Assessment of Brewery Spent Grains as a Source of Protein in Food Applications

Brewery wasted grains (BSG) are the leftovers of the brewing process. They are created after the mashing process and are filtered out. Despite their potential as a major protein resource, they are generally disregarded. BSG is often utilised as animal feed and plant nutrition. This research examined the use of Brewer's Spent Grain (BSG) as a protein source for culinary applications, with a specific emphasis on Uganda Breweries. The proximate analysis technique was used to determine the nutritional content of BSG. The results showed that it contains around 82% moisture, 47% fibre, 8.6% fat, and 5% ash, showing that it is nutritionally rich. By using the Dumas technique, it was determined that the protein content was 25% (25g/100g w/w), which established the basis for conducting protein extraction tests. The protein extractability from BSG was investigated using alkaline soluble acid precipitation and Bradford tests. The results showed that up to 25% of the protein could be extracted, with the highest extraction efficiency seen at pH 3.8. It is advisable to conduct sensory assessment and consumer acceptability testing to assess the characteristics and marketability of products made from BSG. Additionally, additional investigation should be conducted to examine the mineral content, carbohydrates, and liquid content of BSG, to enhance our knowledge of its appropriateness for culinary applications. The findings highlighted the potential of BSG as a viable and long-lasting source of protein. By creatively integrating protein obtained from brewer's spent grain (BSG) into food items, we can enhance sustainability in the brewing sector and support a circular economy. This research aims to enhance the value of BSG by not only reducing waste but also solving food security problems via using its high nutritional content for human consumption. Collaboration among brewers, food producers, and academics is essential for advancing innovative projects that seek to exploit the potential of BSG. This collaboration will help establish a more sustainable and resilient brewing business and beyond. Keywords: Brewery spent grain, Proximate content, Nutritional, Food manufacturers, Uganda breweries