Physicochemical properties of red millet, a novel Chinese rice wine brewing material

HighlightsThe TS-PEF diminished the color change compared to individual treatments.The concentration of Fe, Cr, and Ni increased after the treatments of PEF and TS-PEF.The volatile flavor compounds decreased after the treatment of TS and TS-PEF.Abstract. Chinese rice wine (CRW) is a traditional wine prevalent in East Asia. In current industrial production of bottled CRW, an additional thermal pasteurization is required at the bottling stage to extend the shelf life of the product, and this thermal treatment results in quality degradation and even carcinogen formation. In our previous studies, non-thermal technologies such as pulsed electric fields (PEF), thermosonication (TS), and their combination (TS-PEF) have been shown to significantly inactivate Saccharomyces cerevisiae in CRW as an alternative to thermal pasteurization of bottled wine. However, studies of their effects on the quality of CRW are very limited. In this study, we compared the physicochemical properties of CRW treated by pasteurization, PEF, TS, and TS-PEF. The results showed that the basic physicochemical indicators of CRW (total sugar, non-sugar solids, total acidity, amino acid nitrogen, and pH) did not change significantly after all these treatments. The TS-PEF treatment reduced the total color difference caused by the TS or PEF treatments. However, corrosion of the electrodes during PEF and TS-PEF treatment caused a significant increase in iron, chromium, and nickel concentrations. In addition, volatile flavor compounds, such as alcohols, esters, acids, and aldehydes, were reduced much more after TS and TS-PEF treatment than after pasteurization and PEF. Further research is needed on minimizing the negative impacts of these new technologies on the flavor of CRW in the context of effective sterilization. Keywords: Chinese rice wine, Metal ion, Physicochemical properties, Pulsed electric fields, Ultrasound, Volatile flavor compounds.

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Study on relationship between bacterial diversity and quality of Huangjiu (Chinese Rice Wine) fermentation

Food Science & Nutrition ◽

10.1002/fsn3.2369 ◽

2021 ◽

Author(s):

Guangfa Xie ◽

Huajun Zheng ◽

Zheling Qiu ◽

Zichen Lin ◽

Qi Peng ◽

...

Keyword(s):

Bacterial Diversity ◽

Wine Fermentation ◽

Rice Wine ◽

Chinese Rice Wine

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iTRAQ-based proteomic analysis reveals the molecule mechanism of reducing higher alcohols in Chinese rice wine by nitrogen compensation

Annals of Microbiology ◽

10.1186/s13213-020-01611-7 ◽

2021 ◽

Vol 71 (1) ◽

Author(s):

Guidong Huang ◽

Hong Ren ◽

Ali Wang ◽

Xinran Wan ◽

Ziying Wu ◽

...

Keyword(s):

Molecular Mechanism ◽

Carbon Metabolism ◽

Proteomic Analysis ◽

Metabolic Flux ◽

Quantitative Polymerase Chain Reaction ◽

Higher Alcohols ◽

Rice Wine ◽

Chinese Rice Wine ◽

Higher Alcohol ◽

Amino Acid Synthesis

Abstract Purpose Higher alcohol is a by-product of the fermentation of wine, and its content is one of the most important parameters that affect and are used to appraise the final quality of Chinese rice wine. Ammonium compensation is an efficient and convenient method to reduce the content of higher alcohols, but the molecule mechanism is poorly understood. Therefore, an iTRAQ-based proteomic analysis was designed to reveal the proteomic changes of Saccharomyces cerevisiae to elucidate the molecular mechanism of ammonium compensation in reducing the content of higher alcohols. Methods The iTRAQ proteomic analysis method was used to analyze a blank group and an experimental group with an exogenous addition of 200 mg/L (NH4)2HPO4 during inoculation. The extracted intracellular proteins were processed by liquid chromatography-mass spectrometry and identified using bioinformatics tools. Real-time quantitative polymerase chain reaction was used to verify the gene expression of differentially expressed proteins. Results About 4062 proteins, including 123 upregulated and 88 downregulated proteins, were identified by iTRAQ-based proteomic analysis. GO and KEGG analysis uncovered that significant proteins were concentrated during carbohydrate metabolism, such as carbon metabolism, glyoxylate, and dicarboxylate metabolism, pyruvate metabolism, and the nitrogen metabolism, such as amino acid synthesis and catabolism pathway. In accordance with the trend of differential protein regulation in the central carbon metabolism pathway and the analysis of carbon metabolic flux, a possible regulatory model was proposed and verified, in which ammonium compensation facilitated glucose consumption, regulated metabolic flow direction into tricarboxylic acid, and further led to a decrease in higher alcohols. The results of RT-qPCR confirmed the authenticity of the proteomic analysis results at the level of gene. Conclusion Ammonium assimilation promoted by ammonium compensation regulated the intracellular carbon metabolism of S. cerevisiae and affected the distribution of metabolic flux. The carbon flow that should have gone to the synthesis pathway of higher alcohols was reversed to the TCA cycle, thereby decreasing the content of higher alcohols. These findings may contribute to an improved understanding of the molecular mechanism for the decrease in higher alcohol content through ammonium compensation.

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