Subcritical water as hydrolytic medium to recover and fractionate the protein fraction and phenolic compounds from craft brewer’s spent grain

The valorization of the brewer's spent grain (BSG) generated in a craft beer industry was studied by subcritical water hydrolysis semi-continuous fixed-bed reactor. Temperature varied from 125 to 185 °C at constant flow rate 4 mL/min. Biomass yielded maximum 78% solubilized protein 185 °C. Free amino acids presented level 160 °C with value 55 mg free acids/gprotein-BSG. Polar acid lower temperatures than non-polar acids. total phenolic compounds reached This is same for aldehyde such as vanillin, syringic and protocatechuic aldehyde; however, hydroxycinnamic acids, ferulic p-coumaric, obtained 160 °C. allows fractionation bioactive compounds. Subcritical addresses opportunities small breweries be incorporated within biorefinery concept.