固定化酶法生产蔗果低聚糖糖浆技术的探讨

本文探讨了固定化酶生产蔗果低聚糖糖浆的生产技术,研究证明固定化酶可生产60批次,并对生产过程中pH值、灭菌时间、灭菌温度、不同原料糖源的因素进行了探讨,对保质期内产品中蔗果低聚糖(GF2、GF3、GF4)含量的变化进行测定。     

一种新型的功能性低聚糖──蔗果低聚糖及其生产方法

本文报道功能性低聚糖──蔗果低聚糖的生理学性质，在食品中的应用，并阐述了利用β-呋喃果糖苷转移酶（β-fructofuranosidase）固定化生产蔗果低聚糖的流程及方法。     

益生元的生理功能、制造和应用(二)

为了改变消费者的不良饮食习惯,减少环境污染及抗生素的不合理使用而导致的微生态失调,详细介绍了益生元的制备方法,同时介绍了Fm型低聚果糖、GFn型低聚果糖(蔗果低聚糖)、生产蔗果低聚糖的酶、低聚果糖的理化性质和应用、低聚木糖的生理功能和制法、木聚糖酶、低聚木糖的性质和组成.     

蔗果低聚糖的研究和生产应用

蔗果低聚糖是一类天然存在的碳水化合物。研究证明蔗果低聚糖在消化道不被破坏而直达大肠被双歧杆菌等有益菌群选择性利用 ,从而对人体健康产生有益的作用。利用果糖基转移酶 ,可以从蔗糖工业化规模地生产蔗果低聚糖 ,本文对其合成的酶学研究、酶制剂、生产工艺、产品的应用和市场开发等方面进行了综述。     

鳞杯伞α-半乳糖苷酶的固定化及其对豆浆中低聚糖的水解作用

采用海藻酸钠包埋法和壳聚糖交联法固定化鳞杯伞产生的α-半乳糖苷酶,通过比较固定化酶和游离酶的最适pH、pH稳定性、最适温度、温度稳定性、保存时间及两种固定化酶对豆浆中低聚糖的水解作用及操作稳定性等,探究较适宜于鳞杯伞α-半乳糖苷酶的固定化载体。结果表明：鳞杯伞α-半乳糖苷酶最佳硫酸铵饱和度为80%;两种固定化方法酶活性保持率都达到了50%以上,且固定化酶的温度稳定性、pH稳定性、保存时间相比游离酶都有提升;比较两种固定化酶,壳聚糖固定化酶的温度、酸度稳定性及操作稳定性要优于海藻酸钠固定化酶,但保存时间和对豆浆中低聚糖的水解效率要低于后者,两种固定化酶重复使用3次后低聚糖水解率在85%以上,相比于海藻酸钠,壳聚糖更适宜作为鳞杯伞α-半乳糖苷酶的固定化载体。     

海藻酸钠-明胶协同固定化交联漆酶及在鼓泡式反应器中降解双酚A

为了提高漆酶的稳定性,该研究预先将酶与戊二醛反应形成交联漆酶,然后再以海藻酸钠和明胶为载体对交联漆酶进行包埋固定化,考察了影响固定化交联漆酶制备的主要因素。结果显示,当戊二醛的质量分数为2.0%、m(海藻酸钠)∶m(明胶)=1∶1、CaCl₂ 15 g/L时的固定化效果最好,所制备的固定化交联漆酶的稳定性比固定化游离酶有了较大的提高。在鼓泡式反应器中对双酚A的降解试验表明,连续5个批次的反应以后固定化交联酶剩余酶活力为34.93%,双酚A的降解率仍能达到71.13%,分别是固定化游离酶的7.97倍和4.43倍。该研究提供了一种固定化漆酶的新方法,适合重复性和连续性的操作,具有一定的应用潜力。     

细胞-载体共交联固定化葡萄糖异构酶研究 Ⅰ、制备及一般性质

本文介绍用细胞-载体共交联法制备固定化葡萄糖异构酶的方法。有机及无机类载体具有良好的交联特性。将其与含葡萄糖异构酶的游动放线菌菌体混合,在一定条件下用戊二醛交联,可制备具有良好性能的固定化酶。应用正交试验法,选出了适合于该载体的交联条件。因此细胞-载体共交联法制备的固定化酶,得率比无载体法提高三倍,生产成本降低约60％。该固定化酶的柱式连续转化最高活性为6700u/g。异构化生产能力为6.6公斤/每克绝干固定化酶。对该固定化酶的一般酶学性质及工作性能在本文中也做了介绍。     

壳聚糖固定化超氧化物歧化酶的研究

目的:研究壳聚糖固定化超氧化物歧化酶的酶学性质。方法:分别以不同方法对超氧化物歧化酶进行固定并比较其活力,对固定化方法进行相应的优化,对固定化超氧化物歧化酶进行酶学性质测定。结果:以壳聚糖为载体,戊二醛交联法制备固定化超氧化物歧化酶,优化条件下制备的固定化酶,所得固定化酶活力为330U/g,酶活回收率为58.33%,热稳定性和酸稳定性较游离酶有很大的提高,且具有良好的贮存稳定性,固定化酶可实现反复使用,提高了利用率。结论:壳聚糖-戊二醛交联法可用于制备性能较优的固定化超氧化物歧化酶。     

固定化Neutrase中性蛋白酶的研究

以壳聚糖为载体、戊二醛为交联剂固定化Neutrase中性蛋白酶。通过单因素实验，分析了壳聚糖浓度、戊二醛浓度、交联时间对微球制备的影响及戊二醛加入量对酶固定的影响。由正交实验确定制备固定化酶的最佳工艺参数为：壳聚糖浓度为3％、戊二醛与葡胺糖残基摩尔比为1：2、制备微球交联时间为1h，微球与酶振荡吸附12h，再加入2．5％戊二醛交联，使戊二醛最终浓度达到0．9％，制备得固定化中性蛋白酶活力为112．69U／g。固定化蛋白酶的热稳定性和对酸碱的稳定性均较游离中性蛋白酶有所提高。     

壳聚糖固定化树莓超氧化物歧化酶的研究

研究壳聚糖固定化超氧化物歧化酶的酶学性质。分别以不同方法对超氧化物歧化酶进行固定并比较其活力,对固定化方法进行相应的优化,对固定化超氧化物歧化酶进行酶学性质测定。结果表明,以壳聚糖为载体,戊二醛交联法制备固定化超氧化物歧化酶,优化条件下制备的固定化酶,所得壳聚糖酶粉活力为192U/g,酶活回收率为34%,热稳定性和酸碱稳定性较游离酶有很大的提高,且具有良好的贮存稳定性,固定化酶粉可实现反复使用,提高了利用率。壳聚糖-戊二醛交联法可用于制备性能较优的固定化超氧化物歧化酶。     

共固定化生产高含量低聚果糖的研究

生产低聚果糖过程中，副产物葡萄糖抑制酶反应，降低了产物中低聚果糖的含量。本文采用两种固定化方法，通过去除或转化葡萄糖，从而制备出高含量的低聚果糖。首先以２％戊二醛和０．１％丹宁于２０℃时处理固定化黑曲霉菌体与葡萄糖氧化酶，将菌体与酶共包埋得到固定化颗粒，所得到的共包埋产物于５０℃ｐＨ５．０条件下与５０％蔗糖溶液摇瓶反应２４ｈ，得到７１％的低聚果糖；又采用固定化黑曲霉增殖细胞与固定化葡萄糖异构酶协同作用方法，将５０％蔗糖溶液通入柱式反应器，连续生产得到高含量低聚果糖，产物中低聚果糖和果糖含量分别为６３％和１６％。     

Enzymatic synthesis of fructooligosaccharides by inulinases from Aspergillus niger and Kluyveromyces marxianus NRRL Y-7571 in aqueous–organic medium

This work is focused on the synthesis of the fructooligosaccharides (FOS) from sucrose and inulin, using free, immobilized and pre-treated immobilized inulinase from Kluyveromyces marxianus NRRL Y 7571 and Aspergillus niger in an aqueous–organic system. Initially, the influence of pre-treatment using four different gases, propane, n-butane, CO₂ and liquefied petroleum gas (LPG), was investigated towards FOS production and best results were found when both enzymes were previously treated with LPG. The best reaction yields were obtained when the immobilized enzymes were treated with LPG. Considering FOS synthesis using the enzyme from A. niger, yields of 26.62% of GF2 (kestose), 30.62% of GF3 (nystose) and 8.47% of GF4 (fructosyl nystose) were achieved using sucrose as substrate. Using inulinases from K. marxianus NRRL Y 7571, 11.89% of GF2 and 20.83% of GF3 were obtained, using inulin as substrate. However, promising results were achieved using the free form of inulinase from A. niger (77.19% of GF2; 14.03% of GF3 and 0.07% of GF4) using inulin as substrate.     

Recent trends in the microbial production,analysis and application of Fructooligosaccharides

This review focuses on the recent developments in the area of FOS research—its microbial production, functional properties and applications and an overview of the different analytical methods for the determination of the FTase. Different microbial sources of FTase reported in literature to produce FOS with different linkages to form 1-kestose, 6-kestose and neokestose in varying yields based on initial sucrose concentration is discussed. Different fermentative methods have been used for production of FOS. SSF has been used for the production of a value added product FOS utilizing various agroindustrial byproducts. The nutritional and culture parameters when optimized, the FOS yields and productivity could be improved. The use of immobilized enzymes and cells has led to the development of effective and economic methods for large-scale production of FOS. Forced flow Membrane reactor systems, biocatalyst system with a bioreactor equipped with a microfiltration systems, have been used for production of high content FOS by removing the released glucose and unreacted sucrose from the reaction mixture resulting in up to 98% FOS. The use of mixed enzyme system of Fructosyl Transferase and glucose oxidase or glucose dehydrogenase, could produce highly concentrated FOS up to 90–98%. Nano-filtration for removing glucose resulted in FOS of 90% concentration. The purified enzyme was found to produce kestose and nystose unlike the crude enzyme which produced GF₅ and GF₆ oligosaccharides Kinetic parameters (V_m, K_m, and K_i) of the enzyme were determined from experimental data on the transfructosylation rate at various substrate concentrations with and without addition of glucose Techniques like HPLC, using polar-bonded phase and resin-based HPLC columns are commonly used for separation of oligosaccharides with refractive Index Detector or pulsed amperometric detector and annular size exclusion chromatography for large scale and continuous fractionation. Other techniques like gas liquid chromatography, thin layer chromatography, NMR and Mass Spectrometry have been used for structure analyses. The functional properties like use as prebiotics, dietary fiber, role in absorption and defense/Immunity, lipid metabolism control of diabetics have been discussed. A variety of applications in food formulations are also discussed.     

棉织物对甲苯磺酰氯活化法固定化菊粉酶工艺的研究

以4-甲苯磺酰氯活化的棉纤维为载体,对固定化菊粉酶的条件进行探讨。通过对不同纤维成分布料的比较,绒布为载体时得到了较高的固定化酶活。分别采用单因素试验和正交试验,得到优化的工艺参数:每克干基棉布加入10ml干吡啶,对甲苯磺酰氯与干吡啶的比例为1g:1ml,偶联pH值4.5,离子强度0.2mol/L,加酶量80U/g,菊粉酶酶活回收率达到83.60%。在优化的工艺条件下,对糖分组分进行HPLC分析,固定化酶与250g/L菊糖(5U/g菊糖)作用1.5h,低聚果糖含量达到28.21%。     

PEI对固定化增殖细胞性质的影响

以海藻酸钙为载体包埋黑曲霉AS0 0 2 3孢子 ,培养后得到的固定化增殖细胞用于生产低聚果糖 .利用材料试验仪研究了聚乙烯亚胺 (PEI)对固定化增殖细胞强度的影响 ,并研究了PEI对固定化增殖细胞酶活及最适 pH值的影响 .结果表明 ,经PEI处理后 ,尽管固定化增殖细胞酶活略有降低 ,最适 pH值由 5.5降至 4 .0 ,但凝胶强度有明显改善 .起始机械强度由 0 .0 6N/粒增加到 0 .2 79N/粒 ,而机械强度衰减率仅为未处理组的 9.2 7% .     

Production of fructooligosaccharides and β-fructofuranosidase by batch and repeated batch fermentation with immobilized cells of Penicillium expansum

The production of fructooligosaccharides (FOS) and ??-fructofuranosidase (FFase) by immobilized cells of Penicillium expansum was evaluated. In an initial stage, different low-cost materials including synthetic fiber, polyurethane foam, stainless steel sponge, loofah sponge, and cork oak were tested as carrier for the fungus immobilization. Additionally, the influence of the inoculum age (1 or 3?weeks) on cells immobilization, FOS and FFase production was also verified. Synthetic fiber and polyurethane foam were the best materials for P. expansum immobilization (2.21 and 1.98?g/g carrier, respectively) and FOS production (120.3 and 104.8?g/l), and gave also high results of FFase activity (23.01 and 32.42?U/ml). Then, the production of FOS and FFase by repeated batch fermentation with P. expansum immobilized on synthetic fiber was studied, aiming to improve the batch fermentation results. The results obtained in this stage were very promising with FOS yields of 87, 72, and 44?%, in the 3 initial cycles (60?h), respectively; the FFase activity was constant throughout the process (6 cycles, 96?h). Repeated batch fermentation with immobilized cells of P. expansum was found as being a technology with great potential for FOS and FFase production on industrial scale.     

糠醛渣复合材料固定果胶酶的制备

本文以糠醛渣为原始材料进行磺化预处理,利用静自电组装技术将壳聚糖包覆表面,得到糠醛渣-壳聚糖和磺化糠醛渣-壳聚糖复合材料。以FT-IR、SEM等技术对以上制备的复合材料的进行分析表征;然后将两种复合材料利用戊二醛交联后进行果胶酶的固定化。采用单因素变量法研究新型固定化酶的最佳催化性能和稳定性。未磺化糠醛渣复合材料固定酶的最佳催化条件:pH 3.5,果胶酶浓度50 mg/mL,果胶浓度15 mg/mL,反应时间120 min,反应温度45℃;磺化糠醛渣复合材料固定酶的最佳催化条件:pH 3.5,果胶酶浓度20 mg/mL,果胶浓度10 mg/mL,反应时间60 min,反应温度50℃。其中糠醛渣复合材料的固定化果胶酶的最大载酶量为197.20 mg/g,在重复循环使用8次后剩余相对酶活可达81.78%,磺化糠醛渣复合材料的固定化果胶酶在4℃下储存32 d后仍剩余88.98%的相对酶活。两种固定酶都表现出较好的操载酶量和储存稳定性,有较好的经济价值和应用前景。     

Whey protein isolate hydrolysates obtained with free and immobilized Alcalase: Characterization and detection of residual allergens

Protein antigenicity can be reduced by enzymatic hydrolysis, which can be performed either by free or immobilized enzyme. The immobilized enzyme is removed from the reaction medium and reused, while the free enzyme must be inactivated to stop the reaction, generally by heating. Here we have shown that hydrolysates produced with free or immobilized Alcalase on glyoxyl-agarose bead presented different physicochemical properties (hydrophilicity profile, molecular mass distribution, surface hydrophobicity) and different levels of residual milk allergens (α-lactalbumin and β-lactoglobulin). Although, under the studied conditions, the hydrolysis with immobilized enzyme did not reduce the residual allergen levels as efficiently as the free enzyme, the results suggest potential applications of immobilized Alcalase for production of hypoallergenic hydrolysates.     

大孔树脂固定化磷脂酶A1及其用于菜籽油脱胶工艺的优化

选择8种大孔树脂对磷脂酶A1进行固定化,结果表明,离子交换树脂D001的固定化效果最好,其优化的最佳条件为缓冲液pH5.0、酶添加量1.5mL/g、固定化时间4h,在该条件下获得的固定化酶活力为665.8U/g。将固定化酶用于菜籽油脱胶实验,经响应面优化确定最优脱胶条件为固定化酶添加量1.8g/kg、反应时间3.6h、反应温度51℃、反应pH5.5,在此条件下得到的脱胶油中磷含量为5.82mg/kg。将固定化酶重复脱胶5次后,仍保留初始酶活力的47.9%,脱胶油中磷含量为9.78mg/kg。     

An Overview of the Recent Developments on Fructooligosaccharide Production and Applications

Over the past years, many researchers have suggested that deficiencies in the diet can lead to disease states and that some diseases can be avoided through an adequate intake of relevant dietary components. Recently, a great interest in dietary modulation of the human gut has been registered. Prebiotics, such as fructooligosaccharides (FOS), play a key role in the improvement of gut microbiota balance and in individual health. FOS are generally used as components of functional foods, are generally regarded as safe (generally recognized as safe status—from the Food and Drug Administration, USA), and worth about 150€ per kilogram. Due to their nutrition- and health-relevant properties, such as moderate sweetness, low carcinogenicity, low calorimetric value, and low glycemic index, FOS have been increasingly used by the food industry. Conventionally, FOS are produced through a two-stage process that requires an enzyme production and purification step in order to proceed with the chemical reaction itself. Several studies have been conducted on the production of FOS, aiming its optimization toward the development of more efficient production processes and their potential as food ingredients. The improvement of FOS yield and productivity can be achieved by the use of different fermentative methods and different microbial sources of FOS-producing enzymes and the optimization of nutritional and culture parameter; therefore, this review focuses on the latest progresses in FOS research such as its production, functional properties, and market data.