title: Evaluation of Beer Fermentation with a Novel YeastWilliopsis saturnus.
abstract: The aim of this study is to evaluate the potential of a novel yeastWilliopsis saturnusvar.mrakiiNCYC 500 to produce fruity beer. Fermentation performance ofW. mrakiiand beer volatile composition were compared against that fermented withSaccharomyces cerevisiaeSafale US-05.oBrix, sugar and pH differed significantly between the two types of beer. A total of 8 alcohols, 11 acids, 41 esters, 9 aldehydes, 8 ketones, 21 terpenes and terpenoids, 5 Maillard reaction products and 2 volatile phenolic compounds were detected. Yeast strain Safale US-05 was more capable of producing a wider range of ethyl and other esters, while yeast strain NCYC 500 produced significantly higher amounts of acetate esters. Strain NCYC 500 retained more terpenes and terpenoids, suggesting that the resultant beer could possess more of the aromatic hint of hops. This study showed thatW. saturnusvar.mrakiiNCYC 500 could ferment wort to produce low-alcohol beer with higher levels of acetate esters, terpenes and terpenoids than yeastS. cerevisiaeSafale US-05.
authors.affiliation: Food Science and Technology Programme, Department of Chemistry, National University of Singapore, Science Drive 3, 117543 Singapore, Singapore; National University of Singapore (Suzhou) Research Institute, No. 377 Linquan Street, Suzhou Industrial Park, 215123 Suzhou, PR China.
authors.forename: Shao-Quan
authors.initials: SQ
authors.lastname: Liu
authors.affiliation: Food Science and Technology Programme, Department of Chemistry, National University of Singapore, Science Drive 3, 117543 Singapore, Singapore.
authors.forename: Althea Ying Hui
authors.initials: AY
authors.lastname: Quek
keywords: Williopsis sp.; beer; esters; fermentation; volatiles; yeasts