Find in Library

Chinese Baijiu is principally produced through a spontaneous fermentation process, which involves complex microorganism communities. Among them, yeasts and lactic acid bacteria (LAB) are important communities. The study examined the isolated strains from fermented grains of Baijiu regarding their activity of &#945;-amylase and glucoamylase, ethanol tolerance, glucose utilization, as well as metabolite production in the process of laboratory-scale sorghum-based fermentation. Selected strains (<i>Saccharomycopsis fibuligera</i> 12, <i>Saccharomyces cerevisiae</i> 3, and <i>Pediococcus acidilactici</i> 4) were blended in different combinations. The influence of selected strains on the metabolic variation in different semi-solid fermentations was investigated by gas chromatography&#8722;mass spectrometry (GC&#8722;MS) accompanied by multivariate statistical analysis. According to the principal component analysis (PCA), the metabolites produced varied in different mixtures of pure cultures. <i>S. fibuligera</i> produced various enzymes, particularly &#945;-amylase and glucoamylase, and exhibited a better performance compared with other species regarding the ability to convert starch to soluble sugars and positively affect the production process of volatile compounds. <i>S. cerevisiae</i> had a high fermentation capacity, thereby contributing to substrates utilization. Lactic acid bacteria had a good ability to produce lactic acid. This study attaches importance to the special functions of <i>S. fibuligera</i>, <i>S. cerevisiae</i>, and <i>P. acidilactici</i> in Chinese Baijiu making, and investigates their metabolic characteristics in the process of lab-scale semi-solid fermentation.