中空纤维酶膜反应器制取麦芽低聚糖的工艺研究

采用聚砜中空纤维酶膜反应器，运用α－淀粉酶和异淀粉酶双酶协同作用酶解淀粉制取麦芽低聚糖的酶膜反应连续化工艺研究。通过对酶膜反应系统的稳态连续操作过程，确定双酶的补加量及反应所要求的温度和糖化补酶时间，确定补实补水关系式，产品质量Ｍ３－６含量达到７０％以上。试验表明酶膜反应连续化新工艺大大节省酶用量及缩短反应周期，提高生产能力。     

利用生物反应器制糖技术开发及成果

生物反应器制糖,是利用酶等生物催化剂,在温和的条件下温度,pH、压力反应。生产可连续化,反应装置小型轻量化,运转操作易自控,节能省力,产品质量稳定。本文介绍日本开发生物反应器制造葡萄糖、麦芽低聚糖、木糖低聚糖、琼脂低聚糖等新技术和成果。     

多酶协同制备低聚异麦芽糖研究

进行了多酶协同制备低异麦芽糖研究，考察了各种α－葡萄糖转苷酶的转苷反应能力，探讨了麦芽糖生成酶及其配合方式以及配合方式以及糖化转苷反应方式对低聚异麦芽糖生成的影响。在此基础上以玉米淀粉为原料研制的低聚麦芽浆中异麦芽糖、潘糖和异麦芽三糖总含量达40％，优于国外同类产品。     

与生产功能性低聚糖相关的酶(下)

介绍了与乳果糖、异麦芽低聚糖、低聚壳聚糖相关的酶及生产。乳果糖又称乳蔗糖,是在蔗糖分子的葡萄糖残基上接一个半乳糖残基构成的三糖,是在蔗糖、乳糖共存下,由节杆菌K-1乳糖苷酶的果糖基转移反应所生产的;异麦芽低聚糖是指含有异麦芽糖、异麦芽三糖、异麦芽四糖和泮糖等具有α～1,6键的分支低聚麦芽糖的混合物,异麦芽低聚糖是以淀粉为原料,经α-淀粉酶、β-淀粉酶或真菌α-淀粉酶的糖化作用生成麦芽糖后,在α-葡萄糖苷酶的转移反应下生成的;壳聚糖是甲壳动物和真菌细胞壁中的甲壳素（几丁质）经碱处理脱乙酰基而成的链状阳离子型多糖,壳寡糖是用壳聚糖酶水解而成的。     

籼米生产低聚异麦芽糖的酶解技术研究

以早籼米为原料采用双酶法生产低聚异麦芽糖浆,本文初步探索各因素对转苷反应的影响,比较了β－淀粉酶与真菌α－淀粉酶的作用差异。结果表明,三个因素对转苦效果的影响大小顺序为：底物浓度＞加酶量＞反应时间。双酶转替中,真菌α－淀粉酶较β－淀粉酶更适宜。     

酶膜反应器及其在食品工业中的应用

酶膜反应器把酶促反应的专一性和膜分离过程高效融合,创造出有利的过程热力学和动力学,因而具有反应和传质速度快、条件温和、选择性高、易于连续化和自动化、操作和设备成本低等特点。概述了酶膜反应器的原理、特点及分类,重点介绍了其在食品工业中的应用。     

超声波影响异麦芽低聚糖生产的研究

研究了超声波处理对固定化酶和游离酶生产异麦芽低聚糖的影响。结果表明,在实验条件下,用５０Ｗ的超声波处理,可使固定化酶活力提高,表现为异麦芽低聚糖有效成分含量提高,而对游离酶反应的效果不明显。     

异麦芽低聚糖生产新工艺的研究

研究了酶法生产异麦芽低聚糖的新工艺，并对影响工艺的主要因素进行了分析。结果表明，采用１３０～１４０ｋＰａ压力的热蒸汽处理淀粉浆后，在９５℃下加酶维持３０～６０ｍｉｎ；采用多酶协同作用糖化工艺，在５８℃和ｐＨ５６条件下反应４０ｈ，异麦芽低聚糖的含量可达５７６％。这也是淀粉（碎米）深加工的有效途径之一。     

低聚异麦芽糖生产及其相关的酶

对低聚异麦芽搪的生产工艺和相关的酶进行了介绍.生产的前提条件是掌握喷射液化技术,包括底物浓度的确定、液化温度和液化酶的选择等.生产的关键工艺是糖化转苷,包括选择合适的糖化酶、α-葡萄糖转苷酶的固定化等.生产用酶有液化酶、糖化酶和转苷酶.     

酶聚合结合超滤技术分离豆腐废水乳清蛋白的工艺研究

为改善豆腐乳清蛋白及低聚糖的回收率、提高膜通量,研究采用转谷氨酰胺酶在豆腐黄浆水自然条件下(温度50℃、pH值6.0)对乳清原液预处理,使蛋白质聚合,方便后续分离工艺选用截留分子量大的超滤膜分离大豆乳清蛋白。数据显示转谷氨酰胺酶Ⅰ可有效催化大豆乳清蛋白聚合,1%的酶添加量50℃反应30min即可催化95%以上的大豆乳清蛋白聚合,酶添加量3‰,聚合时间延长至5h。与对照组相比,乳清采用酶法预处理然后超滤分离,蛋白截留率及膜通量分别提高了2倍和1.3倍,而低聚糖的透过率没有明显影响。试验结果表明,相对于单纯的超滤工艺酶聚合预处理乳清然后超滤的分离效果是显著的。     

脑白金口服液功效成分的鉴别及低聚异麦芽糖含量的测定

目的研究脑白金口服液中功效成分的鉴别方法与低聚异麦芽糖含量的测定。方法脑白金样品经沉淀、离心、固相萃取(solid-phase extraction,SPE)小柱分离、富集和纯化处理。使用化学反应法、薄层色谱法及高效液相色谱法分别鉴别和测定脑白金口服液中低聚异麦芽糖、山楂、茯苓等原料的相关功效成分。同时采用高效液相色谱双柱法测定了低聚异麦芽糖含量。结果乙醇沉淀法、蒽酮法和苯酚硫酸法有效地鉴别了低聚异麦芽糖;高锰酸钾褪色法、薄层色谱法及高效液相色谱法鉴别了山楂中的水溶性枸橼酸;福林酚试剂法、茚三酮显色法分别鉴别了茯苓中水溶性蛋白质及氨基酸。结论上述鉴别和含量测定的方法专属性强、重现性好、灵敏度高,可管控产品质量。     

纳滤法去除低聚异麦芽糖中的单糖

研究了纳滤法去除低聚异麦芽糖中单糖的可行性以及纳滤条件对渗透通量和产品糖组分的影响。得出适宜的纳滤操作条件是:温度25～30℃,操作压力为0.7MPa,料液质量分数为10%。纯化10倍时,低聚异麦芽糖的单糖去除率达98.73%。     

淀粉糖新产品的开发与研究

阐述了国内外应用生物技术开发淀粉糖新产品的现状与前景。     

Improved synthesis of isomaltooligosaccharides using immobilized α-glucosidase in organic–aqueous media

Food Science and Biotechnology - α-Glucosidase was immobilized onto an epoxy-activated resin (Eupergit C) to catalyze maltose into isomaltooligosaccharides (IMO), and then the effects of...     

Effects of oligosaccharides on phase transition temperatures and rheological characteristics of waxy rice starch dispersion

BACKGROUND: The creation of starch‐based foods incorporated with functional ingredients such as probiotics is of great current interest in the food industry. This study aimed to investigate the effects of prebiotic oligosaccharides on the phase transition temperatures and rheological characteristics of waxy rice starch dispersions. Four oligosaccharides were applied to the rice starch dispersions: chitooligosaccharides, fructooligosaccharides, isomaltooligosaccharides and xylooligosaccharides. RESULTS: The addition of 125 g kg^?1 oligosaccharides elevated the onset and peak temperatures for gelatinisation of 200–400 g kg^?1 waxy rice starch dispersions. The temperature of the storage modulus (G′) for gelatinisation increased markedly on adding fructooligosaccharides to 200–300 g kg^?1 waxy rice starch. For gelatinisation of 300 g kg^?1 rice starch dispersion the effectiveness of the oligosaccharides in changing the above parameters was as follows: chitooligosaccharides > fructooligosaccharides > isomaltooligosaccharides > xylooligosaccharides. Moreover, their effectiveness was dependent on the amylose content, as illustrated by comparing waxy and non‐waxy rice starches (amylose contents 9–256 g kg^?1). Importantly, the logarithmic G′₉₅ change was linearly and negatively correlated with amylose content. CONCLUSION: The results suggest that oligosaccharide‐containing rice starch dispersions may potentially be used for the formulation of oligosaccharide‐containing starchy functional foods owing to the rheological changes of these starch dispersions. Copyright © 2011 Society of Chemical Industry     

In situ production and analysis of Weissella confusa dextran in wheat sourdough

Several lactic acid bacteria belonging to the genera Leuconostoc, Lactobacillus, and Weissella have been introduced to wheat sourdough baking for in situ production of exopolysaccharides. This is considered a novel method for improving the shelf-life, volume and nutritional value of bread without additives. However, in situ production of exopolysaccharides during sourdough fermentation is challenged by simultaneous acidification due to metabolic activities of the bacteria, which may significantly diminish the positive technological impact of exopolysaccharides. In this study, the growth, activity and in situ production of dextran by Weissella confusa VTT E-90392 in wheat sourdoughs were investigated. Furthermore, the influence of dextran-enriched sourdoughs, at the addition level of 43%, on the subsequent bread quality was established. W. confusa efficiently produced dextran from the added sucrose in wheat sourdough without strong acid production. A new specific enzyme-assisted method for in situ analysis of dextran in sourdoughs was developed. With this method, we could for the first time proof significant (11–16 g/kg DW) production of polymeric dextran in sourdoughs. Concomitant formation of shorter isomaltooligosaccharides by W. confusa was also detected. The produced dextran significantly increased the viscosity of the sourdoughs. Application of dextran-enriched sourdoughs in bread baking provided mildly acidic wheat bread with improved volume (up to 10%) and crumb softness (25–40%) during 6 days of storage. Hence, W. confusa is a promising new strain for efficient in situ production of dextrans and isomaltooligosaccharides in sourdoughs without strong acidification.     

A Novel α-Glucosidase of the Glycoside Hydrolase Family 31 from Aspergillus sojae

We characterized an α-glucosidase belonging to the glycoside hydrolase family 31 from Aspergillus sojae. The α-glucosidase gene was cloned using the whole genome sequence of A. sojae, and the recombinant enzyme was expressed in Aspergillus nidulans. The enzyme was purified using affinity chromatography. The enzyme showed an optimum pH of 5.5 and was stable between pH 6.0 and 10.0. The optimum temperature was approximately 55 °C. The enzyme was stable up to 50 °C, but lost its activity at 70 °C. The enzyme acted on a broad range of maltooligosaccharides and isomaltooligosaccharides, soluble starch, and dextran, and released glucose from these substrates. When maltose was used as substrate, the enzyme catalyzed transglucosylation to produce oligosaccharides consisting of α-1,6-glucosidic linkages as the major products. The transglucosylation pattern with maltopentaose was also analyzed, indicating that the enzyme mainly produced oligosaccharides with molecular weights higher than that of maltopentaose and containing continuous α-1,6-glucosidic linkages. These results demonstrate that the enzyme is a novel α-glucosidase that acts on both maltooligosaccharides and isomaltooligosaccharides, and efficiently produces oligosaccharides containing continuous α-1,6-glucosidic linkages.     

低聚异麦芽糖的特性及其应用

低聚异麦芽糖是一种新型的功能性低聚糖，由于它具有良好的理化特性和生理功能，近些年其生产发展很快，国内外市场潜力巨大。目前，低聚异麦芽糖主要以淀粉或含淀粉的各类粮食为原料，经多酶协同作用加工而成。本文对低聚异麦芽糖的命名、生产用酶制剂、生产工艺、产品特性及应用等进行了综述。     

Partial characterization of dextran-degrading enzyme obtained from blue cheese

Degradation of dextran beads was observed when the water-soluble fraction of a blue cheese extract was applied to the top of a Sephadex G-150 or G-200 column. This phenomenon suggests the presence of a specific enzyme that can hydrolyze dextran. After removal of casein components from the blue cheese fraction, ammonium sulfate treatment and gel filtration chromatography were performed to isolate the enzyme fraction. The enzymatic products were analyzed by thin-layer chromatography and gel filtration chromatography and identified as isomaltooligosaccharides. The isoelectric point of this enzyme fraction was approximately 4.9, as determined by isoelectric focusing using Rotofor, and the molecular weight of the fraction was 65 kDa, as estimated by sodium dodecyl sulfate (SDS)-PAGE. Optimum pH for enzymatic activity was 5.0 to 5.3. A partial N-terminal amino acid sequence of 20 residues was determined to be ATPDEWRSRSIYFMLTDRGA from an enzyme fraction further purified by ion-exchange chromatography and native PAGE. This sequence showed a maximum homology of 80% with alpha-amylase or Taka amylase that originated from various microorganisms.     

以蔗糖为底物双酶法合成直链糊精

选用蔗糖磷酸化酶和葡聚糖磷酸化酶合成直链糊精,并对工艺条件进行优化。以蔗糖为底物,在添加磷酸盐的条件下,蔗糖磷酸化酶催化反应,生成中间产物葡萄糖-1-磷酸,选用液质联用仪鉴定葡萄糖-1-磷酸的产生;加入麦芽四糖作引物,葡聚糖磷酸化酶催化合成直链糊精,用高效离子交换色谱分析终产物直链糊精的聚合度分布。通过单因素实验,分别研究酶浓度、反应时间、pH及温度对两步反应的影响。蔗糖磷酸化酶催化生成中间产物葡萄糖-1-磷酸的优化工艺条件为:酶浓度4.0 U/mL、反应时间4 h、pH 6.5、温度40℃;葡聚糖磷酸化酶催化合成直链糊精的优化工艺条件为:酶浓度5.0 U/mL、反应时间4 h、pH 4.5、温度40℃。