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This investigation undertook a systematic analysis of two kinds Daqu (Tao-hua qu and Fu-qu) made by same method, but in different seasons (spring and summer). The analysis determined the content of microorganisms, enzyme activity and flavour component of the Daqu. From the results, it was noted that the prokaryotic microbial species present in Daqu were much more complex than the eukaryotic microorganisms; from the results of Operational Taxonomic Units, prokaryotic microorganisms were about 6-8 times greater than eukaryotic microorganisms. With regards to eukaryotic microorganisms, Fu-qu contained a more complex consortium than Tao-hua qu, but Tao-hua qu contained a more complex prokaryotic population than Fu-qu. The saccharification and liquefaction of Daqu were achieved by the mould and a saccharifying enzyme, which was secreted by the mould. The growth temperature of the mould was 20-30 °C and from the analysis results it can be seen that the saccharification and liquefaction of Tao-hua qu produced in the spring was higher than that of Fu-qu produced in the summer. A qualitative analysis of the volatile flavour substances in Daqu was performed using the methods of the NIST data-base and relative retention indices. Approximately 26 kinds of volatile flavour substances were detected in the Tao-hua qu compared with approximately 22 kinds of volatile flavour substances in the Fu-qu. A specific observation of the volatile flavour substances of the two was that Tao-hua qu and Fu-qu had about 13 volatile flavour compounds that were common to both. Copyright © 2016 The Institute of Brewing & Distilling [ABSTRACT FROM AUTHOR]

Gluconacetobacter strains are prominent bacteria during traditional vinegar fermentation. Here, we report a draft genome sequence of Gluconacetobacter sp. strain SXCC-1. This strain was isolated from a fermentation starter (Daqu) used for commercial production of Shanxi vinegar, the best-known vinegar of China. [ABSTRACT FROM AUTHOR]

A two-step extraction method was used to extract proteins from Caragana korshinskii Kom., including a NaOH solution extraction followed by a water extraction. A power-law model, three-site kinetic extraction model, and second-order model were utilized to investigate the mechanism of the water extraction process and the key factors affecting the protein yield. The experimental data fitted well with the three-site kinetic model, indicating that the water extraction process included washing and faster and slower stages. In addition, the slower stage was the rate-limiting step. For the water extraction process, the protein yield was increased by decreasing the particle size, increasing the NaOH concentration, or raising the extraction temperature, among which the extraction temperature was the critical factor for controlling the protein yield. [ABSTRACT FROM AUTHOR]

Steam explosion (SE) was used to pretreat rice straw (RS) and Caragana korshinskii Kom. (CKK). Enzymatic hydrolysis of pretreated RS and CKK, and a pure cellulose (bacterial cellulose, BC) were performed and compared. The characteristics and changes of different substrates during pretreatment and enzymatic hydrolysis were observed. After SE pretreatment, the hemicellulose content of RS and CKK was decreased from 21.7% to 4.9% and 17.9% to 6.2%, respectively. The cellulose percent of RS and CKK was increased to 45.1% and 38.4%, and the enzymatic hydrolysis conversion of cellulose was increased 1.1 times and 0.9 times, respectively. Although the composition and enzymatic yield of different substrates varied, their enzymatic hydrolysis rates showed a similar declining trend during enzymatic hydrolysis. The adsorption capacities of substrates on the enzyme were increased by pretreatment. The enzymatic hydrolysis efficiency was closely related to the enzyme adsorption capacities of substrates at the initial stage (1 h). The BC and SE pretreated RS first adsorbed and subsequently desorbed the enzyme, while the untreated RS and CKK had weak adsorption capacity and formed irreversible adsorption with the enzyme. The changes in crystallinity after enzymatic hydrolysis suggested that there was no direct correlation between the crystallinity and digestibility of cellulose. [ABSTRACT FROM AUTHOR]

Baijiu is a widely consumed spirit usually distilled from fermented sorghum. Here the use of other cereal grains (wheat, corn, rice and barley) is compared with sorghum. The concentration of ethyl acetate in spirit made from sorghum was found to be higher than in the spirits made using other grains, whereas the concentrations of aldehydes and higher alcohols were lower. Based on sensory evaluations, the flavours were more satisfactory when sorghum was used for making Baijiu. Of the other cereals, the flavour from wheat was better than those of corn, rice and barley for making Baijiu. The ester concentration of the spirit made from the rice was low, whereas aldehyde and alcohol contents were high. An abnormal flavour was found in spirits made from corn or barley. Further work with sorghum showed variations in tannin content, and a correlation between the tannin content and brewing performance. When the content of tannin was <1.94%, the ethyl acetate and ethyl octanoate content were positively correlated with tannin content. In contrast, the ethyl lactate and higher fatty acid ethyl esters content were negatively correlated with tannin content. The results of flavour analysis and sensory evaluation indicated that the ideal sorghum tannin content for producing Baijiu was between 1.0 and 2.0%. Copyright © 2017 The Institute of Brewing & Distilling [ABSTRACT FROM AUTHOR]