Sweet potato-malt worts were prepared by using sweet potato paste of Shinyulmi and Shinjami as the main adjunct, enzymes, malt, hop, and water. We brewed low-malt beers of the lager- or ale-type by using these worts and inoculating bottom and top fermenting yeast, respectively. Moreover, the componential and functional characteristics of the resulting beers were evaluated. During saccharification of sweet potato, the addition of an enzyme agent containing α-amylase caused an improvement in filterability and an increase of total sugar. The sugar content of sweet potato-malt wort which was prepared by the addition of 0.1% enzyme agent containing α-amylase and a three-step infusion procedure was 13.5 °Brix adequate for beer brewing. The polyphenol and anthocyanin contents of Shinjami beer were increased with increasing content of the paste, and also increased DPPH and ABTS radical scavenging activities. But in Shinyulmi beer it were decreased. A strong correlation was obserbed between antioxidave activities and polyphenol and anthocyanin contents of sweet potato beers. In all lager- and ale-type low-malt beers using 41.6% of Shinjami pastes, sensory attributes very similar to those of 100% malt beer were obtained and they were very good as they had unique red color.

• 양하나((주)강동오케익) | Ha-na Yang (Gang Dong-O Cake Co. Ltd, Jeonju 54801, Korea)
• 오은비(우석대학교 대학원 식품생명공학과) | Eun-Bi Oh (Dept. of Food Science & Biotechnology, Graduate School, Woosuk University, Wanju 55338, Korea)
• 박정섭((주)대두식품) | Jeong-Seob Park (Daedoo Foods Co., Ltd, Kunsan 54052, Korea)
• 정문웅(우석대학교 대학원 식품생명공학과) | Mun-Yhung Jung (Dept. of Food Science & Biotechnology, Graduate School, Woosuk University, Wanju 55338, Korea)
• 최동성(우석대학교 대학원 식품생명공학과) | Dong-Seong Choi (Dept. of Food Science & Biotechnology, Graduate School, Woosuk University, Wanju 55338, Korea) Corresponding author