Chinese Yellow Rice Wine Research Articles

Impact of Bacillus subtilis on Chinese yellow rice wine (Huangjiu) fermentation: Method variations and flavor analysis

This investigation explores the impact of various fermentation techniques and the inoculation of Bacillus subtilis spores on the physicochemical properties and principal flavor profiles of Huangjiu. Employing sensory analysis, headspace solid-phase microextraction, gas chromatography-tandem mass spectrometry (HS-SPME-GC–MS), and orthogonal partial least squares discriminant analysis (OPLS-DA), we observed that these variables significantly alter the physicochemical attributes of Huangjiu. Our analysis, integrating volatile organic compounds (VOCs) with odor activity values (OAV), revealed that while B. subtilis inoculation modifies the concentrations of key flavor compounds, it does not affect their types. Notably, the inoculation enhances the concentrations of 13 primary flavor compounds, thereby enriching floral and fruity notes while reducing higher alcohol levels. These findings contribute valuable insights into the flavor formation mechanisms of Huangjiu and guide the optimization of fermentation processes.

Conjugated molecularly imprinted polymers based on covalent organic frameworks: Fluorescent sensing platform for specific capture of urea and elimination of ethyl carbamate

This study described the preparation of an azide covalent organic framework-embedded molecularly imprinted polymers (COFs(azide)@MIPs) platform for urea adsorption and indirect ethyl carbamate (EC) removal from Chinese yellow rice wine (Huangjiu). By modifying the pore surface of COFs using the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction, COFs(azide) with a high fluorescence quantum yield and particular recognition ability were inventively produced. In order to selectively trap urea, the COFs(azide) were encased in an imprinted shell layer via imprinting technology. With a detection limit (LOD) of 0.016 μg L-1 (R2 = 0.9874), the COFs(azides)@MIPs demonstrated a good linear relationship with urea in the linear range of 0–5 μg L-1. Using real Huangjiu samples, the spiking recovery trials showed the viability of this sensing platform with recoveries ranging from 88.44 % to 109.26 % and an RSD of less than 3.40 %. The Huangjiu processing model system achieved 38.93 % EC reduction by COFs(azides)@MIPs. This research will open up new avenues for the treatment of health problems associated with fermented alcoholic beverages, particularly Huangjiu, while also capturing and removing hazards coming from food.

Quality properties of Chinese Sichuan-style sausages as affected by Chinese red wine, yellow rice wine and beer

ABSTRACT The objective of this research was to investigate quality properties of Chinese Sichuan-style (CSS) sausages treated with Chinese red wine (RW), yellow rice wine (YR) and Chinese beer (CB). The CSS sausages treated with 13% Chinese liquor as the control, and other three groups treated with 6.5% Chinese red wine as the RW group, 6.5% Chinese yellow rice wine as the YR group, and 6.5% Chinese beer as the CB group on the basis of 6.5% Chinese liquor addition were prepared. Results showed that RW, YR and CB group CSS sausages displayed higher L ⁎(39.46–43.44) and A w, lower pH (5.78–5.91) and protein content (33.75–37.44%) compared with those of the control. The YR group sausages had higher b ⁎ value (23.25), total area% of aldehydes (3.09%) as well as flavor score (6.72), while the CB group CSS sausages showed higher a* value (24.29), total area% of aldehydes (3.94%) and kenones (2.13%), as well as lower free thiol groups (10.88 nmol/mg protein) relative to those of the control group. No significant difference in overall quality scores were detected between YR and CB group CSS sausages. The PCA showed that RW group CSS sausages achieved similar effects as CB group for volatile, color and sensory properties, which could separate CB/YR group CSS sausages from those of the other two groups. The results of this study indicated that it was applicable to improve quality properties of CSS sausages by using 6.5% Chinese yellow rice wine or beer on the basis of adding 6.5% Chinese liquor during processing.

TiO2@SiO2 flexible nanofiber membrane-based syringe membrane solid phase extraction for determination of beryllium in Chinese yellow rice wine samples by graphite furnace atomic absorption spectrometry

TiO2@SiO2 flexible nanofiber membrane-based syringe membrane solid phase extraction for determination of beryllium in Chinese yellow rice wine samples by graphite furnace atomic absorption spectrometry

Analysis on driving factors of microbial community succession in Jiuyao of Shaoxing Huangjiu (Chinese yellow rice wine)

The microbial ecosystem of fermented food is greatly disturbed by human activities.Jiuyao is important saccharification starter for brewing huangjiu. The interaction between environmental factors and microorganisms significantly affected the microbial community structure at different stages of Jiuyao manufacturing. This study combined environmental factor analysis and high-throughput sequencing technology to comprehensively analyze the specific changes of microbial community and environmental factors in each fermentation stage of Jiuyao production and their correlation. The results showed that the activities of liquefaction enzyme, glycosylation enzyme and acid protease reached the highest value on the 8 th day (192 h) after the beginning of fermentation, and the cellulase activity reached the highest value at the end of fermentation. Pediococcus（37.5 %-58.2 %）, Weissella（9.2 %-27.0 %） and Pelomonas（0.1 %-12.1 %） were the main microbial genera in the genus bacteria, and Saccharomycopsis（37.1 %-52.0 %）, Rhizopus（12.5 %-31.0 %） and Saccharomyces（4.0 %-20.5 %） were the main microbial genera in the genus fungi. The results of correlation analysis showed that the microbial communities in Jiuyao were closely related to environmental factors. Most microbial communities were positively correlated with temperature, but negatively correlated with ambient humidity, CO2 concentration, acidity and water content of Jiuyao. In addition, the transcription levels of enzymes related to microbial glucose metabolism in Jiuyao were higher in the late stage of Jiuyao fermentation. Interestingly, these enzymes had high transcription levels in fungi such as Saccharomycopsis, Rhizopus and Saccharomyces, as well as in bacteria such as Pediococcus and Lactobacillus. This study provides a reference for revealing the succession rule of microbial community structure caused by environmental factors during the preparation of Jiuyao in Shaoxing Huangjiu.

Speciation of Fe(II) and Fe(III) in Chinese Yellow Rice Wine Using Direct Immersion Dual-Drop Microextraction Coupled with Graphite Furnace Atomic Absorption Spectrometry (GFAAS)

A new direct immersion dual-drop microextraction (DIDDME) procedure is described for Fe(III) and Fe(II) speciation followed by detection with graphite furnace atomic absorption spectrometry. This method is based upon the selective reaction of 1-(2-pyridylazo)-2-naphthol (PAN) and N-benzoyl-N-phenylhydroxylamine (BPHA) with Fe(II) and Fe(III) to form complexes at pH 1.5. Two solvent drops that contain PAN and BPHA were concurrently immersed in a sample solution for simultaneous separation of Fe(III) and Fe(II), respectively. This method eliminated time-consuming and labor-intensive oxidation of Fe(II) or reduction of Fe(III), which may provide incomplete conversion and contamination. Using the optimal conditions, the detection limits were 0.067 ng mL−1 and 0.054 ng mL−1 for Fe(II) and Fe(III) with relative standard deviations of 6.0% and 5.1%, respectively. Enrichment factors of 300-fold were obtained. The procedure was successfully utilized for the determination of Fe(II) and Fe(III) in Chinese yellow wine. To evaluate accuracy of this method, a rice certified reference material was analyzed and the result was in good agreement with the certified value.

Purification and identification of antioxidant and angiotensin converting enzyme-inhibitory peptides from Guangdong glutinous rice wine

Guangdong glutinous rice wine, a type of Chinese yellow rice wine, is rich in a variety of bioactive peptides. In this study, polypeptides with antioxidant and angiotensin converting enzyme (ACE)-inhibitory activities were isolated from Guangdong glutinous rice wine, and their activities and molecular mechanisms were studied. The peptide fraction (F2-2), which exhibited the strongest antioxidant and ACE inhibitory activities, was separated by ultrafiltration and RP-HPLC. A total of 76 peptides were identified by LC-MS/MS, and four peptides with potential antioxidant activities were obtained: VLSGA (445.2536 Da), VISGA (445.2536 Da), MGKAA (476.2417 Da) and GHVAA (453.2336 Da). These four peptides showed significant antioxidant activity with EC50 values of 0.118 mg/mL, 0.056 mg/mL, 0.054 mg/mL and 0.027 mg/mL respectively, and effectively protected cells against oxidative damage. Molecular docking showed that all these four peptides could interact with key active sites on the receptor proteins CD38 and Keap1. Furthermore, these peptides showed good safety and stability according to in silico prediction.

Quantitative study on core bacteria producing flavor substances in Huangjiu (Chinese yellow rice wine)

In the process of Huangjiu fermentation, microbial succession plays an important role in quality control of Huangjiu. In this study, Lactobacillus acetotolerans was screened as internal standards, and the bacterial communities in Huangjiu fermentation were quantified definitively by high-throughput amplandin-qPCR. Based on the absolute quantitative results, multivariate statistics combined with flavor substance content analysis showed that Lactobacillus was significantly correlated with 11 core flavor substances. Macrotranscriptomics was further used to examine the transcription levels of genes related to flavor substances. The results showed that Lactobacillus was involved in the biosynthesis of several core flavor substances such as ethyl acetate during fermentation, and the correlation was strongest at the post-fermentation stage (day 5–23). It was confirmed that Lactobacillus was the core species in the formation of flavor substance in Huangjiu. This study provided valuable reference for further revealing the mechanism of microbial interaction during Huangjiu fermentation and improving the quality of Huangjiu.

Application of mixed-culture with Lactobacillus brevis and Saccharomyces cerevisiae to Chinese yellow rice wine brewing for ethyl carbamate regulation

Co-culturing two or more species has recently been used in fermenting foods for product flavor or safety control. Ethyl carbamate (EC) is a potential carcinogenic compound presented in Chinese yellow rice wine which can be reduced by fermentation starters modification. In this work, the effect of Lactobacillus brevis (L. brevis) on EC in yellow rice wine fermentation with Saccharomyces cerevisiae (S. cerevisiae) was studied and an optimal mixed-culture fermentation method was constructed according to comparative analyses of EC concentration and fundamental quality. EC concentration could be further reduced by 68.4% at most through adding 108 cfu/L L. brevis during S. cerevisiae fermentation. L. brevis also had beneficial influence on hedonic quality of yellow rice wine. Meanwhile, the effect of gallic acid on EC formation in this mixed-culture fermentation system was elucidated. Unfortunately, the coexistence of gallic acid and L. brevis attenuated their inhibitory effect on EC formation.

Chinese Yellow Rice Wine Processing with Reduced Ethyl Carbamate Formation by Deleting Transcriptional Regulator Dal80p in Saccharomyces cerevisiae.

Ethyl carbamate (EC) is a potential carcinogen that forms spontaneously during Chinese rice wine fermentation. The primary precursor for EC formation is urea, which originates from both external sources and arginine degradation. Urea degradation is suppressed by nitrogen catabolite repression (NCR) in Saccharomyces cerevisiae. The regulation of NCR is mediated by two positive regulators (Gln3p, Gat1p/Nil1p) and two negative regulators (Dal80p/Uga43p, Deh1p/Nil2p/GZF3p). DAL80 revealed higher transcriptional level when yeast cells were cultivated under nitrogen-limited conditions. In this study, when DAL80-deleted yeast cells were compared to wild-type BY4741 cells, less urea was accumulated, and genes involved in urea utilization were up-regulated. Furthermore, Chinese rice wine fermentation was conducted using dal80Δ cells; the concentrations of urea and EC were both reduced when compared to the BY4741 and traditional fermentation starter. The findings of this work indicated Dal80p is involved in EC formation possibly through regulating urea metabolism and may be used as the potential target for EC reduction.

Application of bamboo leaves extract to Chinese yellow rice wine brewing for ethyl carbamate regulation and its mitigation mechanism

Bamboo leaves extract (BLE) contains various effective ingredients, including phenolic compounds. In this study, the effect of BLE on ethyl carbamate (EC) formation was investigated in Chinese yellow rice wine brewing with three different fermentation starters (Saccharomyces cerevisiae, Saccharomyces cerevisiae and Lactobacillus brevis, and Chinese yeast). As a result, BLE showed significant inhibition effect on EC in multi-microbial fermented rice wine, by preventing the reactions between urea/citrulline and ethanol. We found that BLE had influence on arginine transport (GAP1, CAN1, ALP1, and VBA2 gene) in Saccharomyces cerevisiae (S. cerevisiae), which significantly up-regulated arginine uptake gene expression in vacuole (VBA2 gene) so that inhibited arginine metabolism. Besides, the presence of BLE could improve the overall quality of Chinese yellow rice wine. Consequently, it was worthwhile applying BLE to Chinese rice wine fermentation, especially the wine brewing with S. cerevisiae and Lactobacillus brevis starter.

Effect of gallic and protocatechuic acids on the metabolism of ethyl carbamate in Chinese yellow rice wine brewing

It was studied that gallic and protocatechuic acids played important roles in ethyl carbamate (EC) forming. Gallic and protocatechuic acids can reduce the arginine consumption through inhibiting the arginine deiminase enzyme. Therefore, they are generally added to regulate EC catabolism in the course of yellow rice wine leavening at the third day. In this work, gallic and protocatechuic acids made little influence on the growth of Saccharomyces cerevisiae. Besides, the addition of 200mg/L gallic or protocatechuic acid could prevent the transformation from urea/citrulline to EC. Gallic acid showed better inhibiting effect that the content of EC could be reduced by 91.9% at most. Furthermore, the production of amino acids and volatile flavor compounds are not markedly affected by phenolic compounds. The discoveries reveal that EC can be reduced by supplying gallic acid or protocatechuic acid while yellow rice wine leavening.

Determination of Ethyl Carbamate (EC) by GC-MS and Characterization of Aroma Compounds by HS-SPME-GC-MS During Wine Frying Status in Hakka Yellow Rice Wine

Wine frying status is one of the most important processes in the brewing of Chinese yellow rice wine (CYW) and has a great influence on the quality and flavor of CYW. The present work determined the ethyl carbamate (EC) concentration by gas chromatography-mass spectrometry (GC-MS) and aroma compounds by headspace solid-phase microextraction GC-MS (HS-SPME-GC-MS) during wine frying status in CYW. In addition, effects of wine frying conditions on the changes of EC and aroma compounds were also investigated. Results indicated that EC concentration increased along with the increase of wine frying temperature and time. Pearson test indicated that EC had highly significant correlation (p < 0.01) with temperature and time. Esters, alcohols, and ethers consisted of the most aroma components and constituted the main flavor of CYW. Considering EC concentration, main flavor, unique ingredients, and proportions of volatile aroma compounds, 70 °C and 11–20 min are the most appropriate temperature and time for wine frying of CYW. It is necessary to control wine frying conditions influencing EC formation and aroma compounds in CYW brewing.

Bacterial Diversity Analysis during the Fermentation Processing of Traditional Chinese Yellow Rice Wine Revealed by 16S rDNA 454 Pyrosequencing.

Rice wine is a traditional Chinese fermented alcohol drink. Spontaneous fermentation with the use of the Chinese starter and wheat Qu lead to the growth of various microorganisms during the complete brewing process. It's of great importance to fully understand the composition of bacteria diversity in rice wine in order to improve the quality and solve safety problems. In this study, a more comprehensive bacterial description was shown with the use of bacteria diversity analysis, which enabled us to have a better understanding. Rarefaction, rank abundance, alpha Diversity, beta diversity and principal coordinates analysis simplified their complex bacteria components and provide us theoretical foundation for further investigation. It has been found bacteria diversity is more abundant at mid-term and later stage of brewing process. Bacteria community analysis reveals there is a potential safety hazard existing in the fermentation, since most of the sequence reads are assigned to Enterobacter (7900 at most) and Pantoea (7336 at most), followed by Staphylococcus (2796 at most) and Pseudomonas (1681 at most). Lactic acid bacteria are rare throughout the fermentation process which is not in accordance with other reports. This work may offer us an opportunity to investigate micro ecological fermentation system in food industry.

Determination of Ethyl Carbamate in Chinese Yellow Rice Wine by Diatomaceous Earth Extraction and GC/MS Method.

A sensitive and rapid analytical method based on alkaline diatomaceous earth extraction followed by GC/MS was developed for the quantitative determination of the toxic contaminant ethyl carbamate (EC) in yellow rice wines. The optimal extraction conditions were investigated. With the application of diatomaceous earth extraction, the damage of organic acids to the capillary column was greatly reduced. By using d5-EC as an internal standard for quantitative analysis of EC, the linearity of the calibration curves was good between 10 and 1000 ng/mL. The LOD and LOQ were 1.7 and 5.0 μg/kg, respectively. The spiked level of EC was 5.0-300 μg/kg, and the average recovery of the spikes was between 78.4 and 98.2%, with an RSD between 4.3 and 8.3%. Upon validation by five laboratories when spiked with 50, 100, and 300 μg/kg, the average respective recoveries were 102.9, 102.2, and 98.7% with a RSD between 0.7 and 8.1%. The validation results demonstrated that the method is fast, simple, selective, and suitable for the determination of EC in yellow rice wines.

Ethyl carbamate formation regulated by Saccharomyces cerevisiae ZJU in the processing of Chinese yellow rice wine

SummaryEthyl carbamate (EC) is a probable carcinogen existing in most fermented foods. Throughout traditional fermentation processes, the Chinese fermentation starter plays an important role, but it contains varieties of microorganisms which make inhibiting EC efficiently become a challenge. Therefore, the traditional fermentation starter is substituted with a single yeast strain (Saccharomyces cerevisiae ZJU) to regulate EC catabolism. In this work, S. cerevisiae ZJU can reduce EC formation and the data of EC concentration show that there is 85.6% reduction of EC at most using S. cerevisiae ZJU instead of the traditional fermentation starter. Extracellular urea and citrulline were the leading precursors of EC. The content of amino acids and volatile flavour compounds in the experimental group has no significant influence compared to the natural fermentation. The findings in this work suggest that EC can be regulated by means of the fermentation starters variation.

Simultaneous determination of ethyl carbamate, chloropropanols and acrylamide in fermented products, flavoring and related foods by gas chromatography–triple quadrupole mass spectrometry

A simultaneous determination method was established by gas chromatography–triple quadrupole mass spectrometry (GC–MS/MS) for ethyl carbamate, acrylamide and chloropropanols (1,3-dichloropropane-2-ol (1,3-DCP), 2,3-dichloropropane-1-ol (2,3-DCP), 3-monochloropropane-1,2-diol (3-MCPD) and 2-monochloropropane-1,3-diol (2-MCPD)) in fermented products, flavoring and related foods. Ethyl carbamate-d5, 1,3-DCP-d5, 3-MCPD-d5 and acrylamide-d3 were used as isotope internal standards for ethyl carbamate, DCPs, MCPDs and acrylamide, respectively. The sample was extracted and cleaned in one single step by a combined clean-up column packed with Extrelut™ NT and primary secondary amine (PSA). The concentrated extract was directly injected without derivatization, separated by an Innowax (cross-bonded polyethylene glycol) capillary column and measured by GC–MS/MS. The calculated limits of detection (LODs) in the sample matrix were 1.8, 1.0, 2.1, 5.3, 5.1 and 5.0 μg kg−1 for ethyl carbamate, 1,3-DCP, 2,3-DCP, acrylamide, 3-MCPD and 2-MCPD, respectively. The average recoveries in different matrices at three spiked concentration levels (20, 100 and 400 μg kg−1) were 88.6–112, 92.6–103, 92.1–106, 86.2–107, 90.4–109 and 91.0–105% with relative standard deviations (RSDs) (Average RSDs in bracket) of 4.4–10.2 (6.4%), 3.7–7.3 (5.4%), 3.9–7.7 (5.2%), 4.4–9.3 (6.4%), 4.1–10.7 (6.3%) and 3.7–7.9% (5.6%), respectively. Two to six contaminants were simultaneously found in some of the soy sauce samples. Ethyl carbamate, acrylamide, 3-MCPD and 2-MCPD were found in the instant noodle flavoring. Trace levels (<12 μg kg−1) of ethyl carbamate, acrylamide or 3-MCPD were detected in tomato sauce and salad dressing. Both ethyl carbamate and acrylamide were found in some of the curry products and Chinese yellow rice wine. Only ethyl carbamate was found in beer and grape wine.

Acetate ester production by Chinese yellow rice wine yeast overexpressing the alcohol acetyltransferase-encoding gene ATF2.

Acetate ester, which are produced by fermenting yeast cells in an enzyme-catalyzed intracellular reaction, are responsible for the fruity character of fermented alcoholic beverages such as Chinese yellow rice wine. Alcohol acetyltransferase (AATase) is currently believed to be the key enzyme responsible for the production of acetate ester. In order to determine the precise role of the ATF2 gene in acetate ester production, an ATF2 gene encoding a type of AATase was overexpressed and the ability of the mutant to form acetate esters (including ethyl acetate, isoamyl acetate, and isobutyl acetate) was investigated. The results showed that after 5 days of fermentation, the concentrations of ethyl acetate, isoamyl acetate, and isobutyl acetate in yellow rice wines fermented with EY2 (pUC-PIA2K) increased to 137.79 mg/L (an approximate 4.9-fold increase relative to the parent cell RY1), 26.68 mg/L, and 7.60 mg/L, respectively. This study confirms that the ATF2 gene plays an important role in the production of acetate ester production during Chinese yellow rice wine fermentation, thereby offering prospects for the development of yellow rice wine yeast starter strains with optimized ester-producing capabilities.

SIMULTANEOUS DETECTION OF ETHYL CARBAMATE AND UREA IN CHINESE YELLOW RICE WINE BY HPLC-FLD

Ethyl carbamate (EC) is a naturally occurring component in fermented products, especially in Chinese yellow rice wine. A rapid and simple HPLC method is proposed for the simultaneous analysis of EC and urea in Chinese yellow rice wine. EC and urea reacted with xanthydrol (9H-xanthen-9-ol) under hydrochloric acid solution to produce fluorescent substances that could be quantified using FLD (λex = 234 nm, λem = 600 nm) after chromatographic separation from interferences. The determination results proved that such a method had good linear relationship (the correlation coefficient, R2 > 0.999), good repeatability (RSD < 3.4%), and good recovery (94.4%–101%). The limits of detection (LOD) and limits of quantitation (LOQ) were 7.00 µg/L and 20.7 µg/L, respectively, for EC; whereas, 100 µg/L and 300 µg/L, respectively, for urea. The new HPLC-FLD procedure is suitable for the fast, reliable, convenient, and inexpensive determination of EC and urea in Chinese yellow rice wine.

Ethyl carbamate formation regulated by ornithine transcarbamylase and urea metabolism in the processing of Chinese yellow rice wine

SummaryEthyl carbamate (EC) is a potential carcinogenic compound present in most of the fermented foods. In this work, EC was inhibited through different strategies during vinification of Chinese yellow rice wine. EC can be inhibited by the use of ornithine in contrast to the control at peak point. However, the utilisation of urease resulted in little inhibitive effect on EC. The comparative data of intracellular ornithine transcarbamylase (OTCase) and arginine deiminase (ADI) among four experiments showed that EC was positively regulated by intracellular OTCase, but ADI was not determined. Extracellular urea and citrulline content was significantly increased by adding ornithine (P &lt; 0.05), whereas ethanol played a minor role in EC formation. The correlation analysis between EC and OTCase or urea revealed a linear association (correlation coefficients above 0.8). These findings suggested that OTCase may be a required factor regulating EC formation during the brewing of Chinese yellow rice wine.