Recently, undergraduate students from the Environmental Science program at BNBU have published a research paper in a top-ranked international journal. The paper, titled "Pretreatment of spent coffee grounds for edible insect farming: impacts on mealworm (Tenebrio molitor) development and gut microbiome," appeared in Sustainable Food Technology, a journal of the Royal Society of Chemistry. The first and third authors are Du Ruoxin and Zhang Tiantian, undergraduates in the ENVS program, while the corresponding authors are Dr. Danny Chi Man Leong, Assistant Professor in ENVS, and Dr. Matthew Yuk-Yu Lui, Assistant Professor in the Department of Chemistry, Faculty of Science and Technology, at Hong Kong Baptist University.

Sustainable Food Technology is a journal published by the Royal Society of Chemistry (RSC). It has a 2025 impact factor of 9.0 and is ranked Q1 in "Food Science and Technology" in the Journal Citation Reports (JCR). The journal covers green food processing, waste resource utilization, and the circular economy, and aims to share research that makes food systems more sustainable.

Their study focuses on turning food processing residues such as spent coffee grounds into useful resources, an approach that could help cut solid waste and support a circular economy. The team found that treating the grounds with ethanol removed about 96% of the caffeine. When the mealworms were fed a mix containing the treated grounds, they grew and pupated better than those fed untreated grounds. Their gut microbial communities also differed. Together, these results show that insects can help convert food waste into useful resources, offering a new path toward more sustainable resource use.

The project also received support from a provincial innovation and entrepreneurship competition (project title: "From Waste Residue to Resource: Developing Green Conversion Technology for Mealworm Degradation of Spent Coffee Grounds"), and two related patents have been filed to further explore the potential applications of the research.

The study took two years from start to finish. Throughout that time, the sustained guidance of the two supervisors, Dr. Danny Chi Man Leong and Dr. Matthew Yuk-Yu Lui, in research design, analysis, and paper revision, along with research support and interdisciplinary collaboration between BNBU and Hong Kong Baptist University, provided the conditions needed to move the project forward. Through hands-on collaboration on experiments, and by working with different research teams and service providers for patent applications and sequencing, Du Ruoxin and Zhang Tiantian gradually deepened their understanding of research collaboration. They learned to express their research needs clearly and to negotiate the details of partnerships, strengthening their practical research skills and their ability to communicate and work as part of a team.

Behind these results lie years of sustained study and effort. Du Ruoxin joined Dr. Liang Zhiwen's research team in her first year and has since published two SCI papers. Zhang Tiantian joined the group in her second year and worked alongside Du Ruoxin on the experiments, making important contributions to the research. In March of this year, the two teamed up to take first prize at the inaugural BNBU Undergraduate Sustainability Symposium and Competition. They then attended the inaugural BNBU-Soka Undergraduate Sustainability Forum as representatives, engaging in academic exchange with students from Soka University of America. From their research on repurposing spent coffee grounds to the competition and international exchange, the two have moved from the lab to a broader academic stage. The two-year project taught them, on a deeper level, about the patience and responsibility that research demands, and how to sharpen their judgment through constant revision.

Du Ruoxin (left), Zhang Tiantian (center), and Dr. Danny Chi Man Leong (right) won first prize at the inaugural BNBU Undergraduate Sustainability Symposium and Competition.

The findings in the research came from long-term experimental work, data organization, literature review, and repeated revision. Du Ruoxin and Zhang Tiantian built their research skills gradually through this kind of sustained practice. They learned basic methods first, and over time grew able to pose scientific questions, analyze evidence, and coordinate collaborations. Their work reflects how the BNBU Environmental Science program has long trained outstanding undergraduates by integrating teaching, learning, and research.

Written by: Du Ruoxin and Zhang Tiantian

Edited by: Shimei He

Reviewed by: Siu-tai TSIM

Translated by: Julia Miyagawa Braga