Composition and Nutrient Value Proposition of Brewers Spent Grain

Abstract

Brewer's spent grain (BSG), a major brewing industry byproduct, is generated in large quantities annually. This review summarizes research into the composition and preservation of BSG, different extraction techniques for BSG proteins and phenolic acids, and the bioactivities of these phenolic components. Moreover, this article also highlights BSG integration into foodstuff for human consumption and animal feed supplements. BSG is considered a rich source of fiber, protein, and phenolic compounds. The phenolic acids present in BSG are hydroxycinnamic acids (ferulic, p-coumaric, and caffeic acids), which have many biofunctions, such as antioxidant, anticarcinogenic, antiatherogenic, and antiinflammatory activities. Previously, attempts have been made to integrate BSG into human food, such as ready-to-eat snacks, cookies and bread, to increase fiber and protein contents. The addition of BSG to animal feed leads to increased milk yields, higher fat contents in milk, and is a good source of essential amino acids. Therefore, many studies have concluded that integrating the biofunctional compounds in BSG into human food and animal feed has various health benefits.

An In Vitro Approach to Assess Nutrient Utilization of Brewers Dried Grains and Effects of Supplemental β-Glucanase on Swine Feed Ingredients

“…Exogenous enzymes do not improve nutrient utilization in diets containing insufficient amount of substrates (Zijlstra et al, 2010;Kwon and Kim, 2015;Park et al, 2016). Also, BDG had high concentrations of hemicellulose and lignocellulose (Ikram et al, 2017). The lignocellulose matrix has a rigid structure that may inhibit the action of enzyme (Lynch et al, 2016).…”

“…In present study, we failed to find the effects of supplementation of β-glucanase on the IVDMD in BDG or corn DDGS. The reason for this might be that BDG contains less amounts of β-glucans (less than 1%) than those of barley (Ikram et al, 2017), thus there may be little substrate for the enzyme to work on. Exogenous enzymes do not improve nutrient utilization in diets containing insufficient amount of substrates (Zijlstra et al, 2010;Kwon and Kim, 2015;Park et al, 2016).…”

Effects of brewers’ spent grain protein hydrolysates on gas production, ruminal fermentation characteristics, microbial protein synthesis and microbial community in an artificial rumen fed a high grain diet

“…As a result, its use to date has generally been limited to animal operations near breweries due to high energy costs of transportation [1]. Although drying is considered the most effective method for lowering storage and transportation costs, drying itself is an energetically expensive process [1,8].…”

“…Barley is the primary grain source used in the brewing industry with the derived BSG being rich in phenolic compounds and hordein and glutelin proteins. Emerging evidence indicates that phenolic compounds in diet exhibit antiin ammatory and antioxidant properties [8,10]. The unique structural features of barley proteins coupled with high concentrations of glutamine and hydrophobic and non-polar residues, offer the possibility of producing bioactive peptides with strong antioxidant and antimicrobial properties upon proteolytic degradation using commercially available proteinase or alkali solutions [11,12].…”

Valorization of brewer's spent grain using fermentation : potential for food sustainability

“…Yet, the high moisture and sugar content present in BSG speeds up the natural deterioration, making this biomass an unstable material. Drying can effectively lengthen the useable period of the BSG, while reducing the transport cost involved therein [14].…”