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[Display omitted] • Influence of serving temperature on aroma release and perception of Huangjiu were investigated. • Quantitative description analysis showed 17 attributes significantly influenced by temperature. • Different types and temperatures of Huangjiu were visualized by fingerprint spectral profiles. • Multivariate analysis and aroma adding experiment predicted 22 key odorants in Huangjiu. Serving temperature plays a crucial role in influencing the sensory experience of consumers. In this context, this study investigated the influence of serving temperature on the aroma release and perception of a typical fermented alcoholic beverage named Huangjiu. A quantitative sensory description analysis was conducted, determining serving temperature significantly influenced the 17 sensory attributes in both semi-dry and semi-sweet Huangjiu. The variation in the contents of 41 volatiles in the Huangjiu with temperature was investigated using gas chromatography-ion mobility spectrometry, resulting in volatile content significantly increasing above 30 ℃. The partial least squares discriminant analysis was conducted to predict the variable importance for the projection (VIP) of volatiles, and 22 volatiles (VIP > 1) were screened. These 22 volatiles were confirmed as key odorants influenced by serving temperature though aroma addition experiments. The findings would provide a reference for the effects of serving temperature on the flavor perception of fermented alcoholic beverages. [ABSTRACT FROM AUTHOR]

• Inoculated raw wheat Qu (IRWQ) is a perfect improvement of traditional wheat Qu. • IRWQ maintained the microbial diversity and enhanced hydrolytic enzyme activities. • IRWQ microbiota is firstly disclosed by single molecule real-time DNA sequencing. • The functional microorganisms in IRWQ was firstly analyzied. • Mould, yeast and bacteria contributed different aspects to IRWQ characters. Inoculated raw wheat Qu (IRWQ), which can be produced with high efficiency and low cost while maintaining stable quality, is a new Qu that has been applied to Huangjiu brewing. In this study, single molecule real-time DNA sequencing technology and culture-dependent methods were combined for the first time to study the microbiota and the function of the principle microorganisms in IRWQ. The glucoamylase, amylase and protease contents of IRWQ were 1.17, 1.55 and 2.87-times greater, respectively, than those of traditional wheat Qu. Like traditional wheat Qu, the main volatile flavor compounds in IRWQ were alcohols; however, the esters content was much higher and the acids content was much lower. Single molecule real-time DNA sequencing technology identified 18 fungal species and 59 bacterial species in IRWQ. Then, 30 species were isolated by culture-dependent methods. These species represented about 80% of the total fungal microbiota and 35% of the total bacteria microbiota. Molds were the main contributors of glucoamylase, amylase and protease activities. Aspergillus flavus had the highest glucoamylase and protease activity. Bacillus subtilis and Bacillus amyloliquefaciens also produced high hydrolytic enzyme activities. Saccharomyces cerevisiae produced the largest amounts of aromatics compounds, alcohols, esters and acids. Aldehydes and ketones are mainly produced by molds. [ABSTRACT FROM AUTHOR]

[Display omitted] • P. pentosaceus , W. paramesenteroides , R. emersonii, B. spectabilis were dominant in Daqu. • Four Saccharopolyspora species were dominant in wheat Qu. • Flavor metabolic pathways in Qu microbiota were reconstructed. • The dominant microbes in Qu may not be the main functional microbes. Daqu and wheat Qu are saccharification and fermenting agents in Chinese huangjiu and baijiu production. This study aimed to investigate the difference between Daqu and wheat Qu in physicochemical indices, microbial communities, functional genes, and the metabolic network of key microbes responsible for flavor synthesis by whole-metagenome sequencing and metabolite analysis. Herein, physicochemical indices indicated that compared with wheat Qu , Daqu exhibited higher protease and cellulase activity and acidity, and lower glucoamylase and amylase enzyme activity. Metagenomic sequencing reveals that although Daqu and wheat Qu community composition have significant differences at species level, they have similar functional genes. Daqu were enriched in Pediococcus pentosaceus , Weissella paramesenteroides , Rasamsonia emersonii and Byssochlamys spectabilis (22.48% of the total abundance), while wheat Qu harbored greater abundances of Saccharopolyspora (54.78%, Saccharopolyspora rectivirgula , Saccharopolyspora shandongensis , Saccharopolyspora hirsuta , Saccharopolyspora spinose , and Saccharopolyspora erythraea). From a functional perspective, the important functions of Daqu and wheat Qu are both amino acid metabolism and carbohydrate metabolism. Meanwhile, a combined analysis among microbiota, functional genes, and dominant flavors indicated S. shandongensis , S. rectivirgula , and S. spinose might be the main contributor to the synthesis of flavor compounds in wheat Qu , while R. emersonii , W. paramesenteroides , Leuconostoc citreum , Leuconostoc mesenteroides , Weissella cibaria and P. pentosaceus may make the greatest contribution to flavor compounds synthesis in Daqu. This study reveals the microbial and functional dissimilarities of Daqu and wheat Qu , and helps elucidating different metabolic roles of microbes during flavor formation. [ABSTRACT FROM AUTHOR]