Search

Summary: Mixed starter of pure mould and yeast was designed to circument the problem of flavour characteristics in rice wine. The result underlined that the mixed starter (Q7) made by simultaneous inoculation of Rhizopus oryzae, Saccharomyces cerevisiae, Wickerhamomyces anomalus and Candida glabrata had the highest contents of α‐amylase (8.02 ± 0.96 U/g) and sensory scoring (92.05 ± 2.24), presenting relatively strong flower‐aroma, wine‐aroma, Qu‐aroma and rice‐aroma. Meanwhile, the total concentration of flavour compounds in rice wine (RQ, 125.828 mg L−1) obtained from rice fermentation using Q7 were better than the commercially available rice wine (SS, 125.828 mg L−1). The E‐nose analysis showed that the flavour components in RQ differed dramatically from SS. The E‐tongue results indicated that the sourness, sweetness and umami aftertaste were greatly higher in RQ, and the bitterness and astringency are lower compared with SS. This study provided a method to improve the flavour and quality of rice wine. [ABSTRACT FROM AUTHOR]

Ginkgo seed is a kind of food and medicine homologous goods. It is a feasible method to use Saccharomyces cerevisiae and Non- Saccharomyces yeast to ferment ginkgo rice wine (GRW) to remove the bitter taste and retain the biological activity. In order to better explore the formation of the unique flavor and taste of GRW, the volatile flavor compounds and sensory properties of GRWs fermented at different time were analyzed by GC-MS, GC-IMS and electronic sensory evaluation techniques. In addition, the changes of phenols in GRW were determined by LC-MS, and the antioxidant activity was dynamically monitored. GC-MS analysis showed the content of ethyl laurate, isoamyl acetate, ethyl heptanoate, 1-pentanol, ethanol and 1-propanol increased significantly with the progress of fermentation, among which ethyl acetate (OAV = 23.0), ethyl heptanoate (OAV = 44.4) and isoamyl acetate (OAV = 34.7) were the key flavor compounds of GRW at 60 h. GC-IMS analysis suggested some alcohols and ketones were significantly enriched at 60 h, including 2-pentanone, acetone, 1-butanol, 1-hexanol. Electronic sensory technology showed GRW at 60 h had strong mellow and fruity aroma due to benzoic acid, butyric acid and 2-methylbutyric acid. The bitterness and umami intensity in GRW gradually decreased, while the astringency and aftertaste increased. Furthermore, LC-MS results indicated the types of phenols increased, including quinic acid, shikimic acid, sorbic acid, etc., which significantly improved the antioxidant activity of GRW. Together, the flavor quality and biological activity of GRW had been effectively improved through microbial fermentation, which indicated that GRW had potential market prospects. [Display omitted] • The intensity of bitterness of ginkgo rice wine (GRW) decreased by fermentation. • S. cerevisiae and W. anomalus enhanced the flavor and antioxidant activity of GRW. • The combination of GC-MS and GC-IMS provided a more comprehensive flavor analysis. • Key flavor compounds in GRW were 1-pentanol, ethyl heptanoate and isoamyl acetate. • The types and content of phenolic compounds in GRW increased after fermentation. [ABSTRACT FROM AUTHOR]

Highland barley alcoholic drink (HBD), as one of the most typical rice wines in Qinghai-Tibet plateau area, is generally brewed by adding Jiuqu to highland barley. However, the flavor and quality of HBD fermented with Jiuqu in various plateau regions are different. This study elucidated the potential correlation between the microbial community, physicochemical properties of five traditional plateau Jiuqu, namely Hongxin1 (HX1), Hongxin2 (HX2), Huairang (HR), Hoarfrost gypsophila (HG) and Tibet Qu (TQ), and volatile flavor compounds of HBD. Based on high-throughput sequencing (HTS) technology and LEfSe analysis, it was found that the bacteria and fungi of the five traditional plateau Jiuqu were quite different. Differential microorganisms were Weissella and Pichia in HX1, Lactococcus and Kazachstania in HR, Acetobacter and Rhizopus in TQ. Besides, HX1 and HX2 had higher esterification power, TQ had the highest fermentation power while HR had the lowest enzymatic properties. Finally, RDA and Pearson correlation analysis showed that esterification power and moisture content had positive effects on Lactobacillus , fermentation power and saccharification power were highly positively correlated with Pantoea and Rhizopus , but negatively correlated with Aspergillus. In flavor analysis, Rhizopus, Acetobacter were found positively correlated with alcohols and acids, which contributed to the formation of volatile flavor compounds, Lactobacillus_sanfranciscensis and Lactobacillus_sakei were positively correlated with phenolic compounds. This study showed that the flavor of HBD was seriously affected by the microbiota in Jiuqu, which could help to develop new fortified starter to improve the quality of HBD. [Display omitted] • Pearson correlation analysis was conducted on the microbes of different plateau Jiuqu and the aroma components of HBD. • The difference in the microbial and enzyme properties of plateau Jiuqu led to great differences in the flavor of HBD. • Pantoea contributed to esterification, while Rhizopus contributed to fermentation and saccharification. • Acetobacter and Rhizopus were positively correlated with main flavors in HBD. • Key flavor compounds in HBD were phenethyl alcohol, ethanol, acetic acid and ethyl acetate. [ABSTRACT FROM AUTHOR]