Researchers from Nanyang Technological University, Singapore (NTU Singapore), have created a method that extracts over 80 percent of the protein in grain leftovers from brewing beer, commonly known as brewers’ spent grain (BSG).
BSG is the solid residue from malted barley after brewing beer, making up 85 percent of the total waste. While some efforts are made to repurpose BSG, a substantial portion remains in landfills, generating greenhouse gases.
After exploring new use cases for the BSG proteins, the researchers from NTU’s Food Science and Technology programme identified that the extracted proteins could enrich diets and even for cosmetic purposes, feeding into growing consumer preferences towards sustainability.
The researchers extracted up to 200 grams of protein from one kilogram of BSG, indicating its potential as a protein source, safe for human consumption and suitable for direct use in supplements and for enhancing the protein content of plant-based foods.
This would also help mitigate a possible protein shortage due to a forecast of a 73 per cent increase in meat consumption by the year 20503 following rapid global population growth, according to the Food and Agriculture Organisation of the UN (FAO).
The proteins extracted by the NTU researchers were also rich in antioxidants, which could protect human skin from pollutants and extend the shelf life of cosmetics like body lotions and moisturisers.
“Our study, which presents more sustainable and efficient ways to add value to brewers’ spent grain disposal, is a crucial step towards mitigating its contribution to greenhouse emissions and reducing environmental strain while enriching the global food supply chain,” said lead author Professor William Chen, director of NTU’s Food Science and Technology (FST) programme.
“Demonstrating that the protein-rich qualities of brewers' spent grain could be successfully extracted and funnelled into supplements and enriching plant-based proteins to make them more attractive to the consumer addresses two global pressure points – food wastage and food shortage.”
The study reflects NTU's commitment to mitigating environmental impact, one of four challenges humanity faces that the university seeks to address through its NTU 2025 strategic plan.
The NTU FST Programme collaborated with Heineken Asia Pacific, the producer of Tiger Beer, using the brewers' spent grain in the study. The NTU FST team will be in discussion with Heineken Asia Pacific to scale up the protein extraction method, and they plan to collaborate with food and beverage and cosmetic companies to implement their technology further.
