Traditional Rice Wine Research Articles

Development of a flavor-oriented synthetic microbial community for pour-over rice wine: A comprehensive microbial community analysis

Huangjiu, a traditional Chinese alcoholic beverage, varies widely in quality and consistency when brewed using the traditional pour-over rice wine technique, largely due to the variability in its microbial community in an open fermentation environment. This study streamlined the microbial complexity using amplicon sequencing and culture-dependent methods, leading to the identification of a set of core microbial species instrumental in flavor development. A synthetic microbial community was crafted from these key species and employed in fermentation experiments. In this study, we demonstrated that the synthetic microbial community not only replicated the major flavor profiles of traditional pour-over rice wine but also it is further proved that the core species directly determines the main flavor of pour-over rice wine, these findings are supported by our quantitative analysis of volatile compounds and sensory evaluation data. This research underscores the potential of synthetic microbial communities in standardizing production processes and improving the sensory quality of traditional beverages like Huangjiu.

Enhancing energy recovery from expired rice wine via microbial electrolysis of supernatant and anaerobic digestion of concentrate after gravity settling

Makgeolli is a traditional Korean rice wine with a short shelf life, making the management of expired makgeolli (EM) challenging. Meanwhile, its organic- and nutrient-rich nature renders EM a promising bioconversion substrate. To explore the potential to enhance energy recovery and profitability from EM, the concentrate (MC) and supernatant (MS) separated from EM by gravity settling were utilized for hydrogen production in microbial electrolysis cells (MECs) and methane production through anaerobic digestion (AD), respectively. MS demonstrated superior electron and hydrogen recovery compared to EM in MECs, with greater enrichment of exoelectrogenic Geobacter. In the AD tests, MC exhibited faster and more stable methane production with higher yield than EM. This separate processing of MS and MC was predicted to produce 18–21% more energy (2,210 MJ/m3 EM) and 6–180% higher revenue (101 USD/m3 EM) than processing whole EM using either MEC or AD alone, warranting further research for optimization.

Structural characterization, antioxidant and immunomodulatory activities of a polysaccharide from a traditional Chinese rice wine, Guangdong Hakka Huangjiu

Hakka Huangjiu, a traditional Chinese rice wine, boasts a rich history and is known for its immunomodulatory, antibacterial, anti-aging and anti-fatigue effects. However, there is limited research on the primary active components and molecular mechanism of the bioactivity of Hakka Huangjiu. To address this gap, this study assessed the structural characteristics, antioxidant, and immunomodulatory activities of the polysaccharide-1 of Guangdong Hakka Huangjiu (HP1). Structural analysis revealed that HP1 had a low molecular weight polysaccharide of 5550 Da, primarily consisting of glucose (93.2 %), with smaller amounts of xylose, mannuronic acid and galactose. Methylation and NMR analysis suggested that the main glycosidic linkages present in HP1 are α-D-Glcp-(1→, →4)-α-D-Glcp-(1 → and →6) -α-D-Glcp-(1→. Furthermore, HP1 exhibited dose-dependent DPPH·, ABTS+ and OH· scavenging activity. HP1 exhibited significant protection of HepG2 cells from H2O2 damage. Additionally, HP1 induced the release of NO, TNF-α, IL-6 and iNOS in RAW264.7 cells. HP1 treatment significantly increased mRNA expression of TNF-α, IL-6, iNOS, COX-2, IL-1β and TGF-β1. These results suggested that polysaccharides HP1 may have potential as a novel natural antioxidant and immunomodulatory product for use in nutraceuticals and functional foods.

Fermentation dynamics, physicochemical and sensory characteristics of Malaysian traditional rice wines

PurposeMalaysian rice wines (tapai) manufactured in small-scale industries are usually formulated based on personal experiences under minimally controlled conditions for generations, especially in Sabah, one of the East Malaysian states. However, the quality and safety of rice wines were receiving increased attention to ensure better quality control, particularly those produced on an industrial scale. Therefore, this research aims to determine the fermentation dynamics and consumers’ acceptance of Malaysian rice wines produced using different sasad (a local term for starter culture from Sabah).Design/methodology/approachThe physicochemical [total soluble solids (TSS), alcohol content, total titratable acidity (TTA) and pH] and microbiological [total yeast and mould count (TYMC) and total lactic acid bacteria (LAB) count] changes in Malaysian rice wines were determined to better understand the fermentation process for future process optimisation. Additionally, sensory evaluations were conducted to determine the consumers’ preferences for the rice wines.FindingsThe overall fermentation dynamics of rice wines exhibited similar trends with slight variations between the samples, demonstrating the effect of microbial compositions of sasad on the quality of final rice wines. Additionally, consumer acceptance tests showed that rice wines with darker shades of yellow and a stronger alcoholic aroma were preferable.Originality/valueThis is the first research that provides important insights into both the fermentation dynamics and consumers’ acceptance of Malaysian traditional rice wines, enriching the rice wine literature from the academic perspective and contributing to the production of safe and high-quality rice wines.

Functional insights into microbial communities of Korean traditional rice wine (makgeolli) during fermentation

Makgeolli, a traditional Korean rice wine, produced by fermenting glutinous rice using a nuruk containing various microbes that can facilitate saccharification and alcoholic fermentation. The microbial communities in makgeolli determine its quality by metabolizing raw materials into physiologically active substances, such as volatile acids, ethanol, and amino acids. However, the microbial metabolic pathways associated with physicochemical properties remain poorly understood. Therefore, this study applied shotgun metagenomic sequencing to investigate the microbial communities of two makgeolli types, produced using Jinju gokja and Sansung nuruk as starters, during fermentation. Microbial structures differed depending on the starter type (nuruk), with Firmicutes and Proteobacteria dominating in the Jinju and Sansung makgeolli, respectively. Initially, the sugar content increased, displaying high level of alpha-glucosidase coding gene. Thereafter, the microbial genes encoding lactate dehydrogenase and alcohol dehydrogenase increased on day 3 of fermentation. Furthermore, lactic acid bacteria, such as Pediococcus acidilactici and Leuconostoc lactis, increased on day 3 of fermentation and were negatively correlated with pH. However, Leuconostoc sp. showed a positive correlation with acetic acid, an indicator of abnormal fermentation. These findings reveal interaction between makgeolli quality and different microbial strains related with various metabolic functions, providing insights for enhancing quality and optimizing fermentation conditions.

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.

Dynamics and correlation between volatile compounds and microbial community in chestnut rice wine fermentation

SummaryChestnut rice wine, also called banli mijiu (BLMJ), uses Chinese chestnut (Castanea mollissima Blume) in the fermentation of traditional glutinous rice wine. This study characterised the microbial communities and volatile compounds in BLMJ and explored their correlations. Headspace solid‐phase microextraction‐gas chromatography–mass spectrometry (HS‐SPME‐GC–MS) revealed that the major volatile compounds during BLMJ fermentation include eighteen important volatile compounds (OAV > 1). High‐throughput sequencing (HTS) demonstrated that the abundance and diversity of bacteria were significantly greater than those of fungi during the fermentation process. Among them, Kropensteria and Saccharomyces were the most abundant bacteria and fungi at the genus level during the fermentation of BLMJ. Spearman's correlation analysis revealed that eighteen important volatile compounds were significantly positively correlated with seven microbial genera (|r| > 0.9, P < 0.01), including six bacterial genera (Rhodococcus, Lactococcus, Pseudomonas, Janthinobacterium, Unclassified_f_Bacillaceae and Burkholderia‐Caballeronia‐Paraburkholderia) and one fungal genus (Saccharomyces). Therefore, these bacterias and fungi may be core functional microorganisms during BLMJ fermentation. The findings may provide important reference for mediating the microbial community during fermentation to improve the flavour of BLMJ.

The Common and Unique Microbiota in Sabah’s Traditional Rice Wine Starter Cultures (SASAD)

Rice wine is an alcoholic beverage produced through the fermentation of cereal grains, mainly rice, with microbial starters consisting of fungi and bacteria. However, the microbes in the rice wine starter cultures have never been documented comprehensively except for a few studies that looked into culturable microbes. Hence, their exact core microbiota contents especially those unculturable microbes remained unknown. Therefore, this research aimed to identify the fungal and bacterial communities in sasad through ribosomal amplicon-based next-generation sequencing and analysis that captured both the culturable and unculturable microbiota. The results showed that two fungal phyla (Mucoromycota and Ascomycota) with five genera (Mucor, Rhizopus, Saccharomycopsis, Wickerhamomyces, and Kodamaea) and two bacterial phyla (Proteobacteria and Firmicutes) with 10 genera (Kosakonia, Weissella, Enterobacter, Lactococcus, Pseudomonas, Bacillus, Chromobacterium, Paludibacterium, Enterococcus, and Gluconobacter) were identified as the core microbiota (relative abundance > 1.00%) in the sasad samples. Some of these microbes have been reported in other starter cultures, but some are unique to the sasad (Chromobacterium and Paludibacterium). Hence, this research provides the first comprehensive report on the microbes in sasad and provides important insights into the potential roles of core microbiota. These data may be used to facilitate the development of starter cultures with defined microbial compositions for the consistent production of safe and high-quality rice wines in the future.

Fungal communities and their correlation with the sensory quality of rice wine from the Xiaogan and Dazhou regions in China

In this study, we performed a comparative analysis of fungal communities and cultivable yeast isolates in rice wine from the Xiaogan and Dazhou regions using Illumina MiSeq high-throughput sequencing technology and traditional culture-dependent methods. And we further explored the correlation between the sensory quality and fungal communities in rice wine. The results demonstrated no significant difference (P > 0.05) in the abundance and diversity of fungal communities and cultivable yeast isolates between Xiaogan and Dazhou rice wine. The dominant fungal genera were Rhizopus and Saccharomyces, with Saccharomyces cerevisiae accounting for the greatest proportion of yeast isolates. The rice wine samples could be divided into two types based on the composition of fungal communities. Type 1 mainly contained Rhizopus and Saccharomyces, while type 2 mainly contained Rhizopus. Properties such as lightness, blueness-yellowness, methane levels, ethanol levels, organic sulfide content, and soluble solids content accounted for the main differences between the two types of rice wine. In addition, Candida and Clavispora showed a significant positive correlation (P < 0.05) with the aromatic substances in rice wine. The findings of the study enrich our understanding of traditional rice wine, providing meaningful information for the improvement and development of the traditional rice wine industry.

Ion-exchange purification, nano-HPLC–MS/MS identification and molecular dynamics simulation of novel umami peptides from fermented grain wine (Huangjiu)

Huangjiu is a traditional Chinese fermented rice wine with abundant peptides, but the umami peptides are little known due to the wine’s complex matrix. Herein, the target umami fraction was enriched with sensory-guided separation coupled with ultrafiltration, ion-exchange, and gel chromatography purification. A total of 1901 peptides were identified from gel F1 fraction with nano-HPLC–MS/MS. Eight novel umami peptides DWDPHGL, VPEPEPH, LTPEPEH, GANQLDPR, FREE, LDFR, QEGW, and RDH were filtered by virtual screening and sensory evaluation. They exhibited thermal stability at 373.15 K and the taste thresholds in water were between 0.29 and 0.65 mmol/L. Among them, RDH was crucial, due to a relatively high dose over threshold (DoT) factor (1.12). Molecular docking results showed that residues ASP147, SER148, ARG151, TYR220, SER276, and ALA302 contributed most to the interaction of peptide and T1R1. Moreover, molecular dynamics simulation and weak interaction analysis suggested the important role of intramolecular forces in peptide thermal stability.

Evaluating the quality of soy residue‐supplemented Korean traditional rice wine and its lactic acid bacteria

AbstractBackground and ObjectivesTraditional Korean rice wine (makgeolli), contains various microorganisms, including lactic acid bacteria (LAB). This study investigated the utilization of biji, a by‐product of soy processing, as a substitute for rice in makgeolli fermentation. We evaluated the functional properties of biji‐makgeolli and examined the probiotic properties of LAB isolated from it.FindingsBiji‐makgeolli exhibited lower sugar and alcohol contents and higher pH and acidity than 100% rice makgeolli (control). Moreover, biji‐makgeolli displayed higher total viable cells (5.54–6.32 log CFU/g), yeast (4.23–6.59 log CFU/g), and LAB (5.44–6.48 log CFU/g) than control (5.26, 2.59, and 5.23 log CFU/g), which increased with biji addition. Furthermore, biji‐makgeolli showed higher total phenolic content, antioxidant capacity, and α‐glucosidase inhibitory activity, increasing with biji addition. Three LAB strains were isolated from makgeolli, identified as Pediococcus pentosaceus)‐KX886792 in control (CW) and P. pentosaceus‐KX886790 (RW), and Lactobacillus coryniformis (RM) in 50% biji replaced makgeolli. All groups (CW, RW, and RM) survived exposure to pH 3 for 3 h and 0.3% bile salts for 24 h and exhibited the ability to adhere to HT‐29 cells. RW (20.7%) and RM (27.5%) showed antioxidant effects, having higher ABTS+ values than CW (7.5%). The expression of tumor necrosis factor‐α and interleukin‐8 was significantly suppressed in RW and RM compared with that in CW. RW and RM showed antimicrobial activity against Escherichia coli. Additionally, RM was active against Staphylococcus aureus and exhibited a cholesterol‐lowering effect.ConclusionsBiji enhances the antioxidant capacity of makgeolli, and LAB isolated from biji‐makgeolli exhibit potential probiotic properties.Significance and NoveltyBiji is a potential additive for producing plant‐derived LAB in makgeolli and developing functional foods.

Effects of simultaneous and sequential mixed fermentation of non‐Saccharomyces strains and a Saccharomyces cerevisiae strain on the fermentation process and volatile compounds of Mijiu

SummaryThe combined use of non‐Saccharomyces yeasts and Saccharomyces cerevisiae in mixed fermentation is considering as a potential way to improve the flavour characteristics of Mijiu (a traditional rice wine in China). In this study, we investigated the effects of mixed fermentation, including simultaneous and sequential inoculation fermentation, of typical non‐Saccharomyces yeast strains (Saccharomycopsis fibuligera; Candida glabrata) and an S. cerevisiae strain on the fermentation process and volatile compounds of Mijiu. The results showed that the fermentation rate of Mijiu was improved by the simultaneous inoculation fermentation of different non‐Saccharomyces yeasts and S. cerevisiae. However, the increase of volatile compounds in the simultaneous inoculation fermentation depended on non‐Saccharomyces yeast species, although the positive contribution of non‐Saccharomyces yeasts to volatile compounds of Mijiu was confirmed in their pure fermentation. The sequential inoculation fermentation significantly enhanced the content or complexity of volatile compounds of Mijiu but with low‐fermentation rate. This could be attributed to the change of the number of non‐Saccharomyces yeast cells during the mixed fermentation possibly caused by the inhibition of S. cerevisiae with high concentration on non‐Saccharomyces yeasts. Our work provided useful information on the mixed inoculation fermentation strategy combining suitable non‐Saccharomyces yeasts and S. cerevisiae for improving the fermentation rate and the aroma quality of Mijiu.

Comparing the differences of physicochemical properties and volatiles in semi-dry Hakka rice wine and traditional sweet rice wine via HPLC, GC–MS and E-tongue analysis

This study aimed to explore effects of indica rice addition, rice soaking time and rice soup addition on total sugar and alcohol content of semi-dry Hakka rice wine (HRW) and compare its difference in physicochemical properties and volatiles with traditional sweet rice wine (TSRW) via HPLC, GC–MS and E-tongue. The optimal fermentation conditions of semi-dry HRW were 50 % indica rice addition, 12 h rice soaking time and 85 % rice soup addition. The total sugar (16.13 mg/mL) of semi-dry HRW was significantly lower than that of TSRW (135.79 mg/mL), especially the trehalose, glucose, sucrose and maltose. Its alcohol content was significantly higher than that of TSRW. There were significant differences in volatile components between semi-dry HRW and TSRW, especially esters, alcohols and ketones, but no significant differences in organic acids and amino acids. Results obtained could provide reference data for improving the fermentation process and quality of semi-dry HRW.

Selection and Characteristics of Mashing Methods for Quality Improvement of Traditional Raw Rice Wine (Takju)

Selection and Characteristics of Mashing Methods for Quality Improvement of Traditional Raw Rice Wine (Takju)

The dynamics of physicochemical properties, microbial community, and flavor metabolites during the fermentation of semi-dry Hakka rice wine and traditional sweet rice wine.

The dynamics of physicochemical properties, microbial community and flavor metabolites during fermentation of two typical Hakka rice wine were investigated. Results showed that total sugar content was 136.83g/L in sweet rice wine, which almost 8 times higher than that in semi-dry rice wine. Its amino acid contents especially bitterness amino acids were also higher than those in semi-dry rice wine. Most organic acids in Hakka rice wine had the tendency of increase in initial stage of fermentation, following a decrease and finally being almost stable. A total of 131 volatiles including esters, alcohols, aldehydes, acids, ketones were detected. Pediococcus, Bacillus, Acinetobacter, Pantoea, Enterobacter and Lactobacillus were the dominant bacterial genera and Monascus, Saccharomyces, Rhizopus were the dominant fungal genera, which are strongly associated with the significant changes in flavor metabolites during Hakka rice wine fermentation. The obtained findings provided reference data for the optimization of Hakka rice wine fermentation.

Impact of solid‐state fermentation by Aspergillus niger 4Q and Cyberlindnera fabianii J2 on antioxidant and flavor properties of whole grain barley

AbstractBackground and ObjectivesAspergillus niger 4Q and Cyberlindnera fabianii J2 were isolated from a traditional Chinese sweet rice wine starter because of their better fermentation characteristics and sensory properties of final products. To understand the impacts of the cofermentation with Aspergillus niger 4Q and Cyberlindnera fabianii J2 in a solid state on the nutritional and physico‐chemical properties of whole grain barley, yellow barley and black barley were used as raw materials. Content of chemical and nutritional compositions, in vitro antioxidant activity, color, and volatile flavor compound analysis of untreated, cooked and fermented barley samples were evaluated.FindingsThe contents of total phenolic compounds, total flavonoids, and anthocyanin of black barley were 1.25 times, 1.21 times, and 2.05 times higher than those in yellow barley (p &lt; .05). After fermentation, the proteins, water‐soluble dietary fiber, and β‐glucan contents of both black barley and yellow barley samples were about respectively 1.3 times, 4.6 times, and 1.2 times higher than those in raw materials (p &lt; .05). Total proportion of phenolic compounds and flavonoids, along with the antioxidant capacity, free radical scavenging rate and Fe2+ chelating activity were significantly increased (p &lt; .05). Lighter and brighter color were observed in fermented barleys which might be credit to the reduced anthocyanins. The acidic methyl esters, uniquely existed in untreated barley, were transformed into acetate esters after fermentation. Ethyl 3‐methyl‐acetate, with a fruity aroma, was the major proportion of esters in fermented barley, endued the unique flavor to fermented barley.ConclusionsSolid‐state fermentation of yellow barley and black barley by A. niger 4Q and C. fabianii J2 could effectively improve their nutritional and physico‐chemical properties.Significance and NoveltyThis study may contribute to providing a solution for improving the nutritional and sensory preterits of whole grain barley, as well as a theoretical support for promoting the direct utilization of barley in food processing.

Combination of four bacterial strains isolated from Yamahai-shubo in traditional Japanese sake brewing.

This study investigated the interactions of four bacteria strains isolated from Yamahai-shubo, the source of yeast used to produce a Japanese traditional rice wine, Yamahai-shikomi sake. The bacterial strains were nitrate-reducing Pseudomonas sp. 61-02, Leuconostoc mesenteroides LM-1, Lactiplantibacillus plantarum LP-2, and Latilactobacillus sakei LS-4. We examined fermentation factors for Yamahai-shubo and Yamahai-shikomi sake samples to compare the suitability of their bacterial combination (16 variations). As a result of principal component analysis, we found that two major groups were formed; one containing strain LP-2 and the other containing strain LS-4, and that strains LP-2 and LS-4 were important in the Yamahai-shikomi sake in the presence of strains 61-02 and LM-1. Then, we investigated the effects of strains LP-2 and LS-4 on the concentration of organic acids (pyruvic acid, citric acid, succinic acid, malic acid, and lactic acid) in Yamahai-shikomi sake. Only in lactic acid, a tendency to decrease with a smaller proportion of LS-4 strains in Yamahai-shubo was observed. Subsequently, their effect on the concentration of diacetyl, crucial for aroma, was investigated between the LP-2 and LS-4 strains. The sample prepared in the absence of strain LS-4 exhibited the lowest concentration of diacetyl. This result was supported by the statistical analysis for the sensory scores performed for aroma of each Yamahai-shikomi sake sample. In conclusion, strain LP-2 plays a more significant role in improving Yamahai-shikomi sake quality with strains LM-1 and 61-02 rather than strain LS-4 in Yamahai-shubo preparation and Yamahai-shikomi sake brewing.

The volatile flavor and the antioxidant properties of a novel chrysanthemum rice wine during natural aging.

Chrysanthemum morifolium cv. Fubaiju, a traditional tea in southern China with high nutritional and health functions was used in this study. Optimized production conditions of a novel chrysanthemum rice wine (FRW) were obtained by the Box-Behnken design response surface experiment. FRW with best sensory quality was developed with 0.68% chrysanthemum, 0.79% Jiuqu and 0.81:1 liquid-to-solid ratio. Compared with rice wine (RW) control, the total phenolic and flavonoid contents, as well as antioxidant activity of the FRW increased significantly. GC-MS analysis showed that more flavor compounds including alcohols, aldehydes, acids, and esters were detected in FRW. During the aging process, it was found that the antioxidant substances, the antioxidant activity and the flavor substances decreased, with the wine body tending to be homogenized. After 6months of storage, overall sensory quality of FRW was more harmonious, with special nectar taste, which dramatically improved the flavor characteristics and functionality compared with traditional RW.

Innovation in sweet rice wine with high antioxidant activity: Eucommia ulmoides leaf sweet rice wine.

The dried leaves of Eucommia ulmoides Oliv., which have a high nutritional value, are mainly used in both medicine and food. In this study, we used Eucommia ulmoides leaf superfine powder as an additive in the fermentation of glutinous rice (Semen Oryzae Glutinosae) to develop a new healthcare product, Eucommia leaf sweet rice wine. The fermentation conditions were optimized, and the nutrient value was evaluated through analyses of metabolites, functional compositions, antioxidant capacity, and antihyperglycemic, antihyperlipidemic, and antihypertensive abilities. The metabolic analysis demonstrated that Eucommia leaf sweet rice wine contained a large number of flavonoids and other metabolites. Eucommia leaf sweet rice wine had higher contents of flavonoid (729.0 ± 0.11 μg/g), free amino acids (55.0 ± 0.37 μg/g), polyphenol (150.0 ± 0.43 μg/g), and polysaccharide (0.25 ± 0.03 μg/g) than traditional sweet rice wine, with increases of 14.7, 2.6, 6.8, and 6.3 times, respectively. In addition, an analysis of antioxidant capacity in vitro revealed that Eucommia leaf sweet rice wine had a high level of activity in scavenging 2, 2-diphenyl-1-picrylhydrazyl (DPPH), superoxide anion, and hydroxyl radicals, as well as in reducing iron, indicating that it was a strong antioxidant. Furthermore, Eucommia leaf sweet rice wine had a high cholate binding capacity and could significantly inhibit α-amylase, α-glucosidase, and angiotensin-converting enzyme (ACE) activity. In conclusion, this study developed a new application of Eucommia leaf in sweet rice wine fermentation and brewed Eucommia leaf sweet rice wine with strong antioxidant activity and positive antihypertensive, antihyperglycemic, and antihyperlipidemic effects in vitro. This study suggests new opportunities for the wider use of Eucommia ulmoides leaves and adds variety to sweet rice wine.

Characterisation of Korean rice wine (makgeolli) prepared by different processing methods

Four methods of preparing makgeolli, a traditional Korean turbid rice wine, were reported in this study. The four processing routes include single-stage simultaneous saccharification and fermentation of glutinous rice with nuruk – a Korean starter culture (1SF-N), single-stage fermentation with nuruk and yeast (1SF-YN), two-stage fermentation (2SF) and three-stage fermentation (3SF). Chemical analysis was used to determine how the different processing routes could affect the rice wine's properties in terms of alcohol content, pH, colour, mineral content, proximate composition, antioxidant activity, total phenolic content, sugar, free amino acid, and organic acid profile. Sensory analysis using polarised projective mapping (PPM) and 62 participants found that sweetness is the most desirable attribute for makgeolli among New Zealand consumers with sourness and bitterness as less desirable. The 2SF makgeolli sample had the highest concentration of glucose (8.2 mg/mL) and maltose (107 mg/mL) and in the PPM experiment was the most preferred out of the four processing methods. The 1SF-N makgeolli sample had the highest alcohol (13% ABV), crude protein (4.9%), antioxidant activity, total phenolic (621 mg GAE/L) and free amino acids content, however, it was the least overall liked makgeolli sample. Overall, the novelty of this research includes formulating a traditional Korean turbid rice wine in a Western country environment and evaluating consumer perception of makgeolli beyond the normal clientele in South Korea. From these results it is suggested that the properties of makgeolli can be manipulated via processing to suit the brewer's sensory needs that best fits the consumer market.