Versatile Applications of Brewer's Spent Grain: Solid-State Fermentation and Nutritional Added Value

Area of Science:

• Biotechnology
• Food Science
• Sustainable Agriculture

Background:

• Brewer's spent grain (BSG) is a major, protein-rich brewing byproduct, with most proteins remaining insoluble.
• Solid-state fermentation (SSF) is a bioprocess utilizing minimal water, known to improve the nutritional profile of substrates like BSG.

Purpose of the Study:

• To review the potential applications of nutrients (proteins, amino acids, phenolics, sugars) extracted from BSG using SSF.
• To explore the industrial-scale prospects of BSG utilization in animal feed, human diets, and as a microbial substrate.

Main Methods:

• Review of existing literature on Solid-State Fermentation (SSF) of Brewer's Spent Grain (BSG).
• Analysis of nutritional enhancements in BSG through microbial action during SSF.
• Exploration of strategies to improve SSF yield, including symbiotic fermentation and nutrient supplementation.

Main Results:

• SSF enhances the protein, amino acid (proline, threonine, serine), phenolic, and soluble sugar content of BSG.
• BSG processed via SSF shows potential for incorporation into animal feed, human food products, and as a substrate for microbial cultivation.
• Advances like symbiotic fermentation and nitrogen supplementation can improve fermentation yields.

Conclusions:

• Solid-state fermentation offers a sustainable method for valorizing brewer's spent grain, enhancing its nutritional value and expanding its applications.
• Addressing challenges in SSF optimization, bioreactor design, and operational costs is crucial for industrial-scale implementation.
• Further research into SSF of BSG can unlock significant benefits for sustainable resource utilization.