Chilean project In vitro evaluation of pretreated and untreated enzymatically treated brewer's spent grain with potential application in functional diets for fish is evaluating the effect of brewer's spent grain as a potential supplement for salmon aquafeeds. Researchers are assessing, through pretreatment, its possible toxicity, pro-inflammatory, anti-inflammatory, and antioxidant effects on cell viability and the expression of immune and antioxidant genes in fish cells.
"We have studied how to extract bioactive compounds from brewer's spent grain. This allowed us to efficiently obtain phenolic acids and prebiotics. In addition, an enzymatic pretreatment improved the availability of these compounds, and optimizing the extraction process and using vacuum microwave drying resulted in better extract properties," explained María Cristina Ravanal, director of the initiative and academic at ICYTAL of the Faculty of Agricultural and Food Sciences of the UACh.
"We also analyzed the extracts in salmonid cells and found that, at low concentrations, the extract stimulates the immune response and modulates oxidative stress genes. Furthermore, it showed antimicrobial effects against Piscirickettsia salmonis, an important pathogen in aquaculture," the researcher added.
Researchers suggest that brewer's spent grain extracts have the potential to be used as additives in fish feed, which could contribute to improving health and strengthening the resistance of farmed salmonids.
Brewer's spent grain constitutes approximately 85% of the waste generated by the brewing industry globally (Mussatto, 2014), which makes its reuse a topic of growing interest for both small and large beer-producing companies.
"This project addresses challenges such as the management of brewery waste and the reduction of antibiotic use in salmon farms in southern Chile and generates a positive impact in several fields. In the brewing industry, it offers solutions and uses its waste to obtain valuable compounds that promote the circular economy. In the aquaculture industry, it would target animal welfare and reduce the use of antibiotics with these functional additives," said Ravanal.
Researchers plan to perform in vivo studies incorporating the extracts into feed and analyze their effect on the health and performance of the fish.
The project is funded by InES Gender of the Austral University of Chile (UACh) and carried out in collaboration with Cerveza Kunstmann, the Institute of Food Science and Technology (ICYTAL) of the UACh, and the AQUAIST Laboratory of this university.
