Brewer’s spent grains (BSG) contains more than half the daily recommended dietary fiber (62%!), complete plant protein, and medium-chain fatty acids:
- is a lignocellulosic material rich in protein and fiber (cellulose, arabinoxylan and lignin) accounting for approximately 20 and 70% respectively
- is reported to contain vitamins (biotin, folic acid, niacin, choline, riboflavin, thiamine, pantothenic acid and pyridoxine) and minerals (calcium, cobalt, copper, iron, magnesium, manganese, phosphorus, potassium, selenium, sodium and sulphur).
- Both essential (including lysine, histidine, methionine, phenylalanine and tryptophan) and non-essential (including alanine, serine, glycine and proline) amino acids are also reported to be present in BSG (Mussatto et al. 2006).
- is rich in phenolic compounds (principally ferulic acid and p-coumaric acid) along with oligo-saccharides and polysaccharides. Evidence of dietary phenolic compounds to exhibit anti-carcinogenic, anti-inflammatory and antioxidant activities have been found recently.
Similar to other lignocellulose material, BSG is reported to contain various valuable materials within. One of the main reasons hindering the possessing of those is due to the recalcitrance of plant cell walls. Therefore, physical, chemical or biological conversion needs to be performed on the BSG.
Specific to animal feed, from Jack Britt’s excellent presentation on Wet brewer’s grains (WBS) compared to Hay and Corn:
How barley grain compares to other grains
Spent grains nutritional overview – rich in protein, fiber, phenolic compounds, vitamins and more