Valorization of Spent Grains from Beer Production through β-Glucan Extraction

Brewers' spent grains (BSG) are the major byproduct of the brewing industry. Recently, it has been found that beta-glucan, which can be used as a food supplement, can be extracted from BSG and offers the greatest added value. This study aimed to investigate the effects of temperature (45-90 degrees C) and time (30-120 min) on beta-glucan extraction efficiency when using hot water extraction. beta-glucan was precipitated upon 80% ethanol addition. The chemical compositions were examined. The highest beta-glucan concentration and yield were obtained at a temperature and time of 60 degrees C and 90 min, respectively. The functional properties of the extracted beta-glucan were analyzed and compared with other commercial stabilizers such as sodium carboxymethyl cellulose (CMC), xanthan gum, gum arabic, and oat beta-glucan. All stabilizers exhibited non-Newtonian flow behavior, except for gum arabic, which exhibited Newtonian flow behavior. The water holding capacity of BSG beta-glucan was 6.82 g/g and the creaming index of the emulsions stabilized with BSG beta-glucan was 89.05%. BSG beta-glucan improved the color and stability of orange juice by reducing the precipitation of orange pulp. This study illustrated that BSG beta-glucan can be used as a stabilizer and viscosity enhancer in foods, depending on the concentration, which can be applied to a variety of foods.