文摘
The objective of this work was to design an integrated process to valuate brewer's spent grain (BSG) proteins and arabinoxylans (AX) to be used as food ingredients. For this purpose, a sequential extraction of proteins and AX from BSG with increasing alkali (KOH or NaOH) concentrations of 0.1 M, 0.5 M, and 4 M, was optimized. A ratio of 1:2 (w/v) (weight of BSG by volume of alkali solution) at room temperature for 24 h was preferred to minimize reagents and energy consumption. To fully integrate the process, alkaline extracts were acidified to pH3 with citric acid, to obtain the protein-rich fractions. The AX were recovered by ethanol precipitation and citric acid and ethanol were recycled. This integrated extraction process allowed a yield of 82-85% of the BSG total proteins and 66-73% of total AX with formation of a cellulose rich residue almost devoid of nitrogen.