Potential applications of brewery spent grain: Critical an overview

Brewery Spent Grain (BSG) is a fibrous residue composed mainly of cellulose, hemicellulose, and lignin. It is rich in proteins, fermentable sugars, and bioactive compounds. These characteristics make BSG an essential feedstock for obtaining different products with high added value. Although it is widely used for animal feed, its use as a commodity for other applications has aroused interest. In this sense, this review article aims to provide an updated overview of the main uses and potential applications of BSG, from a critical perspective. For that, research articles were selected according to pre-established criteria using ScienceDirect and Scopus databases. The bibliographic research showed that BSG is rich in protein and amino acids, which make it attractive to animal feed. BSG has been employed to biogas production due to its energy value. The chemicals element presence, such as carbon, nitrogen, and phosphorus show that the BSG is a nutrient font to plant and microorganism used in several bioprocesses. Also, BSG is a lignocellulosic material that makes it attractive to produce biochar used in soil remediation, as adsorbent, and biocatalyst. Besides of these uses, its potential for application in biorefinery especially to bioproducts obtention, such as enzyme, biopolymers, biocides, and biofuel have been highlighted. It was evident that BSG has been used for several industrial applications. However, studies of operational conditions, cost, and energy efficiency assessments, product performance studies, among many others, are still necessary for the consolidation of BSG as a feedstock.