蓝莓果酒的工艺优化及其抗氧化活性研究

以蓝莓为试材,通过对5种酵母(Saccharomyces)(RV002、RW、SY、BV818、RV171)的发酵特性确定酿造酒的最佳酵母,采用正交试验同时对酵母接种量、初始糖度、偏重亚硫酸钾添加量和p H值等发酵工艺参数进行了优化。采用DPPH法、FRAP法分析了蓝莓果酒的抗氧化活性。结果表明:蓝莓果酒最适酵母菌为RW,酵母接种量为0. 8%,偏重亚硫酸钾添加量为40 mg/L,初始糖度为24%,p H值为4. 0。随着发酵时间的延长,蓝莓果酒的DPPH自由基清除率以及FRAP值逐渐减小,最终达到平稳状态,说明抗氧化能力下降。     

芒果果酒发酵工艺优化及其挥发性风味物质分析

采用桂七品种的芒果原浆为原料,以酒精度和残糖量为指标,利用单因素试验与正交试验考察各因素(酵母的添加量、SO2的添加量、白砂糖添加量、发酵时间)对芒果果酒发酵工艺的影响,同时利用顶空固相微萃取结合GC-MS技术分析芒果果酒中挥发性风味物质种类及相对含量。结果表明:各因素对芒果果酒酒精度的影响次序为:SO2的添加量白砂糖添加量酵母的添加量发酵时间,其最佳芒果果酒发酵条件为:酵母添加量0.015%,发酵时间5 d,糖添加量为6 g,SO2添加量为105 mg/L,在此条件下芒果果酒的酒精度为12.6%,残糖量为6.89%;同时,通过分析其挥发性风味物质发现芒果果酒中共检测出32种化合物,相对含量较高的为醇类和脂类,共占总挥发性成分的94.61%,发酵过程对酒体产生了影响,醇类和脂类对芒果果酒的香味起着积极的作用。     

山葡萄酒的研制及发酵优化研究

采用广东茂名山葡萄为原料,经分选、洗涤、去梗、破碎、发酵等工艺研制而成的山葡萄发酵酒。采用正交实验方法,通过测量糖度、酸度和酒精含量变化分析菌种在不同发酵起始糖度、接种酵母量、发酵液pH值、发酵时间、发酵温度等不同发酵条件所产生的发酵效果以及对山葡萄酒发酵品质的影响。结果表明,接种酵母8%,发酵前糖度为11%,发酵pH值为3.2,发酵时间9d,发酵温度22℃,可获得较好的发酵效果。发酵酒清亮透明,酒度17%,无杂质、酒体有光泽,色泽自然、悦目,口味浓郁醇厚,酸甜适口。     

马尾藻提取液在菠萝果酒酿造中的应用

以马尾藻提取液和菠萝汁的混合液进行发酵生产果酒,实验结果表明,马尾藻提取液菠萝果酒发酵的最佳工艺条件为:发酵初始表观糖度为22%,pH值为4.0,发酵温度为20℃,马尾藻提取液与菠萝汁混合比例为1:1(体积比).     

响应面法优化玉米生料生产乙醇工艺的研究

以全玉米粉为原料,对生料发酵乙醇的工艺进行研究,通过单因素实验以及响应面优化实验探讨原料粒度、底物浓度、生料酶添加量以及糖化酶添加量等因素对发酵的影响。结果表明,全玉米粉生料发酵乙醇的最佳工艺条件为50目全玉米粉为原料,底物浓度为37%,生料酶1.25%(w/w),加入酵母活化液(干酵母加量0.05%),并添加氮源尿素以及青霉素,恒温32℃发酵85 h,酒份能够达到19.86%(v/v),淀粉利用率为90.25%,响应面分析R-sq80%,R-sq(调整)80%,表示所建立的模型对异变有足够的解释能力。     

橘子菠萝复合果酒发酵工艺研究

以橘子为主料、菠萝为辅料,采用安琪活性干酵母和果酒酵母作为发酵剂,酿制橘子菠萝复合果酒。以酒精度、残糖量和感官评分为评价指标,通过单因素实验和正交试验设计,确定橘子菠萝复合果酒的最佳制作工艺。以酒精度为评价指标确定的最佳工艺为:接种量0. 4 g/L,加糖量20%,pH值4. 0;以感官评价为指标确定的最佳工艺为:接种量0. 2 g/L,加糖量25%,p H值3. 5,所酿制的橘子菠萝复合果酒酒香浓郁,口味柔和,色泽亮黄,具有菠萝特有的果香。     

樱桃啤酒香气成分分析

采用溶剂萃取法提取樱桃啤酒酒中的香气成分,经气相色谱-质谱(GC-MS)联机分析,发酵完成后放置7天的样品(Y1)鉴定出48个香气组分,发酵完成后放置30天的样品(Y2)鉴定出46个香气组分。结果表明,醇类化合物和酯类化合物为樱桃啤酒样品中最主要的香气成分,并且,不同放置时间的樱桃啤酒香气成分有明显变化,Y1、Y2醇类成分占总成分相对百分含量分别为32.22%和30.39%,Y1、Y2酯类成分占总成分相对百分含量分别为30.05%和34.57%。     

解淀粉芽孢杆菌(Bacillus amyloliquefaciens)FS6摇瓶发酵条件优化

[目的]对解淀粉芽孢杆菌(Bacillus amyloliquefaciens)FS6的摇瓶发酵工艺进行优化。[方法]通过对发酵培养基成分和发酵条件的单因素试验和正交试验,测定生防菌株FS6对人参立枯丝核菌的抑菌效果和菌体生长量,来确定其最适发酵培养基和发酵条件。[结果]最适摇瓶发酵培养基配方为葡萄糖30 g,酵母浸粉40 g,Mg SO_4·7H_2O_2 g,甘油10 m L,K_2HPO_42 g,H_2O 1000 m L;最优培养条件为接种量6%,摇瓶装液量50 m L/250m L,摇床转速160 r/min,初始p H值6.0,培养温度28℃,培养时间12 h。[结论]解淀粉芽孢杆菌FS6在最适摇瓶发酵培养基及发酵条件下,对人参立枯病菌的抑菌活性最好,为该菌株的工业化生产奠定了基础。     

秸杆发酵工艺条件的优化

采用混合菌株对秸杆发酵进行了正交实验,对发酵工艺进行了优化,确定了较佳的发酵工艺条件,即尿素添加量0.5%、麦麸3%、KH2PO4和MgSO4分别为0.1%和0.15%.发酵液初始pH值为8.0,接种量为15%,发酵温度为30℃.     

玉米淀粉制备燃料酒精的工艺优化

研究了发酵法制备燃料酒精的工艺流程,针对传统的工艺中发酵醪液浓度偏低、能耗高、原料利用率低等问题进行了探讨。通过在不同的条件下改变糖化酶加入量、发酵温度、发酵时间、酵母添加量等实验参数,得出发酵制备燃料酒精的最佳工艺条件。结论为:糖化酶加入量为150 u/g,发酵温度为40℃,发酵时间为60 h,酵母添加量为1‰。     

产香酵母菌处理烟叶碎片制备特色烟草浸膏的工艺研究

为利用烟叶碎片制备特色烟草浸膏,采用WY803号产香酵母菌处理烟叶碎片,优化产香工艺制备特色烟草浸膏。采用同时蒸馏萃取法采集烟草浸膏的香气成分,并利用气相色谱-质谱联用进行分析。结果表明,经WY803产香酵母菌处理烟叶碎片后所得到的特色烟草浸膏不仅具有增加烟气浓度、丰富烟香的作用,而且具有提高烟香细腻度和甜润性的作用;并为卷烟香气赋以特殊的醇和的酿甜香味,体现了淡雅香的中式卷烟特点。其优化产香工艺为将烟叶碎片水提物灭菌后,添加10%的高粱粉,接种1%的WY803。在30℃的条件下发酵14天。与未经产香处理的普通烟草浸膏的香味成分比较,该特色烟草浸膏成分中的特征香味成分有:呋喃酮、呋喃醇、苯乙醇、新植二烯、巨豆三烯酮、二羟基紫罗兰酮、2-乙酰基吡咯等。     

Deacidification of clarified passion fruit juice using different configurations of electrodialysis

The deacidification of clarified passion fruit juice (P edulis v flavicarpa) was investigated using the electrodialysis process (ED). Different stack configurations like conventional electrodialysis (ED2C), three compartments electrodialysis (ED3C) and electrodialysis with bipolar membranes (EDBM3C, EDBM2C) were tested. The conventional electrodialysis did not allow the deacidification of the clarified juice, whilst with the other configurations the pH of juice was increased from 2.9 (initial value) to 4.0 (target level). The ED performances were evaluated as a function of the nature of the anion exchange membrane (AEM), flow rate and current density. The physico‐chemical and sensorial properties of the deacidified juices were similar : the titrable acidity was reduced from 4.3 to 1.14% w/w, the dry soluble extract varied from 13.2 to 11% w/w, the anion concentration was significantly decreased (60% of organic and 85% of inorganic anions were eliminated), the cation concentration remained inchanged, except for the sodium concentration that increased by using ED3C and EDBM3C configurations. The aroma of the passion fruit juice was preserved after treatment whatever the ED configuration used. The EDBM2C configuration deserves a special attention because the consumption of chemicals is totally eliminated and a valuable solution of citric acid with 89% of purity can be produced. Copyright © 2003 Society of Chemical Industry     

苹果酒发酵工艺研究

使用新鲜苹果为丰要原科,利用市面普遍销售的安琪酵母酿造苹果酒,选取接种量、初始pH、发酵温度等对影响苹果酒品质的3个关键因子,分别以苹果酒感官评分、酒精度和残糖量等3个质量指标,应用L<,9>(3<'4>)正交试验设计优化了苹果酒发酵工艺条件,得到以下结论:100 g苹果加水50 mL粉碎过滤,加入酵母量为1.5 g,...     

Medium optimization for lipid production through co‐fermentation of glucose and xylose by the oleaginous yeast Lipomyces starkeyi

Co‐fermentation of lignocellulose‐based carbohydrates is a potential solution to improve the economics of microbial lipid production. In the present paper, experiments were performed to optimize the media composition for lipid production by the oleaginous yeast Lipomyces starkeyi AS 2.1560 through co‐fermentation of glucose and xylose (2 : 1 wt/wt). Statistical screening of nine media variables was performed by a Plackett–Burman design. Three factors, namely mixed sugar, yeast extract and FeSO₄, were found as significant components influencing cellular lipid accumulation. Further optimization was carried out using a Box–Behnken factorial design to study the effects of these three variables on lipid production. A mathematical model with the R² value at 96.66% was developed to show the effect of each medium composition and their interactions on the lipid production. The model estimated that a maximal lipid content of 61.0 wt‐% could be obtained when the concentrations of mixed sugar, yeast extract and FeSO₄ were at 73.3 g/L (glucose 48.9 g/L, xylose 24.4 g/L), 7.9 g/L and 4.0 mg/L, respectively. The predicted value was in good accordance with the experimental data of 61.5%. Compared with the initial media, the optimized media gave 1.59‐fold and 2.03‐fold increases for lipid content and lipid productivity, respectively.     

冰糖橙皮渣发酵产燃料乙醇的工艺优化

采用纤维素酶、果胶酶和β-葡萄糖苷酶对冰糖橙皮渣进行水解,所得还原糖液接种异常毕赤酵母进行发酵,考察了酵母接种量、发酵时间、pH和发酵温度等单因素对乙醇得率的影响。单因素结果表明:接种量为12%、发酵时间72 h、pH 4.5、发酵温度33℃时乙醇得率最高。在此基础上设计L9(34)正交实验。结果表明,最佳工艺条件为pH 4.5,接种量12%,发酵时间72 h,发酵温度30℃。在此条件下乙醇产率为0.2451 g/g,显著高于单因素实验(0.2263 g/g)和正交实验结果(0.2329 g/g)。     

Ethanol-Herstellung mit Bakterien

Ethanol production with bacteria . Strains of Saccharomyces cerevisiae have mostly been used for the production of ethanol from sugar by yeasts. Recently it was shown that the bacterium Zymomonas mobilis has some advantages compared to yeast for the production of industrial alcohol. Compared to traditional yeast fermentation, ethanol yield is about 5% higher than with yeast, since less sugar is incorporated into cell material by this bacterium. Like yeast, Zymomonas mobilis has remarkably high ethanol tolerance which enables the bacterium to produce ethanol concentrations of more than 13 vol.-% from sugar solutions of appropriate concentration. Investigations of the spectrum of lipids present have shown that this bacterium contains large quantities of hopanoids which are presumably of significance for the stabilization of cell membranes in the presence of ethanol. Since the cost of the sugar greatly influences the profitability fraction formed in the production of glucose syrup from wheat flour was investigated. It was shown that after enzymatic saccharification of this waste starch the glucose was efficiently fermented to ethanol by Zymomonas mobilis. It is planned to broaden the substrate spectrum of Zymomonas mobilis by gene cloning techniques so that in future pentoses, e. g. xylose or arabinose, can also be fermented to ethanol by this organism.     

Effect of fermentation conditions on yeast growth and volatile composition of wine produced from mango (Mangifera indica L.) fruit juice

In this study mango juice fermentation at laboratory scale with controlled inoculation using selected yeast strain was performed (Saccharomyces cerevisiae 101). Effect of fermentation conditions (temperature, pH, SO₂ and aeration) on wine fermentation was evaluated based on yeast growth, duration, fermentation rate and volatile composition. The composition of the major volatile compounds with low boiling points was determined by gas chromatography under the different operating conditions of fermentation temperature (15-35 °C), pH (3.5-6.0), SO₂ (100-300 ppm) and aeration (initial dissolved O₂ and shaking at 30 rpm). Temperature had important effect on yeast growth and on the levels of volatile compounds. It was observed that the final concentrations of ethyl acetate and some of the higher alcohols decreased when fermentation temperature increased to 25 °C (35 mg/l at 15 °C and 27 mg/l at 25 °C). SO₂ stimulated the yeast growth up to certain level and in excess it inhibited the yeast metabolism. Ethanol concentration slightly increased with the addition of 100 ppm SO₂ (8.2 g/l) and decreased with increase in concentration of SO₂ (6.2 g/l in 300 ppm SO₂). Aeration by shaking increased the viable cell count (from 52 × 10⁶ in the absence of oxygen to 98 × 10⁶ in shaking at 30 rpm) but decreased the ethanol productivity (from 7.2 in initial dissolved O₂ to 6.5 g/l shaking at 30 rpm). With the results obtained it was concluded that the temperature (25 °C), pH (5), SO₂ (100 ppm) and must with initial oxygen were optimum for better quality of wine from mango fruits. The results of the present study considering the traditionally recognized preference for low alcoholic fermentation temperatures in wine making.     

Soy proteins for foods centering around soy sauce and tofu

In the Orient, soy proteins have been used for human consumption for centuries, during which various kinds of unique soy protein foods have been established. Some of these products, such as tofu, have a bland flavor, but there are also those products having a distinctive flavor and an aroma like fermented soy sauce. Both types are acceptable for worldwide populations. In earlier times, the consumption of these soy protein foods in the U.S. was mostly confined to Orientals. Recently, however, the koikuchi type of soy sauce has been consumed widely by non-Orientals through nationwide supermarkets. Annual production in the U.S. has reached more than 16,500 kl. Tofu has also become popular in the U.S. because of its bland flavor which enables it to be used in many dishes. Fermented soy sauce is completely different in the constituents of aroma and flavor from chemical soy sauce. Koikuchi shoyu is a typical Japanese type of fermented soy sauce characterized by a strong, appetizing aroma. The fermentation process consists of koji fermentation byAspergillus species and the subsequent brine fermentation, which contains lactic acid and alcoholic fermentations. Miso is a paste product produced through a similar fermentation. Tofu is a soy milk curd product made through a nonfermented process from soy milk.     

人参发酵液的活性物质分析及其功效研究

为开发人参发酵液在化妆品领域的应用,使用食用级黄酒酵母发酵人参并测定发酵液中多糖、蛋白质和人参皂苷的含量。通过DPPH自由基清除实验和羟自由基清除实验测定其抗氧化能力,并将其作用于成纤维细胞,采用MTT细胞毒性试验评估其对成纤维细胞的增殖作用。用荧光定量PCR检测12种炎症相关的基因在人参发酵液作用的永生化表皮细胞中的表达量,评估人参发酵液的抗炎症效果。结果表明,人参发酵液富含多糖,质量浓度为6.982 g/L,蛋白质和人参皂苷的质量浓度分别为1.039和0.045 g/L。体积分数为10.49%的人参发酵液可清除50%的DPPH自由基,19.62%的人参发酵液可清除50%的羟自由基;体积分数为0.01%的人参发酵液培养的成纤维细胞存活率甚至超过100%,可有效促进细胞增殖;人参发酵液能引发炎症反应,并在短时间内激活并募集白细胞到炎症部位发挥免疫功能。     

填料塔中钠碱溶液脱除烟气中SO_2研究

在内径为400 mm的填料塔内,以Na2SO3为吸收剂进行了烟气脱硫模拟实验研究,重点考察了吸收液pH值、液气比(VL/Vg)、空塔气速、烟气中SO2初始浓度、吸收液温度及吸收剂初始浓度等对脱硫率的影响,确定出各影响因素与脱硫率间的关系及实验室规模下本工艺适宜的操作条件。结果表明,在吸收液pH=6—7、液气比1—2 L/m3、空塔气速1—1.5 m/s、吸收液温度50℃以下、吸收剂Na2SO3初始浓度0.3—0.5 mol/L、进口SO2质量浓度约为4 300 mg/m3时,脱硫率均可大于80%。实验结果可为实际脱硫装置设计及运行提供必要的基础数据。