Intensification of Xylo-oligosaccharides Production by Hydrothermal Treatment of Brewer’s Spent Grains: The Use of Extremely Low Acid Catalyst for Reduction of Degradation Products Associated with High Solid Loading

Brewers’ spent grains (BSG) make up to 85% of a brewery’s solid waste, and is either sent landfill or sold as cheap animal feed supplement. Xylo-oligosaccharides (XOS) obtained from BSG are antioxidants prebiotics that can be used in food formulations low-calorie sweeteners texturisers. The effect extremely low acid (ELA) catalysis liquid hot water (LHW) hydrothermal treatment (HTT) was assessed using with dry matter contents 15% 25%, achieved by dewatering screw press. Batch experiments at loadings 5, 12.5 20 mg/g mass temperatures 120, 150 170 °C significantly affected XOS yield both levels considered. Maximum yields 76.4% (16.6 g/l) 65.5% (31.7 were raw pressed respectively, 5 mg acid/g mass, after 15 min min, respectively. These containing 63% less more than lower reported previously. finding confirms ELA dosing LHW HTT allows lowering the required temperature result reduction degradation products, which especially relevant under high conditions. This substantial production intensification through higher not only product yield, but also provided benefits such increased concentrations decreased process heat requirements.