从低木糖含量母液中提取晶体木糖醇的实验研究

以低木糖醇含量的木糖醇母液为原料,采用过冷结晶和添加溶剂分离的技术对木糖醇母液进行提纯.先将低木糖醇含量母液浓缩处理,加入晶种后进行长时间结晶孕育,再将初次结晶得到的晶体木糖醇进行重结晶得到最终产品.实验结果表明,木糖醇母液浓缩折光度为80～82,温度降至6～8 ℃后加入5%的晶种进行初次结晶的收率最高,可达到23%,纯度可达到96.6%,再通过重结晶可以将纯度提高到98.5%以上,达到国家标准.     

利用L-阿拉伯糖结晶母液回收L-阿拉伯糖的研究

L-阿拉伯糖母液是生产L-阿拉伯糖之后残余的糖液,其L-阿拉伯糖含量54%~57%,直接进行二次结晶十分困难,作为废料处理又造成极大的浪费。采用脱色、离子交换脱盐与真空结晶相结合的方法能够提高从L-阿拉伯糖母液回收L-阿拉伯糖的回收率。本工艺中L-阿拉伯糖母液,经过脱色后,透光度由20.6%提高至83.5%;经过离子交换脱盐后电导率降低90%;浓缩、真空结晶得到L-阿拉伯晶体含量84.1%;重结晶后,L-阿拉伯糖含量98.5%。采用本工艺可以将L-阿拉伯糖的收率提高30%以上,回收得到的晶体经过重结晶后可以得到高品质产品。     

黄原胶发酵液的提纯浓缩研究

本文采用过滤与超滤工艺对黄原胶进行提纯和浓缩研究,研究结果表明,黄原胶发酵液经过滤与超滤处理可去除发酵液中悬浮的不溶性固形物和可溶性离子物质。产品得到提纯并可获得浓度为8.7％的黄原胶浓缩掖。提纯和浓缩后的黄原胶具有良好的增粘性,触变性和冷热稳定性。     

酸水解玉米芯制木糖醇

以玉米芯为原料 ,用酸水解 ,经中和、蒸发、脱色、离子交换、加氢、浓缩、结晶并将母液进行再处理可生产出木糖醇 .采用正交试验法研究了水解条件对木糖醇得率的影响 :在最佳生产工艺条件下 (水解压力 0 0 5MPa ,水解温度 12 0℃ ,加H2 SO4 浓度为 1 5 % ,水解时间 4h) ,木糖醇得率可达6 2 2 % .     

杨梅腌渍液脱盐及制备浓缩果汁的研究

研究了在真空浓缩过程中,杨梅腌渍液中的还原糖、总有机酸和氨基态氮含量的变化,开发出两步真空浓缩结晶脱盐和两步离子交换法对杨梅腌渍液进行脱盐,制备低盐和无盐浓缩果汁的工艺,实验表明:两步真空浓缩结晶法可除去腌渍液中80%~85%的盐,间歇式离子交换法可将浓缩母液的盐含量降低至1.5%左右,脱盐率达90%以上,再经连续式离子交换脱盐可制备无盐的浓缩果汁类饮料。     

从赤藓糖醇生产废弃母液中回收赤藓糖醇

赤藓糖醇生产废弃母液的成分分析表明,母液中固形物含量约为70%,其中赤藓糖醇约占干物的30%,灰分约占干物的20%,检测不到葡萄糖。液相色谱分析结果表明,母液中有机固形物除赤藓糖醇外,还含有另外2种未知糖醇组分。实验主要探讨了从赤藓糖醇生产废弃母液中回收赤藓糖醇的可行性,重点考察了废弃母液的脱盐效果及其对赤藓糖醇回收的影响。以交换容量和产物的吸附为考察指标,筛选出D315和001*7阴阳2种离子交换树脂用于母液脱盐除杂,采用双柱串联工艺,活性炭脱色处理后的母液脱盐率可达98.5%。经减压蒸馏、降温结晶,母液赤藓糖醇结晶回收率达47.3%,纯度达99%以上。     

苹果汁冷冻浓缩与真空蒸发浓缩效果的对比

基于悬浮结晶式冷冻浓缩仪,将传统上相互分离的单元操作——刮面换热器、结晶器和洗涤柱整合,研发具有三位一体紧凑结构的多级智能化冷冻浓缩仪。采用该冷冻浓缩仪对苹果汁进行冷冻浓缩,并以真空蒸发浓缩作对比分析。结果表明:单级浓缩比约为1.8;经三级冷冻浓缩后苹果汁可溶性固形物含量由初始的10.5°Brix增加至34.5°Brix;VC和芳香物乙酸丁酯的保留率均在90%以上;同时对还原糖的破坏和果汁颜色的影响很小;此外,可溶性组分在冰晶和母液中的分配系数为0.008 1～0.067 0;三级冷冻浓缩后对应的可溶性固形物回收率约为98%。对比分析结果表明,当苹果浓缩汁可溶性固形物含量为33.6°Brix时,真空蒸发浓缩苹果汁的VC保留率为84.5%,芳香物乙酸丁酯保留率为43.9%。就苹果汁营养及风味保存而言,冷冻浓缩远优于蒸发浓缩。     

顺序式模拟移动色谱分离木糖醇母液的前处理工艺研究

以木糖醇母液为研究对象,研究顺序式模拟移动色谱分离木糖醇母液的前处理工艺。利用单因素与响应面法对木糖醇母液的前处理工艺进行优化,在单因素试验基础上,考察活性炭添加量、脱色温度、脱色时间、脱盐方式等因素对木糖醇母液脱色率的影响,再根据Box-Behnken试验设计原理,采用响应面方法优化木糖醇母液脱色条件,考察离子交换脱盐的顺序与洗脱流速对木糖醇母液脱盐的影响。结果显示:顺序式模拟移动色谱分离木糖醇母液的前处理工艺参数为:木糖醇母液浓度为25%,活性炭添加量3.71%,脱色温度59℃,脱色时间1.77h,木糖醇母液的脱色率达到93.5±0.5%。离子交换脱盐的顺序为阴-阳-阴,洗脱流速为30m L/min,母液的电导率为25.5±0.5μS/cm。经本工艺处理得到木糖醇母液达到了顺序式模拟移动床分离木糖醇母液的进料要求。     

预处理猪血清IgG料液的超滤浓缩研究

本实验对预处理猪血清IgG料液超滤浓缩进行了研究.选择螺旋卷式超滤设备,以截留液全循环错流方式对预处理IgG料液进行超滤浓缩.其最佳工艺参数为:样品pH值为7、温度50℃、超滤压力0.1MPa、浓缩倍数为10倍.浓缩后得到的样品中蛋白质含量为2.08%(W/V),IgG含量为1.42%(W/V),具有活性的IgG所占比例比超滤前略有下降,从91.3%降低到87.6%.     

色谱分离树脂在木糖醇母液中的应用研究

将色谱分离技术应用于木糖醇母液,再次回收母液中的木糖醇,通过选定吸附剂,研究了流速、温度以及进料浓度对木糖醇母液的分离影响情况,结果表明,应用于木糖醇母液的合适的色谱分离树脂及其最佳分离条件是:其树脂型号为CR-Ca型,流速1.0BV/h、温度70℃、浓度45%～50%;对1吨木糖醇含量54%的母液进行试生产,得到木糖醇晶体约70Kg,为色谱分离技术在木糖醇母液中的应用提供了一定的理论参考依据。     

结晶母液回收D-对羟基苯甘氨酸的工艺优化研究

D-对羟基苯甘氨酸（D-HPG）是合成甜味剂、药物的重要中间体，为降低工艺成本，提高产品质量，提出了一种结晶母液回收D-HPG的连续色谱新工艺。优选纳滤膜进行前处理，增浓结晶母液，筛选Applexion NF200纳滤膜增浓D-HPG效果较好。通过单柱实验筛选连续色谱系统填料树脂，其中Applexion XA945树脂对D-HPG和硫酸铵分离度可达16。进一步对色谱系统的分离效果进行研究，结果表明，经连续色谱分离后，进料液中D-HPG平均纯度由42.2%提高至96.3%，平均收率达91%。利用连续色谱系统从结晶母液中回收D-HPG，是较有前途的工艺。与传统工艺相比，新工艺既保证了D-HPG总收率，又降低其工艺成本，提高了产品质量。     

木糖和木糖醇SMB色谱分离过程建模与优化

利用模拟移动床 (SMB)连续色谱技术分离木糖醇母液中的木糖和木糖醇组分 .在平衡理论的框架下 ,提出了使用基于相应的真实移动床 (TMB)的简化数学模型研究各进料液和产品流出液的流量等操作参数的变化对SMB分离性能 (以纯度和收率作为性能指标 )影响的方法 ,并采用该方法进行了操作条件寻优仿真 ,取得了满意结果 .在实验室SMB分离设备上 ,基于此最佳操作条件所得到的木糖和木糖醇产品液纯度和收率均达到 1 0 0 % .     

Clarification of date juice

Summary This study was initiated to utilize a variety of low quality dates (Qish‐Habash) so that high quality syrup could be produced by modifying the clarification process of the date juice. Five different clarification treatments were used: (1) filtration, (2) hot liming and filtration, (3) cold liming and filtration, (4) powder‐activated carbon and filtration, and (5) granular‐activated carbon and filtration. The sugar content, total soluble solids, total ash, pH, colour and purity were analysed to determine the clarification effects. The clarified juices produced by these treatments were evaporated under constant conditions to produce date syrup. Filtration, and activated carbon and filtration were the most successful treatments for the clarification of the date juice. Filtration gave the highest improvement in syrup purity (97.7%), due to the reduction of total ash by 19.5% and colour by 44.6%. Activated carbon removed the juice colour to give the lowest amount (60% in powder form and 57% in granular form), as well as reducing total ash, which led to an improved syrup purity, 92.2% in powder form and 91.4% in granular form. Liming clarification had undesirable effects, by increasing the total ash (15% in hot and 17% in cold lime), and increasing the colouring matter produced by decomposition.     

蔗糖水解制取结晶果糖技术研究

为提升制糖产业的综合效益,以白砂糖为原料开发附加值更高的结晶果糖,探讨用蔗糖原料制取高纯度结晶果糖的最优工艺方法.实验以高浓度蔗糖液(55％w/w)为原料,食品酸味剂柠檬酸为水解剂,通过蔗糖水解、脱色、阴阳离子树脂除盐,以钙型树脂分离、纯化果葡糖液,在常温下得到结晶果糖和结晶葡萄糖.实验优化蔗糖最佳水解工艺条件:水解温...     

木糖母液微生物脱除葡萄糖及回收木糖

木糖生产过程中产生大量的木糖结晶母液。由于其杂糖含量较高，仅通过常规的浓缩，结晶等步骤，很难从中回收得到结晶木糖。本研究采用酵母发酵技术，先脱除木糖母液中的葡萄糖等杂糖，再结合真空浓缩与冷却结晶工艺，可以再析出晶体木糖，收率约25％。微生物脱除葡萄糖技术同样可用于玉米芯水解液中葡萄糖的有效去除，以提高木糖的结晶得率。     

Continuous production of very enriched fructose syrup by the conversion of glucose to ethanol from glucose-fructose mixtures in an immobilized cell reactor

The yeast Saccharomyces cerevisiae ATCC 36859, which preferentially utilizes glucose in glucose-fructose mixtures, was immobilized and used for the continuous production of very enriched fructose syrup. A syrup containing fructose as 99% of the reducing sugars was produced from a 10.1% w/v glucose and 9.8% w/v fructose mixture at a dilution rate of 0.106 h⁻¹. Later in this process when the dilution rate was increased to 0.366 h⁻¹ the ethanol productivity was 12.7 g 1⁻¹ h⁻¹. This is 16% less than the value attained in a similar medium containing only glucose as the carbohydrate. The fructose content was also increased from 55 to 95% of the reducing sugars in a food grade mixture of high fructose corn syrup and Jerusalem artichoke juice. Purification of the product with activated carbon and ion-exchange resin produced a stable, colourless and very enriched fructose syrup suitable for human consumption.     

Kinetic Analysis of Osmotic Dehydration Carried Out with Reused Sucrose Syrup

ABSTRACT Processing times required to achieve a target level of soluble solids were determined in apple pieces during sequential osmotic dehydrations carried out with reused sucrose syrup, in which new loads of fruits were charged in each turn. Effective diffusivities for water and sucrose in apple pieces were experimentally determined as a function of syrup soluble solids. A computer program was written to predict soluble solids change both in apple pieces and in syrup during the sequential osmotic dehydration process. Experimental data on the change of soluble solids for apples and syrup for 10 batches arranged in 2 sets of 5 were obtained. A good agreement between observed and predicted values of soluble solids in both fruit and the syrup was obtained, with root mean square values ranging from 1.3% to 4.6%.     

Characteristics of Frozen Desserts Sweetened with Xylitol and Fructose

Combinations of xylitol, fructose and 24 DE corn syrup solids (CSS) were the sweetening agents in ice cream-type frozen desserts. A 2³ factorial experimental design evaluated the most acceptable combinations of xylitol (4% or 6%), fructose (4% and 6%) and CSS (10% and 12%). Based on chemical, physical and sensory analyses of the eight experimental combinations it was demonstrated that a formulation involving 6% xylitol, 6% fructose and 10% CSS gave product acceptability similar to that of an ice cream with conventional ingredient array and composition.     

Fractionation of Nonfat Dry Milk Powder into Protein and Lactose Products

Five processes were used to fractionate low heat NDM into a number of products including crude casein, three types of lactalbumin, crude lactose, United States Pharmacopeia-grade lactose, and a partially deproteinated whey product. Regular lactalbumin and crude lactose were produced by process 1 with a total recovery of 91% of starting NDM solids including those obtained from the casein fraction. Process 2 led to the production of both high and low ash lactalbumin and crude lactose, but the total solids recovery was about 10% lower than process 1 due to extra material handling. Both Processes 3 and 4 allowed for the crystallization of crude lactose from condensed whey containing the full protein complement. Process 4 was similar to process 3 except provision was made to return the mother liquor from the United States pharmacopeia lactose preparation back to the starting casein whey; this increased the solids recovery from 91 to 96%. The fifth process was used to purify the crude lactose of processes 1 to 4 for the preparation of United States Pharmacopeia grade lactose.