玉米浓醪酒精发酵工艺的研究

浓醪酒精发酵技术具有高细胞密度、高产物浓度和高速率发酵等特点,能够有效提高发酵终点酒精浓度。本文以玉米粉为原料,利用酿酒酵母对玉米粉浓醪酒精发酵工艺进行了研究。正交试验结果表明,糖化酶添加量对玉米酒精发酵的影响最为显著,料水比及蛋白酶添加量次之。当糖化酶和蛋白酶添加量分别为100 U/g(原料)和150 U/g(原料),料水比为1∶2,酒精浓度达到16.8%vol。另外,添加营养物质甘氨酸、脯氨酸以及肌醇都能有效提高酒精浓度,但甘氨酸添加效果优于脯氨酸和肌醇。当甘氨酸添加浓度为2 g/L时,发酵液酒精浓度达到17.7%vol。     

Asp.niger.no.882生淀粉糖化酶性质及动力学的研究

在淀粉原料发酵生产酒精传统工艺中,原料蒸煮耗能约占全部酒精发酵生产能耗的30—40％,因此砍掉蒸煮工序,节约能源、节约投资和降低成本是开发酒精发酵的新课题。解决办法之一是采用无蒸煮发酵法。从理论上讲无论淀粉是熟的还是生的,只要被转化成可发酵性糖,就能被酵母利用。这一转化有赖于生淀粉糖化酶的作用。目前国内外无蒸煮酒精发     

玉米原料无蒸煮发酵酒精工艺的研究

利用筛选的糖化酶作为糖化剂，进行玉米无蒸煮发酵酒精的试验，确定了糖化酶的最适添加量为100u／g原料，料水比1：2，自然pH，以过40目筛的玉米粉为原料，活性干酵母添加量0.3％，30℃条件下恒温发酵60～70h，发酵醪酒精度达15％。外加氮源或酸性蛋白酶对发酵有促进作用，可使酒精度达16％，原料的淀粉利用率达88％左右，在15L发酵罐的扩大试验中也取得了较好的效果。发酵过程还原糖始终处于较低水平，有效地抑制了杂茵，使发酵得以顺利进行。该工艺显著地节省了酒精生产过程中的能源消耗，它对进一步提升酒精在我国能源结构中所占的比重具有重要意义。     

利用低温蒸煮工艺进行高浓度酒精发酵

本研究利用低温蒸煮工艺,探讨了玉米淀粉的高浓度酒精发酵。在80℃下对玉米粉进行蒸煮15min,同时加α—淀粉酶进行液化。经冷却后,在55℃下加糖化酶糖化30min。再度冷却到30℃,加酵母菌悬液发酵70h。并利用这一技术研究了产高浓度酒精酵母菌株的最佳发酵条件。在加糖化酶量200～300u/g原料。酵母接种量为3％(v/v),发酵温度为30℃,pH4～4.5,发酵周期为70h,原料水比为1:2条件下,所选用的菌株之一W_4可以产生17.5％(v/v)乙醇。发现该菌株在发酵速度和耐酒精能力方面明显地优于国内酒精厂常用的酵母菌株1300。在发酵结束时,成熟发酵醪的pH值为4.2。外观糖度为0(Bx),残还原糖为0.19％,残总糖为3.6％,淀粉利用率为90％。     

微波预处理木薯发酵酒精的研究

利用微波预处理木薯代替传统酒精发酵生产中的蒸煮液化工艺,并对微波预处理后的木薯进行无蒸煮发酵工艺的研究。通过正交试验,得出微波处理后的木薯最佳发酵条件为：料水质量比1:2.8,糖化酶添加量180U/g,活性干酵母添加量为原料质量的0.3%,氮源用量为原料质量的0.3%,30℃发酵72h,发酵醪液的酒精体积分数达到12.7%。通过与传统蒸煮液化工艺进行能耗对比,至少节省30.8% 的能耗。     

荔枝核发酵酒精的工艺研究

利用荔枝核进行酒精发酵,对蒸煮、液化、糖化和发酵等工艺进行了研究。结果表明,荔枝核经干燥粉碎后加水比为1：4,用硫酸调节pH到2．0后,再110～120℃高温高压蒸煮1h,再调节pu到6．0,添加α-淀粉酶40u／g进行液化,调节pH到4．0,添加糖化酶120u／g进行糖化,随后接种安琪超级酿酒酵母0．04％,在温度为30℃条件下发酵,可使酒精得率最高。在发酵过程中添加适量硫酸铵可加快发酵速度,缩短发酵时间。     

酒精浓醪发酵生产工艺的优化

以玉米粉为原料，AY-15为发酵菌种，在浓醪发酵条件下，对氮源添加、糖化工艺和发酵条件进行了研究。结果表明，在酒精发酵过程中添加适量氮源，可明显提高酵母细胞的数量和发酵能力，缩短发酵周期12h；优化的糖化工艺为糖化酶用量150u/g原料，糖化时间60min；最适的发酵条件为初始pH值5．0，发酵温度33℃。     

玉米粉高浓度酒精发酵的研究

本研究以玉米粉为原料，利用一株具有高酒精耐性的酵母菌进行浓醪发酵。通过对比和初步探索，改革了原低温蒸煮后需经过糖化的工艺路线，确定了低温蒸煮后糖化发酵并行的生产工艺，减少了糖化设备投资，缩短了原料处理时间，同时在原料加水比１：２．０，发酵温３０℃，糖化酶加量１００￣１５０ｕ／ｇ，酵母接种量９％（ｖ／ｖ）的情况下，这株酵母菌在６０小时内可以产生１４．８％（ｖ／ｖ）的酒精，成熟发酵醪中的ｐＨ为５，残还     

国内外生淀粉糖化酶的研究及应用概况

<正> 淀粉糖制造或酒精、有机酸发酵等实现节能型无蒸煮糖化工业化的关键在于能否获得能使谷粒中的生淀粉进行有效水解的糖化酶。近年来,越来越多的研究者对此进行了卓有成果的研究。这些研究主要包括对生淀粉糖化酶产生菌的筛选和对生淀粉糖化酶作用机理的探讨     

低脂玉米粉无蒸煮液态发酵制酒精技术初探

论述了用低脂玉米粉无蒸煮液态发酵新工艺制取酒精的工艺流程、操作及主要技术参数,提出用低脂玉米粉生产酒精其综合效益高于薯类原料及玉米整粒。     

Multiple Forms of Glucoamylase of Rhizopus Species

The glucoamylase system of Rhizopus sp. was fractionated into two kinds of glucoamylase by using the corn starch adsorption technique supplemented by CM-cellulose chromatography. One of these fractions, referred to as glucoamylase I, has a strong debranching activity and is highly active in raw starch digestion. The raw waxy corn starch digestion by glucoamylase I was accelerated by adding a-amylase from Rhizopus sp. or from Aspergillus oryzae. The raw non-waxy corn starch digestion by glucoamylase I was more difficult than the raw waxy corn starch digestion, which was also accelerated by adding α-amylase from Aspergillus oryzae. On the other hand, another fraction, referred to as glucoamylase II, has a weak debranching activity and can not be adsorbed on raw starch. The raw waxy corn starch digestion by glucoamylase II was very weak, but was accelerated by adding α-amylase from Rhizopus sp.     

Change in Digestibility of Gamma-Irradiated Starch by Low Temperature Cooking

Combination effect of irradiation and low temperature cooking on starch digestibility has been investigated as a basic research for application of radiosterilization on starch fermentation. The digestion of corn starch by glucoamylase after cooking at low temperature was enhanced by γ-irradiation and the required cooking temperature was decreased from 75-80°C to 65°C by 25 kGy. Gelatinization of starches except tapioca starch was enhanced by irradiation and it corresponds to the digestibility. The digestibility of potato starch which has a high viscosity was especially enhanced at low temperature cooking because the viscosity was markedly decreased by irradiation. These results show that the irradiation of starches is useful not only for the sterilization of fermentation broth but also for the enhancement of digestion.     

膨化玉米粉制糖技术研究

研究了膨化玉米粉的液化、糖化和精制方法,获得了膨化预糊化、中温酶液化、筛滤法麸质分离的玉米制糖新工艺。结果表明,膨化玉米粉可使淀粉液化收率提高7.82%,糖化时间缩短16.7%,糖化最终DE值达97.4。与湿法淀粉制糖工艺相比,新工艺可降低生产成本约20%,是一条节能、节水、环保、综合效益好的制糖新技术。     

Fractionation of the Glucoamylase System from Black-koji Mold and the Effects of Adding Isoamylase and Alpha-amylase on Amylolysis by the Glucoamylase Fractions

The glucoamylase system of black koji mold was fractionated into four kinds of glucoamylase by using the corn starch adsorption technique supplement by DEAE-cellulose column chromatography. One of these fractions, referred to as glucoamylase I, had a strong debranching activity and is highly active in raw starch digestion. The raw waxy corn starch digestion by glucoamylase I was accelerated by adding α-amylase or isoamylase. The raw non-waxy corn starch digestion by glucoamylase I was accelerated by α-amylase but not so much by isoamylase as by α-amylase. On the other hand, another fraction, referred to as glucoamylase II, had very weak debranching activity and was most feeble in the digestion of raw starch. The raw waxy corn starch digestion by glucoamylase II was very weak, but was accelerated extremely by adding isoamylase, but not by α-amylase.     

产糖化酶根霉菌的分离及其酶学性质研究

从五粮液酒厂周边采集土样中分离出6株产糖化酶且酶活较高的菌株,选取酶活最高的1株K-1为出发菌,进行发酵实验和酶学性质研究,结果表明,糖化酶酶活在50～55℃较高,最适作用温度为55℃;糖化酶在pH5.5～6之间酶活力较高。酶对玉米粉、小麦粉、木薯粉、苦荞粉、黄豆粉有较强的液化能力,其中对玉米粉的糖化能力最强。在酶的动力学实验中测得Km=1.446 mg/mL,Vm=0.269 mg/mL.min。     

酶预处理和酸水解制备糯玉米淀粉纳米晶及其表征

采用糖化酶对糯玉米原淀粉进行预处理,通过X射线衍射(XRD)确定糖化酶预处理的最佳用量,再对酶预处理淀粉进行硫酸酸水解,制备糯玉米淀粉纳米晶,采用傅里叶变换红外光谱（FT-IR）、扫描电子显微镜(SEM)、粒径测量和Zeta电位分析等对淀粉纳米晶进行表征。结果表明,用1000U/(g淀粉)活性的糖化酶对糯玉米原淀粉处理2h,再结合酸水解2天,得到粒径约100nm、分散性好、产率为24.1%的糯玉米淀粉纳米晶;相较于仅硫酸酸水解处理,酶预处理结合酸水解法制备糯玉米淀粉纳米晶的反应时间缩短了3天,产率提高了70.9%,淀粉纳米晶的Zeta电位达-22.3 mV。     

Hydrolysis of Native Wheat and Corn Starch Granules by Glucoamylases from Aspergillus Niger and Rhizopus Niveus

The action of glucoamylase I and II (α-1,4-glucan glucohydrolase, E.C. 3.2.1.3) from Aspergillus niger and the glucoamylase from Rhizopus niveus on native wheat and corn starch granules was followed by using scanning electron microscopy (SEM) and by measuring the glucose released by enzymatic attack. Two distinct patterns of attack were observed. Glucoamylase I and the glucoamylase from R. niveus attacked the granule surface relatively uniformly, resulting in large disclike depressions. Glucoamylase II, while showing some disc-like depressions, produced small grooves (furrows) in the surface of the granule. Similar patterns were observed for both corn and wheat starch granules, except that attack by glucoamylase I and the glucoamylase from R. niveus on wheat starch granules also developed along the equatorial groove (not easily seen until the granules were exposed to enzyme solutions). Measuring glucose released indicated that hydrolysis by glucoamylase I and by the glucoamylase from R. niveus were nearly equal in extent and were about twice that by glucoamylase II.     

生物酶法制备蜡质玉米淀粉纳米晶及其表征

淀粉纳米晶是从天然淀粉中制得的一种纳米尺寸的聚多糖晶体。本试验通过糖化酶部分酶解蜡质玉米淀粉,并对其进行超声波处理,离心后经真空冷冻干燥得到淀粉纳米晶。采用扫描电子显微镜、激光粒度分布仪、X-射线衍射、傅里叶红外光谱等手段对淀粉纳米晶进行表征。结果表明:淀粉纳米晶颗粒表面粗糙,颗粒之间由于静电引力相互聚集;酶解得到的淀粉纳米晶的粒径集中在100 nm左右,结晶度为75.86%,产率达到27.53%。酶法制备过程对环境无污染,是一种新型的纳米晶绿色制备技术。     

响应面法优化富含鱼骨钙低温鱼肉香肠配方

通过响应面法对富含鱼骨钙低温鱼肉香肠配方进行优化。采用单因素实验,探究食盐、鱼骨粉及玉米淀粉对富含鱼骨钙低温鱼肉香肠质构特性、感官品质和蒸煮损失的影响。在此基础上,进行Box-Behnken响应曲面设计,通过响应面试验确定三种添加剂最佳添加量为:食盐2.5%、鱼骨粉1.5%、玉米淀粉6%,按照此优化配方制作的产品表面紧致,切面光滑无气泡,鱼肉香味浓厚,感官评分为88.55分,蒸煮损失率为3.51%,与模型预测值吻合率分别达到99.49%和98.86%,为进一步研究开发鱼肉香肠提供了一定的理论数据支持。     

复合酶法制备多孔淀粉条件的优化

采用α-淀粉酶和糖化酶复合水解法,以玉米淀粉为原料制备具有较高吸油率的多孔淀粉,研究了复合酶的作用条件对多孔淀粉吸油率和得率的影响,通过测定多孔淀粉的吸油率及扫描电镜分析,对多孔淀粉制备条件进行了优化.试验结果表明,α-淀粉酶在50℃、pH 6.0、水解14 h后,再在pH 4.0、50℃加入糖化酶水解14 h,α-淀粉酶和糖化酶配比为1:2,总酶量为2%时,制得多孔淀粉的吸油率56.62%、得率88.79%.扫描电镜结果显示淀粉颗粒表面小孔分布均匀,孔径适中,孔较深.