LAUSR

Two byproducts, brewer’s spent grain (BSG; germinated rice and malt) and brewer’s spent material (BSM; Achyranthes japonica Nakai), were collected during the manufacture of pilsner beer using A. japonica Nakai and germinated rice. Water extracts of BSG and BSM were prepared at different temperatures (25°C, 60°C, and 100°C) for 5 h, and their nutritional and functional properties were investigated. γ-Aminobutyric acid (GABA), saponin, and niacin contents were higher in extracts prepared at 60°C for more than 3 h than the other extracts, whereas total polyphenol content, DPPH radical scavenging activity, and reducing power were higher in samples extracted at 100°C for 1 h compared to the other ones. Overall, water extraction at 60°C for 3 h was desirable to effectively collect both nutritional and functional components from BSG and BSM. Under these conditions, BSM extracts showed 4∼18 times high niacin and folate contents, 1.4 times high total phenolic content, and 11∼60 times high antioxidant activities compared to BSG extracts. This study shows that pilsner beer byproducts would be good sources of health beneficial components, especially GABA, saponin, water soluble vitamins, and polyphenolics.