the amount of oil extracted from the betel leaf. As each leaf contains a little amount of oil so it was hard to use normal extraction methods,” Dương said.

The COVID-19 pandemic was another challenge, he added. “We could not regularly meet to discuss or go to labs to do experiments together. It means the testing and research was disrupted, making the process harder and longer,” he said.

“There were times we felt exhausted and even thought of giving up after many failures and it also wasted a lot of our time,” he said.

However, these difficulties could not hinder the students’ determination and passion.

Efforts pay off

After many failures, Dương and his group finally found a way to extract oil from the betel leaf effectively and use the oil to produce hand sanitiser gels.

A steam-water distillation method was used to extract the essential oil from the betel leaf. Distilled water and NaCl solvent were added to the distillation process to increase the extraction efficiency, according to Dương.

The betel leaves were washed with distilled water to remove all contaminants. Then the samples were cut into small pieces and air-dried for a day, followed by steam-water distillation.

The essential oil was then used with ethyl alcohol and glycerol to make hand sanitisers.

The hand sanitiser was prepared using the Word Health Organisation recommended hand-rub formulation, but H202 was replaced with betel leaf essential oil, according to Dương.

Piper betel leaves. — Photo suckhoedoisong.vn

Tests showed that the hand sanitiser has a powerful antibacterial effect. When compared to alcohol substrate and other commercial hand sanitisers, betel leaf hand sanitiser has shown a strong antibacterial effect and the inhibition of E.coli is approximately 1.5 times, according to the students.

“We are very happy to get the results after almost nine months of ups and downs since we started the project in late 2020,” Dương said.

Khánh Linh, one of the group members, said the COVID-19 pandemic brought many risks for humans and seeing the pandemic’s adverse impacts prompted young people like her to think of products that are antibacterial but less harmful to protect people.

Vũ Khánh Linh is counting drops of essential oil extracted.

The young students’ efforts were internationally recognised. They won the silver medal in the environmental science section of the World Invention and Competition Exhibition (WICE) 2021 for their production of hand sanitiser from the extraction of betel leaf oil.

WICE is an international competition held by Indonesian Young Scientist Association in collaboration with SEGi College Subang Jaya of Malaysia as the learning platform to nurture young talented inventors who are active, creative and innovative.

Associate professor Tống Thi Thanh Hương from the Hanoi University of Mining and Geology, who supported the students to do the research, said although the students were young they all showed care and meticulousness during their work and were proactive in searching for different methods.

In spite of many challenges, with their own capacity, they finally succeeded, she said.

Future plans

The search for naturally occurring antibacterial compounds and their application in the manufacture of sanitiser products is beneficial to both the community and the environment.

Natural-origin products in cosmetics and detergents are always safe for users. It is a viable alternative to the chemicals commonly found in cosmetics and cleaning products.

Betel leaf essential oil has a high antibacterial activity. As a result, future research is being conducted into the use of the essential oil as a natural ingredient in some cosmetic products such as toothpaste and hand soaps, said Dương.

The initial success of Dương and his friends is expected to help nurture the young generation’s passion for science as well as their creativity and innovation. As Dương said: “Never giving up on your passion and goals. Starting from the smallest things, you will gradually succeed.” — VNS