Rice Wine Brewing Research Articles

Mechanism of Polygonum hydropiper reducing ethyl carbamate in Chinese rice wine (Huangjiu) brewing

Polygonum hydropiper (PH) is a rich source of active compounds and serves as a pivotal ingredient in Chinese rice wine (Huangjiu) production. This study investigates the impact of PH and Polygonum hydropiper extract (PHE) on ethyl carbamate (EC) production during Huangjiu fermentation. Our findings reveal that PH enhances the relative abundance of Bacillus subtilis in Huangjiu fermentation, thereby facilitating its interaction with Saccharomyces cerevisiae. Furthermore, PH modulates the urea metabolism of S. cerevisiae. In the PH-B. subtilis-S. cerevisiae fermentation system, the expression of DUR1,2 and DUR3 genes in S. cerevisiae is upregulated. This augmentation leads to increased urea uptake and metabolism by S. cerevisiae in the fermentation broth, subsequently reducing the urea concentration in the fermentation medium (The EC content in the CK group was approximately 355.55 % and 356.05 % higher than those in the PH and PHE groups, respectively). Consequently, PH demonstrates promise in reducing the EC concentration of Huangjiu, offering a novel approach to enhance the safety of Huangjiu consumption.

Denovo Production of Resveratrol by Engineered Rice Wine Strain Saccharomyces cerevisiae HJ08 and Its Application in Rice Wine Brewing.

Resveratrol is a plant-derived polyphenolic compound with numerous biological activities and health-promoting properties. Rice wine is a popular traditional alcoholic beverage made from fermented rice grains, and widely consumed in Asia. To develop resveratrol-enriched rice wine, a heterologous resveratrol biosynthesis pathway was established by integrating the 4-coumaroyl-CoA ligase (Pc4CL) and the stilbene synthase (VvSTS) from Petroselinum crispum and Vitis vinifera at the δ locus sites of industrial rice wine strains Saccharomyces cerevisiae HJ. The resulting S. cerevisiae HJ01 produced a level of 0.6 ± 0.01 mg/L resveratrol. Next, the resveratrol production was increased 16.25-fold through employing the fused protein Pc4CL::VvSTS with a rigidly linked peptide (TPTP, EAAAK). Then, the strains were further modified by removing feedback inhibition of tyrosine through point mutation of ARO4 and ARO7, which integrated at the rDNA region of strain HJ03, and generated strain HJ06, HJ07, and HJ08. Subsequently, the highest resveratrol titer (34.22 ± 3.62 mg/L) was obtained by optimizing fermentation time and precursor addition amount. Finally, resveratrol content of rice wine fermented with strain HJ08 was 2.04 ± 0.08 mg/L and 1.45 ± 0.06 mg/L with or without the addition of 400 mg/L tyrosine after 7 days fermentation.

Screening, identification, and characterization of molds for brewing rice wine: Scale-up production in a bioreactor.

Rice wine, well known for its unique flavor, rich nutritional value, and health benefits, has potential for extensive market development. Rhizopus and Aspergillus are among several microorganisms used in rice wine brewing and are crucial for determining rice wine quality. The strains were isolated via Rose Bengal and starch as a combined separation medium, followed by oenological property and sensory evaluation screening. The strain exhibiting the best performance can be screened using the traditional rice wine Qu. The strains YM-8, YM-10, and YM-16, which exhibited strong saccharification and fermentation performance along with good flavor and taste, were obtained from traditional rice wine Qu. Based on ITS genetic sequence analysis, the YM-8, YM-10, and YM-16 strains were identified as Rhizopus microsporus, Rhizopus arrhizus, and Aspergillus oryzae. The optimum growth temperature of each of the three strains was 30°C, 32°C, and 30°C, and the optimum initial pH was 6.0, 6.5, and 6.5, respectively. The activities of α-amylase, glucoamylase, and protease of YM-16 were highest at 220.23±1.88, 1,269.04±30.32, and 175.16±1.81 U/g, respectively. The amino acid content of rice wine fermented in a 20-L bioreactor with the three mold strains was higher than that of the control group, except for arginine, which was significantly lower than that of the control group. The total amino acid content and the total content of each type of amino acid were ranked as YM-16 > YM-8 > YM-10 > control group, and the amino acid content varied greatly among the strains. The control group had a higher content, whereas YM-8 and YM-16 had lower contents of volatile aroma components than the control group and had the basic flavor substances needed for rice wine, which is conducive to the formation of rice wine aroma. This selected strain, YM-16, has strong saccharification and fermentation ability, is a rich enzyme system, and improves the flavor of rice wine, thereby demonstrating its suitability as a production strain for brewing.

Genome-wide transcriptome analyses reveal changes in glutathione-overproducing yeast obtained by ARTP mutagenesis for rice wine brewing

The atmospheric and room temperature plasma (ARTP) technique efficiently enhances yeast glutathione (GSH) yield. This study focused on obtaining a GSH over-producing strain, Saccharomyces cerevisiae SCZ40, through mutagenesis and stability testing. SCZ40 exhibited a remarkable 71.1% increase in GSH content during rice wine fermentation. Scanning electron microscopy (SEM) and whole-genome sequencing identified ARTP-induced changes in cell morphology and alterations in the protein-serine/threonine kinase and isocitrate dehydrogenase pathways linked to GSH synthesis. Transcriptomic analysis revealed 507 differentially expressed genes, highlighting the impact of ARTP on S. cerevisiae. Up/down-regulated genes associated with glycolysis/gluconeogenesis suggested a shift in glucose distribution favoring the pentose phosphate pathway and positively influencing GSH production. Pathway analysis further elucidated changes in glycolysis/gluconeogenesis, tricarboxylic acid cycle (TCA), and GSH biosynthesis pathways. Validation through quantitative real-time polymerase chain reaction (qRT-PCR) confirmed RNA-seq data reliability.

In-situ substitution and community dynamics modeling for enhanced safety in Chinese rice wine brewing

This research paper focuses on the application of the “Design-Build-Test-Learn” framework to design and evaluate a synthetic microbial community aimed at studying the impact of Lactic Acid Bacteria (LAB) interactions and fitness on the formation of biogenic amines (BAs) in Chinese rice wine (CRW). The study reveals a close correlation between the assembly model of LAB and the accumulation of BAs in CRW, and multiple interactions were observed between amine-producing and non-amine-producing LAB, including commensalism, amensalism, and competition. The commensalism among amine-producing LAB was found to promote BAs accumulation through metabolic cross-feeding of amino acids. Moreover, the higher-order interaction community was designed to regulate the BAs formation effectively. For instance, the interference of Lactiplantibacillus plantarum (ACBC271) resulted in the elimination of amine-producing LAB viability, resulting in a 22% decrease (not exceeding 43.54 mg/L) in the total amount of BAs. Simulation of community dynamics models further suggests that LAB with quantitative social interactions can effectively control LAB accumulation in CRW by forecasting fluctuation in BAs generation through fitness competition and metabolic interference. Overall, this study provides valuable insights into the complex interaction networks within microbial communities in traditional fermentation ecosystems. It also proposes a novel approach for quality control of nitrogen food safety factors in fermented foods.

The regulatory effects of microbial community on the formation of higher alcohols and volatile flavor components in Hongqu rice wine brewing

The contents of higher alcohols (HAs) and volatile components produced by microbial metabolism largely determine the drinking comfort and flavor quality of Hongqu rice wine. The purpose of this study was to compare the differences of volatile flavor profile and microbial community in the brewing process of Hongqu rice wines with low and high HAs content (LHA and HHA). The results showed that the main HAs in Hongqu rice wine were isobututyl alcohol, isoamyl alcohol, phenylethyl alcohol, and the total content of HAs in HHA (749.07 ± 20.47 mg/L) was much higher than that in LHA (407.61 ± 20.80 mg/L). Multivariate statistical analysis and visualization showed that the volatile flavor characteristics of HHA and LHA were significantly different, and the contents of ethyl esters, medium- and long-chain fatty acids in HHA were higher than those in LHA. Microbiome analysis based on metagenomic sequencing indicated that fermentation starter has significant effect on the composition of microbial community during Hongqu rice wine brewing. Microbial species such as Cronobacter sakazakii, Weissella paramesenteroides, Klebsiella pneumoniae, Aspergillus niger, Millerozyma farinosa and Rhizopus delemar were significantly enriched in HHA brewing, while Pediococcus pentosaceus, Lactobacillus curvatus, Leuconostoc pseudomesenteroides and Leuconostoc mesenteroides were significantly enriched in LHA brewing. Furthermore, the potential relationships between the key microbial species and characteristic volatile components were revealed through correlation heatmap analysis. Bioinformatical analysis revealed that the abundances of microbial genes encoding enzymes involved in HAs metabolism were higher in HHA than LHA, but the gene abundance of phenylacetaldehyde dehydrogenase in LHA was significantly higher than that in HHA, which could limit the formation of HAs during Hongqu rice wine brewing. Collectively, this study provides important scientific data for enhancing the flavor quality of Hongqu rice wine, and lays a solid foundation for the healthy development of Hongqu rice wine industry.

Effects of different lactic acid bacteria on the characteristic flavor profiles of Chinese rice wine.

It has been well accepted that lactic acid bacteria (LAB) are the main bacterial genera present during the brewing of Chinese rice wine (CRW). LAB plays a decisive role in the flavor quality of CRW; however, its application in CRW has previously been overlooked. Therefore, effects of different LAB as co-fermenter on the flavor characteristics of CRW were investigated. Co-fermentation of LAB increased the utilization rate of reducing sugar, concentration of lactic acid, amino acid nitrogen and total acidity, as well as the content of volatile flavor compounds. Different LAB doses had little effect on the flavor profiles of CRW, but the species of LAB greatly affected the flavor characteristic. The flavor of CRW co-fermented with Lactococcus lactis was characterized by long-chain fatty acid ethyl esters, while co-fermentation with Weissella confusa highlighted the ethyl esters of low molecular weight and short carbon chains in the resultant CRW. Alcohol compounds were dominant in the CRW co-fermented using Pediococcus pentosaceus. The co-fermentation of LAB increased the number of volatile flavor compounds, especially esters. LAB exhibited great potential in the application of CRW industry to enrich the flavor characteristics and enhance the flavor diversity of the final product. © 2023 Society of Chemical Industry.

Metagenomic Insights into the Regulatory Effects of Microbial Community on the Formation of Biogenic Amines and Volatile Flavor Components during the Brewing of Hongqu Rice Wine.

As one of the typical representatives of Chinese rice wine (Huangjiu), Hongqu rice wine is produced with glutinous rice as the main raw material and Hongqu as the fermentation starter. The complex microbial flora in the brewing process may have a great influence on the formation of the flavor quality and drinking safety of Hongqu rice wine. Previous studies have shown that high biogenic amine (BA) content in rice wine has potential physiological toxicity and has become a bottleneck problem restricting the development of the rice wine industry. This study aimed to evaluate the regulatory effects of the microbial community on the formation of BAs and volatile flavor components during the brewing of Hongqu rice wine. The results demonstrated that histamine, putrescine, cadaverine, tyramine, tryptamine, spermine, and spermidine were the main BAs in Hongqu rice wine. The contents of putrescine, cadaverine, histamine, tyramine, and spermidine in Hongqu rice wine of HBAs (with higher BAs content) were significantly higher than those in LBAs (with lower BAs content). GC-MS testing results showed that there were significant differences in the composition of volatile organic compounds (VOCs) between HBAs and LBAs. Among them, VOCs such as 2-methoxy-4-vinylphenol, ethyl caprate, phenethyl acetate, ethyl lactate, ethyl myristate, ethyl palmitate, ethyl n-octadecanoate, ethyl oleate, and ethyl linoleate were identified as the characteristic volatile components with significant differences between HBAs and LBAs. Microbiome analysis based on metagenomic sequencing revealed that unclassified_g_Pantoea, Klebsiella pneumoniae, Panobacter disperse, unclassified_f_Enterobacteriaceae, Leuconostoc mesenteroides, and Saccharomyces cerevisiae were the dominant microbial species in the HBA brewing process, while Weissella confuse, Pediococcus acidilactici, Saccharomyces cerevisiae, and Aspergillus niger were the dominant microbial species in the LBA brewing process. Furthermore, correlation heatmap analysis demonstrated that BAs were positively related to Lactobacillus curvatus, Lactococcus lactis, and Leuconostoc mesenteroides. Bioinformatical analysis based on the KEGG database revealed that the microbial genes encoding enzymes involved in BAs' synthesis were more abundant in HBAs, and the abundances of microbial genes encoding enzymes related to BAs' degradation and the metabolism of characteristic volatile components were higher in LBAs. Overall, this work provides important scientific data for enhancing the flavor quality of Hongqu rice wine and lays a solid foundation for the healthy development of the Hongqu rice wine industry.

Major Active Metabolite Characteristics of Dendrobium officinale Rice Wine Fermented by Saccharomyces cerevisiae and Wickerhamomyces anomalus Cofermentation.

Rice, supplemented with Dendrobium officinale, was subjected to cofermentation using Saccharomyces cerevisiae FBKL2.8022 (Sc) and Wickerhamomyces anomalus FBKL2.8023 (Wa). The alcohol content was determined with a biosensor, total sugars with the phenol-sulfuric acid method, reducing sugars with the DNS method, total acids and total phenols with the colorimetric method, and metabolites were analyzed using LC-MS/MS combined with multivariate statistics, while metabolic pathways were constructed using metaboAnalyst 5.0. It was found that the quality of rice wine was higher with the addition of D. officinale. A total of 127 major active substances, mainly phenols, flavonoids, terpenoids, alkaloids, and phenylpropanoids, were identified. Among them, 26 substances might have been mainly metabolized by the mixed-yeasts fermentation itself, and 10 substances might have originated either from D. officinale itself or from microbial metabolism on the newly supplemented substrate. In addition, significant differences in metabolite could be attributed to amino acid metabolic pathways, such as phenylalanine metabolism and alanine, aspartate, and glutamate metabolism. The characteristic microbial metabolism of D. officinale produces metabolites, which are α-dihydroartemisinin, alantolactone, neohesperidin dihydrochalcone, and occidentoside. This study showed that mixed-yeasts cofermentation and fermentation with D. officinale both could increase the content of active substances in rice wine and significantly improve the quality of rice wine. The results of this study provide a reference for the mixed fermentation of brewer's yeast and non-yeast yeasts in rice wine brewing.

Levilactobacillus brevis with High Production of Putrescine Isolated from Blue Cheese and Its Application.

Polyamine intake has been reported to help extend the lifespan of animals. Fermented foods contain high concentrations of polyamines, produced by fermenting bacteria. Therefore, the bacteria, isolated from fermented foods that produce large amounts of polyamines, are potentially used as a source of polyamines for humans. In this study, the strain Levilactobacillus brevis FB215, which has the ability to accumulate approximately 200 µM of putrescine in the culture supernatant, was isolated from fermented foods, specifically the Blue Stilton cheese. Furthermore, L. brevis FB215 synthesized putrescine from agmatine and ornithine, which are known polyamine precursors. When cultured in the extract of Sakekasu, a byproduct obtained during the brewing of Japanese rice wine containing high levels of both agmatine and ornithine, L. brevis FB215 grew to OD600 = 1.7 after 83 h of cultivation and accumulated high concentrations (~1 mM) of putrescine in the culture supernatant. The fermentation product also did not contain histamine or tyramine. The Sakekasu-derived ingredient fermented by the food-derived lactic acid bacteria developed in this study could contribute to increasing polyamine intake in humans.

Lactobacillus plantarum F25‐4 assisted rice soaking reduces the cooking strength of japonica rice for Chinese rice wine brewing

SummaryThis study investigated the effect of Lactobacillus plantarum F25‐4 assisted rice soaking (LAS) on the cooking properties of japonica rice used for Chinese rice wine (CRW) production. The effects of LAS and natural soaking were compared based on the chemical composition, thermal characteristics, infrared spectroscopy and sodium dodecyl sulphate‐polyacrylamide gel electrophoresis of rice flour. After LAS, the protein content of the rice was reduced by 17.63%, and the initial temperature (To), peak temperature (Tp) and conclusion temperature (Tc) were reduced by 36.86%, 17.89% and 1.61%, respectively, as revealed by differential scanning calorimetry analysis. The Zeta (ζ) potential value changed from −8.75 mV to −3.99 mV, and the minimum cooking time was reduced by 40% to only 15 min. The viscoelasticity of LAS rice increased after gelatinisation, as confirmed by confocal laser scanning microscope images. The glutelin precursor of the LAS rice disappeared, and the disorder of protein secondary structure increased, but there was no significant difference in the starch crystal area. LAS effectively improved the cooking properties of rice by changing the protein configuration on the surface of starch granules and reducing protein adsorption, leading to increased starch water absorption and decreased rice gelatinisation temperature. Our research suggests that LAS can reduce the cooking temperature of rice in CRW production, thus saving steam consumption during cooking.

Correlation between the microbial community and ethyl carbamate generated during Huzhou rice wine fermentation

Ethyl carbamate (EC) is a potential carcinogen that is mainly produced by the spontaneous reaction between urea and ethanol during rice wine brewing. Huzhou rice wine (HZRW) is a traditional Chinese rice wine, but the correlation between its urea content and the microbial communities present during the fermentation process has not yet been evaluated. In this study, high-throughput sequencing technology was used to monitor the microbial community composition of HZRW in the different fermentation stages. The correlations between the microbial community and the physical and chemical properties and EC, urea and arginine contents were evaluated using the redundancy analysis (RDA) method. The metabolic profiles of key genes in the arginine and urea metabolic pathways were obtained via phylogenetic investigation of the communities by reconstruction of unobserved states (PICRUSt). The results showed that the fungal genera Saccharomyces, Issatchenkia, Torulaspora and Rhizopus were dominant during the fermentation of HZRW. Weissella and Acinetobacter were the dominant bacterial genera in the early stage, while Weissella, Staphylococcus, Leuconostoc and Streptophyta were the dominant bacterial genera in the late stage. Urea and arginine were positively correlated with Saccharomyces, Lactobacillus and Staphylococcus. In addition, the dominant genera of both fungi and bacteria were involved in the metabolism of arginine and urea. Finally, the relationships between the dominant microorganisms and key genes of the arginine and urea metabolic pathways were established. The obtained results are helpful in better understanding the mechanisms of metabolism of arginine and urea during rice wine fermentation and therefore improving the safety profile of rice wine.

Evaluation of six commercial koji on the formation of biogenic amines and higher alcohols in rice wine

Commercial koji are increasingly used as the microbial inoculum in the production of rice wine. This study reports on the use of six commercial koji on rice wine brewing and shows that the microbial composition varied significantly among the different koji. Of the koji, AQ (An Qi) and YB (Yi Bin) contained fewer microflora but exhibited higher starch degradation and wine production efficiency. The Two-way Orthogonal PLS model and Pearson correlation analysis suggests that the presence of biogenic amines in rice wine was related to contaminating microorganisms in the koji including Lactobacillus, Kosakonia, Pantoea, Ralstonia, Kosakonia and Pantoea. The formation of higher alcohols is related to Saccharomyces species. Screening of beneficial yeasts with low production of higher alcohols and avoiding contamination by unwanted bacteria are suggested for improving the quality of rice wine. © 2022 The Institute of Brewing & Distilling.

Effects of the microbial community on the formation of volatile compounds and biogenic amines during the traditional brewing of Hongqu rice wine

As a typical representative of Chinese rice wine (Huangjiu), Hongqu rice wine is famous for its red color, mellow taste and strong fragrance. However, due to the open brewing environment and traditional fermentation technology, there are some safety risks in traditional brewed Hongqu rice wine, such as a certain amount of biogenic amines. In this study, the dynamic changes and the differences of microbial communities and volatile flavor components between two types of Hongqu rice wine with high and low biogenic amine contents (LBAW and HBAW) during the traditional brewing were systematically investigated. The results showed that the total biogenic amine contents in LBAW and HBAW were 20.91 and 69.06 mg/L, respectively. The contents of putrescine, cadaverine, spermine and spermidine in HBAW were significantly higher than those in LBAW, and it was noteworthy that spermine content in HBAW was 17.62 mg/L, which was not detected in LBAW. In addition, the volatile flavor characteristics of the two kinds of Hongqu rice wine were obviously different. The contents of acetophenone, n-butyl butanoate and benzothiazole were obviously higher in HBAW, while the contents of isoamyl acetate, ethyl lactate, ethyl caprate and phenylethyl alcohol were significantly higher in LBAW. High-throughput sequencing of 16S/ITS amplicon revealed that Weissella, Kosakonia, Pantoea, Monascus, Saccharomyces and Millerozyma were the predominant microbial genera during the traditional brewing of HBAW, while Weissella, Kosakonia, Monascus, Saccharomyces and Issatchenkia were the predominant microbial genera during the traditional brewing of LBAW. Correlation analysis revealed that biogenic amines were significantly negatively correlated with unclassified_o_Saccharomycetales, Cyberlindnera, Zygoascus, Aspergillus and Acinetobacter, but positively correlated with Lactobacillus, Pediococcus, Millerozyma and Apiotrichum. In addition, we also found that Lactobacillus, Pediococcus and Saccharomyces were significantly positively correlated with most of the volatile flavor components, while Candida, Trichosporon and Monascus were significantly negatively correlated with most of the volatile flavor components. In addition, bioinformatical analysis based on PICRUSt demonstrated that the key enzymes for biogenic amine biosynthesis were more abundant in the microbial community of HBAW than LBAW. These findings demonstrate that the formations of volatile flavor and biogenic amines in Hongqu rice wine are influenced by microbial community during the fermentation. This work facilitates scientific understanding of the formation mechanism of biogenic amines, and may be useful to develop effective strategies to improve the quality of Hongqu rice wine.

Pediococcus acidilactici FZU106 alleviates high-fat diet-induced lipid metabolism disorder in association with the modulation of intestinal microbiota in hyperlipidemic rats

Probiotics have been proved to have beneficial effects in improving hyperlipidemia. The purpose of the current research was to investigate the ameliorative effects of Pediococcus acidilactici FZU106, isolated from the traditional brewing of Hongqu rice wine, on lipid metabolism and intestinal microbiota in high-fat diet (HFD)-induced hyperlipidemic rats. Results showed that P. acidilactici FZU106 intervention obviously inhibited the abnormal increase of body weight, ameliorated serum and liver biochemical parameters related to lipid metabolism and oxidative stress. Histopathological evaluation also showed that P. acidilactici FZU106 could significantly reduce the excessive lipid accumulation in liver caused by HFD-feeding. Furthermore, P. acidilactici FZU106 intervention significantly increased the short-chain fatty acids (SCFAs) levels in HFD-fed rats, which was closely related to the changes of intestinal microbial composition and metabolism. Intestinal microbiota profiling by high-throughput sequencing demonstrated that P. acidilactici FZU106 intervention evidently increased the proportion of Butyricicoccus, Pediococcus, Rothia, Globicatella and [Eubacterium]_coprostanoligenes_group, and decreased the proportion of Corynebacterium_1, Psychrobacter, Oscillospira, Facklamia, Pseudogracilibacillus, Clostridium_innocuum_group, Enteractinococcus and Erysipelothrix in HFD-fed rats. Additionally, P. acidilactici FZU106 significantly regulated the mRNA levels of liver genes (including CD36, CYP7A1, SREBP-1c, BSEP, LDLr and HMGCR) involved in lipid metabolism and bile acid homeostasis. Therefore, these findings support the possibility that P. acidilactici FZU106 has the potential to reduce the disturbance of lipid metabolism by regulating intestinal microflora and liver gene expression profiles.

The volatile profiles and microbiota structures of the wheat Qus used as traditional fermentation starters of Chinese rice wine from Shaoxing region

Wheat Qu is used as a fermentation starter in Chinese rice wine brewing and plays important roles on the quality and flavor of the product. The aim of this study was to thoroughly investigate and compare ten traditional wheat Qus collected from different Chinese rice wine manufacturers in Shaoxing region in terms of their hydrolytic enzyme activities, volatile profiles and microbiota structures. Significant variation in the enzymatic activities (glucoamylase, amylase and protease) and volatile components were observed among the samples. Single molecule real-time DNA sequencing technology (SMRT) and culture dependent approach were combined for the first time to investigate the microbial communities in traditional wheat Qus. SMRT indicated that 4 bacterial genera, including Saccharopolyspora, Staphylococcus, Bacillus and Pantoea, and 5 fungal genera, including Aspergillus, Wickerhamomyces, Candida, Alternaria and Fusarium, dominated the wheat Qus and were detected in all ten samples. On the other hand, Staphylococcus gallinarum and Lichtheimia ramose were found to be the most abundant bacterial and fungal species by culture dependent method. Moreover, the potential correlations between microorganisms and volatiles of wheat Qus were also explored using partial least squares regression. Finally, this study provided detailed insight into the microbial communities and volatile profiles presented in wheat Qu.

Development of a novel cooking wine with high-efficiency deodorizing capability via a rapid fermentation strategy

Chinese rice wine, when used as a cooking wine, has the important function of erasing fish and meat odours by evaporating odourous compounds and complementing the flavour of food. The objectives of the current study were to develop a short-term brewing process of rice wine and to evaluate the efficiency of deodorizing fish by preparing novel rice wine for cooking wine products. The technology of unilateral fermentation was applied in the rice wine brewing process, assisted by the pretreatment of enzymatic hydrolysis on rice. Following the optimization of enzymatic hydrolysis with ɑ-amylase, neutral protease, and glucoamylase, fermentation was conducted with Saccharomyces cerevisiae N85 and Lactobacillus plantarum B14. As a result, the primary fermentation period of rice wine was shortened from 15 days to 6 days. Furthermore, the preparation of cooking wine with sage, oregano, ginger, grape seed, and Chinese pepper was optimized through single-factor and response surface tests. The auxiliary material amount, extraction temperature, and extraction time were determined to be 1.61%, 35.8 °C, and 6 days, respectively. Finally, the cooking wine products exhibited 80.2%–88.9% deodorizing capability on 4 kinds of fish, which was more than 60% higher than that of common commercial cooking wines.

Regional characteristics and discrimination of the fermentation starter Hong Qu in traditional rice wine brewing

SummaryHong Qu (HQ) is a fermentation starter used to brew Hong Qu rice wine (HQ wine). The regional characteristics and discrimination of HQ are not fully understood. This study elucidates fermentation characteristics of HQ through sensory evaluation and the analysis of six physicochemical characteristics of HQ wine brewed by twenty‐nine HQ from different regions. Results showed that the complex physicochemical indices of HQ wine would be reduced to three principal components – total acidity, total sugars and non‐sugar solids by principal component analysis. Twenty‐nine HQ samples were classified into four clusters by hierarchical cluster analysis – Cluster A, B, C and D. Cluster B only included Gutian HQ (GTQ) brewing base liquors with a fresh and soft taste, the highest sensory scores and low coefficient of variation (CV). The rest three Clusters mainly included Wuyi HQ (WYQ) brewing base liquors with full‐bodied and tasteful flavours, high CV values and different sensory scores. WYQ could brew more good and less below standard liquors, while the quality of HQ wine brewed using GTQ was more even than that of WYQ. Conclusively, the geographical location and processing technology of HQ are the main external factors contributing to the regional characteristics of HQ wine.

Effect of enzymes addition on the fermentation of Chinese rice wine using defined fungal starter

A higher fermentation capability and quality of a rice wine was achieved, using mixed fungal (Rhizopus chinonsis R01, Asperigillus niger A20, Mucor pusillus M05 and Saccharomyces cerevisiae S10) starter fermentation of japonica rice supplemented with α-amylase (AM), glucoamylase (GAM) and acid protease (AP). Results showed that alcohol content, free amino acids (FAA) and volatile flavor substances concentrations were increased by 49.22%, 85.54%, and 25.71% compared with the control group respectively. To understand the role of enzymes during rice wine brewing, the effects of hydrolases on chemical and physical properties of cooking rice, on the yeast growth, enzyme productivity of molds were determined. Rice starch was hydrolyzed effectively by AM and GAM, the viscosity reduced significantly, the enzyme contact area expanded, which accelerated the further hydrolysis of japonica rice. Increase of hydrolysate promoted the fungi growth, while improved the ability of molds to produce enzymes. AP promoted the protease activity of M. pusillus M05 and A. niger A20, improved protein utilization, increased the content of FAA and formed higher level of flavor substances in rice wine. The results indicate that hydrolase addition can change the physic-chemical state of the mash to enhance microbial biotransformation and modify flavor metabolism.

Development of a Size-Exclusion/Ion-Exclusion/Reversed-Phase Separation Method for the Simultaneous Determination of Inorganic and Organic Acids, Sugars, and Ethanol During Multiple Parallel Fermentation of Rice Wine

An effective method for monitoring the progress of rice wine fermentation (saccharification, glycolysis system, ethanol fermentation, and the TCA cycle) is required owing to the decreasing human resources in rice wine brewing and dramatically increasing export quantity of rice wine. This study aimed to develop an anion-exclusion/size-exclusion/reversed-phase chromatographic (AEC/SEC/RPC) separation protocol for the simultaneous determination of sugars, ethanol, inorganic, and organic acids for the effective monitoring of rice wine fermentation processes. Optimal chromatographic resolutions were obtained by the combination of a polymer-based size-exclusion column and H+-form weakly acidic cation-exchange resin column with a 20.0 mM phthalic acid eluent. The optimized AEC/SEC/RPC separation system determined 16 different species during rice wine fermentation in a single analysis. The developed AEC/SEC/RPC method demonstrated the below useful advantages for (1) evaluating the progress of rice wine fermentation; (2) evaluating the activity of brewing yeast from the behaviors of glucose, phosphate, and ethanol concentration; and (3) obtaining good correlation between the developed and official methods for monitoring glucose and ethanol. Consequently, several beneficial information was obtained for the process control of rice wine brewing by the developed method.