Physicochemical properties of Korean rice wine (Makgeolli) fermented using yeasts isolated from Korean traditional nuruk,a starter culture

The applicability of Saccharomycopsis fibuligera CJN1020, Pichia jadinii CJN1287, and Saccharomyces cerevisiae CJN1514 isolated from Korean nuruk, a starter culture, for preparation makgeolli was investigated. These yeasts were suitable for preparation of both white rice makgeolli using a steam method and white rice-brown rice-wheat flour (WBW) makgeolli using a complex method. Upon physicochemical evaluation, there were no differences in the final ethanol concentrations between white rice makgeolli and WBW makgeolli. Differences in final ethanol yields occurred according to yeast species. Final ethanol yields using S. fibuligera and P. jadinii were 16 and 18% using S. cerevisiae. WBW makgeolli samples received higher sensory scores than white rice makgeolli for overall preference. GC/MS analysis revealed higher amounts of aromatic compounds in WBW makgeolli than in white rice makgeolli. The complex method was suitable for preparation of makgeolli using brown rice and wheat flour.     

Secretome of Aspergillus oryzae in Shaoxing rice wine koji

Shaoxing rice wine is the most famous and representative Chinese rice wine. Aspergillus oryzae SU16 is used in the manufacture of koji, the Shaoxing rice wine starter culture. In the current study, a comprehensive analysis of the secretome profile of A. oryzae SU16 in Shaoxing rice wine koji was performed for the first time. The proteomic analysis for the identification of the secretory proteins was done using two-dimensional electrophoresis combined with matrix-assisted laser desorption/ionization-tandem time of flight mass spectrometry based on the annotated A. oryzae genome sequence. A total of 41 unique proteins were identified from the secretome. These proteins included 17 extracellular proteins following the classical secretory pathway, and 10 extracellular proteins putatively secreted by the non-classical secretory pathway. The present secretome profile greatly differed from previous reports on A. oryzae growing in other solid-state nutrient sources. Several new secretory or putative secretory proteins were also found. These proteomic data will significantly aid the advancement of research on the secretome of A. oryzae, especially in solid-state cultures, and in elucidating the production process mechanism of Shaoxing rice wine koji. The findings may promote the technological development and innovation of the Shaoxing rice wine industry.     

Effect of Ganoderma lucidum on the quality and functionality of Korean traditional rice wine, yakju

The goal of this study was to develop a high value Korean traditional rice wine possessing the pharmaceutical functionality of Ganoderma lucidum. The effects of the fruiting body of G. lucidum on the alcohol fermentation of Korean traditional rice wine, yakju, were investigated. Optimal fermentation conditions for the preparation of G. lucidum-yakju consisted of the koji added at 15% and a fermentation period of 15 d at 25 degrees C. The effects of the amount of G. lucidum added on the acceptability and functionality of G. lucidum-yakju were investigated. G. lucidum GL-1 yakju brewed by adding 0.1% G. lucidum into the mash showed the best acceptability and its angiotensin I-converting enzyme (ACE) inhibitory activity and SOD-like activity were 63% and 42%, respectively, both of which are higher than those of yakju. The high ACE inhibitory activity of G. lucidum GL-1 yakju was found to result from ganoderic acid K in G. lucidum on the basis of physical and spectral data. However, the fibrinolytic activity and antioxidant activity of G. lucidum GL-1 yakju were very low, while tyrosinase inhibitory activity was not determined. From these results, G. lucidum GL-1 yakju may become a new functional Korean traditional rice wine with antihypertensive properties.     

米曲霉(Aspergillus oryzae FAFU)淀粉酶的分离纯化及其酶学性质研究

从米曲霉(Aspergillus oryzae FAFU)发酵产物中提取淀粉酶,通过硫酸铵盐析、透析、DEAE-Sepharose离子交换层析和Sephacryl S-200凝胶柱层析等纯化步骤,回收活性组分,结合十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)进行纯度鉴定,共分离纯化出3种酶:酶Ⅰ、酶Ⅱ、酶Ⅲ。通过酶解淀粉实验,酶解产物经薄层层析(TLC)分析,鉴定出酶Ⅰ、酶Ⅱ为液化酶,酶Ⅲ为糖化酶,经SDS-PAGE电泳确定分子量大小分别为:48.6、49.7、93.5 k Da。对酶Ⅰ、酶Ⅱ的酶学性质进行初步的探究:酶Ⅰ的最适反应温度为50℃,温度在50℃以下稳定性好,55℃的半衰期是40 min,最适反应p H为6.0,在p H7.2~9.6范围内稳定性好;酶Ⅱ的最适反应温度为50℃,温度在45℃以下稳定性好,50℃的半衰期是30 min,最适反应p H为6.6,在p H8.6~10.0范围内稳定性好。     

两株米曲霉菌种的发酵性能研究

将2株米曲霉扩大培养后用于生产试验,并将其发酵酱油的性能进行对比。结果表明,米曲霉1号酱油的氨基酸态氮、pH值、A530 nm、总氮低于米曲霉2号菌,总酸高于米曲霉2号;米曲霉2号酱油的游离氨基酸总含量为6.05 g/100 mL,是米曲霉1号（4.18 g/100 mL）的1.45倍;米曲霉1号酱油中醇类物质、酸类物质和醚类物质相对含量分别达61.53%、14.16%和1.26%,高于米曲霉2号的57.3%、13.07%和0.46%,而酯类物质（3.73%）、酮类物质（1.83%）和醛类物质（16.33%）低于米曲霉2号的3.96%、1.95%和21.31%;米曲霉1号酱油香气浓郁偏醇香味,米曲霉2号酱油香气浓郁偏酯香;米曲霉2号酱油的加热沉淀达到204 mm2,远高于米曲霉1号酱油的25 mm2。加热后过滤可去除米曲霉2号酱油中的沉淀。     

两种生产用米曲霉的形状及蛋白酶性质研究

研究对比了两株米曲霉的形态特征以及成曲的蛋白酶酶学性质。结果显示,两株米曲霉的形态差异明显:米曲霉1号菌落较大、发芽和产孢子较快,种曲及成曲颜色偏黄,菌丝较短,孢子较多;而米曲霉2号菌落较小,孢子发芽时间及产孢子时间比1号晚,成曲孢子较1号少,但菌丝长且粗壮,种曲颜色偏绿,成曲颜色偏白,米曲霉2号的产酶能力强。蛋白酶性质的研究结果显示,两株米曲霉成曲的蛋白酶性质有差异,1号和2号的最适反应温度分别为45℃和50℃,最适反应pH分别为6.0和9.0。此外,两株米曲霉的成曲蛋白酶的耐盐性相当,随着盐浓度的增大,酶活力均逐渐降低,在20%氯化钠条件下,酶活力均降至无盐条件下的20%~30%。     

传统法酿造糯米酒中酵母菌的筛选及发酵特性研究

从云南传统糯米酒中分离得到16株酵母菌,通过产气性能、TTC平板显色、产酯实验的初筛方法,筛选出4株酵母菌进行复筛,再通过耐温实验、耐酒精实验、耐酸实验、发酵力实验,最终筛选出酵母菌Y1和Y2。Y1和Y2菌是理想的米酒酵母菌种,且酵母菌Y2产酯能力较强,用在米酒生产中可增加酯香味。     

Anti-complementary activity of enzyme-treated traditional Korean rice wine (Makgeolli) hydrolysates

BACKGROUND: Makgeolli brewed from rice contains about 150 g kg^?1 alcohol and has a fragrance as well as an acidic and sweet taste. During the brewing process, by‐products such as rice bran and brewery cake are produced. At the end of fermentation the matured mash is transferred to a filter cloth and the Makgeolli is squeezed out from the cake, leaving the lees of the mash. These by‐products have continued to increase every year, resulting in an ecological problem. It is therefore important to develop new uses for them. The objective of this study was to use the by‐products from the brewing of Makgeolli as a valuable functional food or nutraceutical. RESULTS: The anti‐complementary activities of crude polysaccharides isolated from Cytolase hydrolysates of Makgeolli lees at concentrations of 1000 and 500 µg mL^?1 were 84.15 and 78.70% respectively. The activity of polysaccharide krestin (PSK) was 60.00% at 1000 µg mL^?1. The active polysaccharide obtained with Cytolase comprised mainly glucose and mannose (molar ratio 1.00:0.62). CONCLUSION: Glucose‐ and mannose‐rich crude polysaccharides were isolated from the Cytolase hydrolysate of Makgeolli lees. The polysaccharides retain anti‐complementary activity to enhance the immune system as a functional food or nutraceutical. Copyright © 2011 Society of Chemical Industry     

传统米酒酒曲的评价及根霉的分类鉴定

本研究分别采用孝感地区不同种类的酒曲制作米酒,从糖度、酸度、酒精度等方面对米酒质量进行评价,筛选出制备米酒质量最好的酒曲样品,并从中分离得到13株根霉,结合形态学和18SrDNA部分基因序列分析的分子生物学方法对根霉进行了鉴定。结果显示,采集到的5种酒曲中,由孝感麻糖米酒有限责任公司提供的酒曲质量最好;从中分离的13株根霉中6株为米根霉(Rhizopus o-ryzae),7株为华根霉(Rhizopus chinesis)。以上结果表明,酒曲质量是影响米酒质量的关键因素;传统鉴定方法和现代分子生物学鉴定方法相结合使得菌种鉴定准确度高,结果可靠。     

Effects of cross-linked resistant rice starch on the quality of Korean traditional rice cake

Jeolpyeon, the Korean traditional rice cake, was prepared from the newly developed dry rice flour with 10 and 20% cross-linked resistant starch (RS4) to improve sanitation during processing and to enrich the functional properties of dietary fiber. The rice flour was prepared from white rice ‘Chuchungbyeo’ through soaking, drying and milling using a pin mill with a built-in 120 mesh sieve. The total dietary fiber contents were 44.97% for RS4, 3.57% for rice cake, 7.78 and 11.35% for 10 and 20% RS4 added jeolpyeon, respectively. With an increase in RS4 content, the swelling power, solubility, water binding capacity, and all pasting viscosities decreased, while lightness increased. Cohesiveness and resilience in the 10% RS4 added jeolpyeon was higher than those in the control. The preference test showed that the color and overall quality increased with the addition of RS4 and overall quality was the highest in the 10% RS4 added jeolpyeon.     

蜂蜜接合酵母协同传统曲种发酵广东黄酒的工艺研究

以糯米为原料,采用传统曲种及蜂蜜接合酵母LGL-1发酵广东黄酒。在酵母添加量、酵母添加时间、水添加量和前发酵时间4个单因素的基础上,以乙醇体积分数为响应值,采用响应面法对广东黄酒的发酵工艺参数进行优化。结果表明,酿造黄酒的最佳工艺条件为酵母添加量4 m L(100 g干米中)、酵母添加时间50 h、水添加量78%(质量分数)、前发酵时间8. 4 d。该条件下得到的黄酒含糖质量浓度为95. 6 g/L,乙醇体积分数为11. 7%vol,酒体色泽鲜红,外观清澈透亮,具有典型的黄酒醇香。蜂蜜接合酵母LGL-1可应用于低糖型黄酒的酿造。     

Exposure assessment and risk characterisation of ethyl carbamate from Korean traditional fermented rice wine,Takju and Yakju

Ethyl carbamate is one of the most hazardous chemicals naturally occurring in food, and is present in alcoholic beverages. Korean traditional rice wine, Takju and Yakju, is frequently consumed in Korea, but there have been no studies characterising the risks of ethyl carbamate in these products. In order to assess and characterise the exposure risk of ethyl carbamate in Korean traditional rice wines, ethyl carbamate was investigated by means of GC-MS. The analytical methods were optimised and validated through determining linearity, detection limit, quantification limit, recovery and precision. A total of 283 traditional Korean rice wines, including 175 Takju and 108 Yakju samples, were analysed. Exposure assessment was performed by factoring in ethyl carbamate content, daily consumption and body weight. Daily exposures of ethyl carbamate were estimated for adults in four age groups, and risks of ethyl carbamate were characterised by the margin of exposure, which is more than 10 000. Based on this study, the risks of ethyl carbamate in Korean traditional rice wine were shown to be of low concern.     

Optimization for rice koji preparation using aspergillus oryzae CJCM-4 isolated from a korean traditional meju

To obtain a useful mold strain in rice-doenjang production, enzyme activities were investigated in rice and wheat koji prepared with 13 different strains isolated from traditional Korean meju. The CJCM-4 strain, which had been selected as a superior strain for the production of protease, was identified as Aspergillus oryzae by the gene sequence of the ITS-5.8S rDNA region as well as aflatoxin production capacity. The enzyme activities of koji prepared with CJCM-4 according to the polishing degree of rice bran were examined. The enzyme activities of koji prepared with 70% milling degree of rice bran were higher than those of other kojis. Protease activity showed its highest level on day 3 at 30°C. Glucoamylase activity showed its highest level on day 2 at 30°C. The optimum enzyme production of koji was determined at different conditions such as incubation time, temperature, moisture, and inorganic salt content. The optimum ratio of water added to the rice for the production of enzymes was 35% on the dry basis of the rice, and the optimum temperature was 25°C. When inorganic salts were added to increase enzyme activity, the combined addition of 0.15% CaCO₃ and 0.05% NaH₂PO₄ resulted in the highest enzyme activities.     

米曲霉GX0011β-果糖基转移酶的性质研究

β-果糖基转移酶是酶法由蔗糖生产低聚果糖所必需的酶,本文对从米曲霉GX0011分离纯化得到的β-果糖基转移酶性质进行了研究。结果表明,该酶催化蔗糖转化成蔗果三糖的Km和Vmax分别为0.319mol/L和0.713mol/min/L,最适pH和最适温度分别为5.0～6.0和45℃。葡萄糖是该酶的竞争性抑制剂,其抑制常数Ki=0.608mol/L。经苯甲磺酸氟(PMSF)、N-溴代二酰亚胺(NBS)、1-乙基-3-(3-二甲氨基丙基)碳二亚胺盐酸盐(EDC)和间硝基苯磺酸钠(TNBS)对酶进行化学修饰及底物保护实验,推测该酶活性中心可能包括丝氨酸/苏氨酸、色氨酸、天冬氨酸(谷氨酸)残基,而赖氨酸残基可能与维系酶活性中心构象有关,但不是酶活性必需基团。实验还表明,超声波能在一定程度上提高酶活力,在300W功率下作用5min可提高酶活12%左右。低浓度乙醇对酶活影响并不十分显著,乙醇浓度达20%时,酶活仅损失19%。     

变质传统发酵陈化黄酒微生物的分离和鉴定

坛装传统发酵黄酒在灌装灭菌后的陈化储存过程中会产生浑浊、酸变等变质现象,使得黄酒的酸度升高,香味丧失而无法饮用.其具体原因尚未明确.比较了变质陈化黄酒与未变质陈化黄酒在主要理化指标上的差异;而后采用改良MRS、醋酸菌、酵母菌和霉菌培养基分离筛选到一些菌种,观察了其菌落形态和细胞特征,初步鉴定出5株乳酸杆菌、4株酵母和4株霉菌.     

变质传统发酵陈化黄酒微生物的分离和鉴定

坛装传统发酵黄酒在灌装灭菌后的陈化储存过程中会产生浑浊、酸变等变质现象,使得黄酒的酸度升高,香味丧失而无法饮用。其具体原因尚未明确。比较了变质陈化黄酒与未变质陈化黄酒在主要理化指标上的差异;而后采用改良MRS、醋酸菌、酵母菌和霉菌培养基分离筛选到一些菌种,观察了其菌落形态和细胞特征,初步鉴定出5株乳酸杆菌、4株酵母和4株霉菌。     

传统阳江豆豉发酵过程中米曲霉的筛选及发酵条件优化

对从广东阳江豆豉的曲醅中筛选的米曲霉菌株进行培养基和发酵条件优化,结果表明,该菌产酶最适培养基的组成为添加3%的酵母粉、1%的葡萄糖、3%的硝酸钠和0.50%的氯化钙于基础PDA培养基中。该菌株产酶最优发酵条件为温度30℃,pH值为7~8,250 mL三角瓶中装瓶量为120 mL。在此最优条件下进行生长曲线绘制,培养12 h时,开始出现白色菌落,到36 h时,白色菌丝体明显增多,蛋白酶活力也持续增大,菌株培养48 h时,黄绿色孢子开始产生,蛋白酶活力达到最大值,到60 h时,菌株增长明显减慢,产生大量孢子,颜色较深,蛋白酶活力开始下降。综合菌量和蛋白酶活力,培养48 h为最适发酵时间。     

米曲霉发酵提取甘薯中去氢表雄酮工艺优化

以甘薯生全粉为原料,采用米曲酶发酵提取去氢表雄酮（dehydroepiandrosterone,DHEA）,基于提取物中DHEA定性分析基础上,探讨米曲酶孢子悬浮液接种量、发酵时间、发酵温度和液固比等因素对米曲霉发酵提取甘薯中DHEA得率的影响,结合单因素与响应面试验优化得最优发酵工艺：米曲酶孢子悬浮液接种量6%,发酵时间72 h,发酵温度 30 ℃,液固比 15∶1（mL/g）,此条件下 DHEA 得率可达 94.70 μg/100 g,显著（p＜0.05）高于预发酵-酸解法、酶解法提取DHEA得率。