Identification of colloidal haze protein in Chinese rice wine (Shaoxing Huangjiu) mainly by matrix-assisted laser ionization time-of-flight mass spectrometry

Analyzing the contribution of top-down and bottom-up methods to the construction of synthetic microbial communities in Jiuyao

The construction of synthetic microbial communities is a crucial strategy for improving the stability of microbial populations and the quality of fermented foods. Jiuyao, an essential saccharification and fermentation starter in Huangjiu production, was the focus of this study. Using metagenomics combined with culture-dependent methods, we identified 11 microbial species involved in Huangjiu fermentation. Through metagenomic analysis and simulated fermentation, Rhizopus delemar, Rhizopus microspores, Rhizopus stolonife, Rhizopus azygosporus, Saccharomycopsis fibuligera, Saccharomyces cerevisiae, Wickerhamomyces anomalus and Pediococcus pentosaceus were determined to be the core microbial species driving the Jiuyao fermentation process. A synthetic microbial community was constructed based on these species, successfully reproducing the flavor and sensory qualities of Huangjiu while enhancing fermentation efficiency. This study provides valuable insights into the functional roles of Jiuyao-associated microbes and offers a framework for improving microbial community stability and fermentation quality in Huangjiu production.

An efficient method for maintaining clarity and forming tight and low amount of sediment in pomegranate juice during storage: Enzymatic hydrolysis with "tannase + lactonase + papain"

Turbidity and sediment formation in pomegranate juice (PJ) is a consequence of the interaction between tannins and proteins. The aim of this study was to disrupt this interaction by enzymatic hydrolysis of tannins ["tannase," "lactonase (R-PON-1)"] and proteins (papain). The effect of enzymatic treatments on sediment/turbidity was studied throughout storage (20 °C). Low and tight sediment formation was only possible when protein and tannins were hydrolysed together. In "tannase + R-PON-1 + papain" treated PJ, turbidity decreased after storage and the lowest and tightest sediment was also detected (p < 0.05). The strongest correlations were found between the "prolamin/punicalagin-2" ratio and turbidity (r = 0.997) and tight sediment formation (r = -0.964). This ratio should be 4.38 ± 0.07 to completely eliminate sediment formation in PJ. To achieve this ratio, punicalagin-2 should be added to PJ. This study is the first to show that punicalagin-2 should be added to PJ to produce a clear and sediment-free PJ, contrary to previous clarification methods.

RSM optimization of fermentation technology of yellow wine produced from Millets rice (containing Daylily and Agaricus blazei Murr) and analysis of volatile aroma constituents and amino acid contents by GC-MS and HPLC

The fermentation process was carried out with varied input variables, and all the models showed significant p-values for interaction of variance (<0.05). Millet rice yellow wine with ethanol yield of 15.68%, v/v was produced at an optimized temperature of 32 °C, yeast addition quantity of 9%, and time of 41 days. The volatile compounds in millet rice wine were analyzed by gas chromatography coupled with mass spectrometry (GC/MS). Amino acid components in yellow wines were analyzed by high performance liquid chromatography (HPLC). Ten, twelve and sixteen volatile compounds were detected in wines in fermentation time of 41, 55 and 70 days, respectively. HPLC shows that the content of amino acids in rice wine is not only the highest, but also has 20 kinds, including 8 kinds of essential amino acids for human body. The difference in volatile components and amino acids composition greatly contribute to the flavor of the wine.