Characterization and discrimination of volatile organic compounds in quinoa-adjunct beer brewed with 6 differently
Qichang Chen1, Lu Wang2, Jian Lu3
1School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, PR China; National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, PR China; Qingdao Laomai Beer Co., Ltd., Qingdao 266105, PR China; Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi 214122, PR China.
Abstract:
As a nutrition-balanced pseudocereal, quinoa is gaining attention in beer brewing. This study comprehensively characterized volatile organic compounds (VOCs) in quinoa-adjunct beer using GC-E-Nose, GC-IMS and GC-MS. These techniques totally identified 117 VOCs and discriminated the VOC characteristics of all-malt beer and quinoa-adjunct beer brewed with differently colored quinoa varieties efficiently combined with principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). In contrast to all-malt beer, quinoa-adjunct beer contained 9 unique VOCs and exhibited a 69.72% higher total VOC content (particularly RB). Based on variable importance prediction (VIP) and odor activity value (OAV), 9 key differential odor-active compounds (VIP > 1 and OAV > 1) were selected. Quantitative descriptive sensory analysis (QDA) and partial least squares regression (PLSR) demonstrated these 9 compounds correlated highly with floral and fruity notes. Correlation analysis linked increased glucose level in quinoa-adjunct wort to enhanced VOC formation, especially esters.
