Spent grain – from waste to a healthy food ingredient

• Joncer Naibaho: – The desire to be a scientist, and the hope that maybe one day I will contribute to solving the food crisis motivates me to continue working hard.
• Spent grain is a by-product which could be used to make food.
• Joncer's supervisors are prof. Małgorzata Korzeniowska from UPWr and prof. Baoru Yang from the University of Turku in Finland

The need to help others drives his work

Joncer Naibaho has always dreamt of having a useful profession. As a child, he wanted to become a teacher, but later became intrigued by science and research, as it offers solutions to many of life’s problems. – When I was doing my BA in Food Science, I really liked it and enjoyed it. Since then, I have tried to paint my dream and my path to become a food scientist. Although it hasn’t been easy to get to where I’m currently at, the desire to be a scientist, and the hope that maybe one day I will contribute to solving the food crisis motivates me to continue working hard – he says about choosing his PhD student career.

He came to the UPWr Doctoral School due to the research topic proposed by prof. Małgorzata Korzeniowska, head of the Department of Functional Food Product Development at the Wrocław University of Environmental and Life Science. – I also chose the UPWr Doctoral School because I wanted to experience life abroad, and living in Poland creates the opportunity to travel all over the country and the European Union – says the doctoral student, admitting that he knew little about the country before coming to Poland.

– I only knew that the capital was Warsaw. That's all. I've never heard of Wrocław before. When I got an email from prof. Korzeniowska, I searched for the city on YouTube and I thought "nice, I’ll do it". It was hard at first, especially with the language. After going to a Polish course, I still know only a few basic phrases, such as “dzień dobry” but I love Wrocław. Wherever I travel, I always miss it – says Joncer, who is currently on an internship in Copenhagen.

"One man's trash is another man's treasure"

Joncer Naibaho's PhD focuses on improving the potential of brewers’ spent grain as a functional and/or nutraceutical ingredient. – The fact that spent grain is a by-product of the brewery industry which could be harmful to the environment is a really serious issue. However, this by-product contains high nutritional value such as dietary fiber, protein, fatty acid, and polyphenolic compounds which benefit human health – says the PhD student about his research work. His research is important not only from the perspective of using waste for food production, but also will reduce the harmful impact of spent grain on the environment.

According to the FAO, approximately 721 to 811 million people were suffering from hunger worldwide in 2020. The agri-food industry produces mostly by-stream products that go to waste, and as Joncer points out, food availability and diversification are needed to combat hunger.

– Spent grain is a complex material in which insoluble dietary fiber (IDF) predominates. From the perspective of food processing, dietary fiber plays an important role in food texture formation – says Joncer, adding that together with the team at the Department of Functional Food Development they discovered that spent grain preserved the consistency and improved the survival of lactic acid bacteria in yogurt during storage. However, spent grain is often found to disrupt texture formation of baked products such as cookies and bread, and tend to harden food products, due to the high amount of IDF. This phenomenon leads to an increase in energy used during food processing. – The challenge is to convert the insoluble dietary fiber into a soluble one, so that it will allow a better performance in food processing and a better final product – explains Joncer.

The scientists have already conducted several experiments using thermal and sound waves, autoclave treatment, conventional water-bath heating and two different ultrasound treatments. – The main objective is to evaluate the impact of those treatments on spent grain, particularly the release of biological compounds from the matrix, including fatty acids, protein, polyphenolic compounds and dietary fiber. We are also investigating the antioxidant properties as well as the techno-functionality of treated spent grain – he adds.

International partnerships

He is pursuing his PhD under the supervision of prof. Małgorzata Korzeniowska – Prof. Korzeniowska is a great supervisor. She allows me to be as creative as I want to explore my project. She’s also introduced me to her colleagues at the university to allow me to work with different professors in different departments. Like me, she likes to travel, so in addition to consulting my PhD we also often talk about traveling. She encourages me to enjoy my time in Poland and Europe, and not only to think about my research projects – says the doctoral student, emphasizing that maintaining a balance between work and rest is important for a scientist's mental health.

– The UPWr Doctoral School has offered me a generous grant, thanks to which I can conduct research, attend conferences and publish scientific papers. I love traveling, and the university has given me the opportunity to do so through the possibility of participating in international conferences and conducting research abroad – says Joncer, whose second supervisor is prof. Baoru Yang from the University of Turku in Finland, head of the Department of Chemistry and Food Development – I really enjoy working with both of my supervisors. They are incredibly professional. Their international cooperation encourages me to follow the same scientific path – says the PhD student.

– I’m passionate about research in the field of food science, so I’d like to continue my scientific career as a scientist. I hope that my work will be applied and will be used by the food industry and appreciated among other scientists – says Joncer, emphasizing that the next step in his career will probably be a post-doc.

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