宁城糖厂用栲胶—磷酸三钠法处理蒸发罐用水

我厂第一次原糖加工热力系统采用的流程是:清净后的糖汁直接进入后两效蒸发罐进一步浓缩,锅炉来的蒸汽供一、二砂煮糖和一效蒸发罐用汽,蒸发罐产生的二次汁汽供三、四砂煮糖和工艺用水加热,经生产实践证明,这种流程不适合宁城糖厂的具体情況。糖浆走蒸发后,锤度平均提高15.0％,而色值也平均提高11.3°st,经测定蒸发糖份损失在正常操作条件平均约为     

糖厂蒸发过程热能决策管理DCS控制系统

本文主要介绍糖厂蒸发过程DCS控制系统的组成与功能;蒸发罐液位、末效糖浆浓度等参数的准确测量方法;建立末效糖浆浓度与各有关参数的数学模型,通过数学模型的控制方式达到末效糖浆浓度的精确控制;研究蒸发罐液位多参数模糊控制算法来控制蒸发罐的液位,使蒸发罐液位控制更稳定。     

糖厂蒸发系统的控制逻辑及蒸发罐的结构改进

蒸发系统的自动控制是糖厂DCS控制系统的一个最重要部分,很多糖厂即使没有做全厂DCS系统但却首先建立了蒸发站的局部DCS控制。本文介绍了蒸发系统的正确控制逻辑,建立蒸发罐的液位、末效真空度、蒸发糖浆锤度、加热蒸汽用量、清汁箱液位等各控制参数的逻辑联系和集成控制方案。     

糖厂中和pH值在线测量、控制系统的新方法的研究

本文对糖厂中和pH值的测量、在线控制系统进行了分析,指出了目前在控制系统中普遍存在的问题：pH电极在清洗、标定方面不同程度地存在维护量大的问题。因此,提出了一种新型的设计方法一一将图像处理系统应用到pH值的控制系统中。     

pH对白砂糖转化糖浆色值的影响

色值是转化糖浆的一个重要质量指标。它直接影响到绵白糖的质量,本文比较了不同水解pH值及中和pH值对转化糖浆制备工程色值的影响,并选择了转化糖浆制备过程的最佳pH值。     

差压式糖浆锤度计的设计和制作

以前有关单位曾把差压式锤度计介绍给糖厂作为末效糖浆锤度检测,由于各种原因造成效果不够理想而停止使用。其实,差压式锤度计简单实用,只要设计合理、制作精细,用于糖浆锤度检测,对比其它形式的锤度计更加直接、简单,而且     

锑电极及pH自动调节

我厂是亚硫酸法中型厂,1966年开始使用玻璃-甘汞电极系统(简称玻璃电极系统)来测量中和汁 pH 值。由于糖汁中杂质在玻璃电极上迅速出现结垢,15分钟便开始反应迟钝。后虽加装清洗器,使用时间也只延长至数小时,且易损破电极,未能正常使用。1971年我们改用锑-甘汞电极自动调节系统(简称锑电极系统),目前使用时间能延长到16～20天才需清理一次;测量精度在0.2pH 左右;自动控     

降低绵白糖中5-羟甲基糠醛含量的研究

研究了绵白糖生产用转化糖浆制备过程中影响5-羟甲基糠醛（5-HMF）形成、蔗糖转化率以及糖浆色值的因素,并通过正交试验,优化出酸法水解蔗糖生产转化糖浆的工艺条件,即糖浆锤度为75°B,pH值1．5,温度75℃,反应时间60min。在优化条件下每百克转化糖浆含有3．02mg5-HMF,糖浆色值为93．9IU,蔗糖转化率达到91．5％。     

应用双金属结构技术对蒸发罐进汽阀门的改造

1存在问题莆田糖厂生产能力为日榨甘蔗4500吨，I效蒸发罐进汽管道配有φ500直角阀，用于控制1效蒸发罐的进汽量和蒸发罐的运行或停罐轮洗。1．阀座2．铜图图1改造前φ500直角间间体图当I效蒸发罐运行一个时期以后，加热管内沉积的罐垢多了，必须对蒸发罐进行停罐轮洗。但是由于φ500直角阀密封性能差，（见图1所示），虽然关闭阀门，却不能彻底切断汽源，还有少量的蒸汽继续不断地往I效蒸发罐汽鼓渗漏，影响蒸发罐按照作业计划停罐清洗。为此，曾经多次求援制造厂家返工处理，但是返工费用昂贵，质量也未能保证，渗漏依然存在。生产中，Q5…     

糖浆气浮工艺条件的研究

研究了糖浆气浮工艺中磷酸加入量、预灰pH值、硫熏强度、硫熏中和pH值等因素对糖浆脱色率和气浮效果的影响,并对几种因素进行正交试验研究,确定了最佳气浮工艺条件的组合方案,结果表明最佳工艺条件是磷酸加入量为800mg/kg,预灰pH7.5,硫熏强度12ml,硫熏中和pH8.5。     

振荡多晶体冰糖结晶工艺研究

研究了糖浆沸点与锤度的关系,结果表明两者呈线性相关.在多晶体冰糖保温静止结晶的基础上,研究了浓缩终点温度和糖浆pH对基于振荡的多晶体冰糖结晶工艺的影响,得出浓缩终点温度最低为115℃,此时的锤度为83.1° Bx,过饱和度为1.2;当浓缩终点温度为120℃时,最终冰糖的结晶率为71.91％;煮糖所用糖浆的适宜pH范围为...     

蒸发过程糖汁中热敏性物质变化特性的研究

为了更好地制定糖汁澄清工艺条件并为煮糖系统提供高品质的糖浆,本实验研究测定了碳酸法糖厂蒸发过程糖汁中热敏性物质的含量,探索它们的变化规律并分析其致因。结果表明,随着蒸发效数的增加,糖汁pH先升后降,整体下降0.37～0.78;纯度、钙盐、氨基酸态氮及酰胺有所下降;还原糖及色值含量变化呈上升趋势。碳酸法糖厂二碳饱充pH不宜过低,清汁的pH宜控制在中性偏碱。     

赤砂糖回溶糖浆硫酸镁—聚硅酸锌法脱色工艺及其机理研究

以赤砂糖回溶糖浆为研究对象,研究了高pH条件下硫酸镁和两性含2%二氧化硅聚硅酸锌对回溶糖浆的脱色效果及机理。在单因素试验基础上,采用响应面分析法对脱色条件进行优化,获得最佳条件为:镁离子用量500mg/L、含2%二氧化硅的聚硅酸锌用量1.57%、pH值11、温度30℃。该条件下脱色率高达92.36%。采用扫描电子显微镜(SEM)和电位分析仪对混凝物和糖汁体系进行了表征,结果表明脱色机理为电中和吸附。     

蔗糖汁高糖发酵条件及糖代谢研究

以高浓度蔗糖汁(锤度大于25°BX)为培养基,以耐酒精、耐高糖的酿酒酵母为菌种,对发酵条件即发酵液初始糖锤度、发酵温度、发酵液初始pH值、接种量进行单因素和正交试验优化。结果表明：在锤度30°BX、pH4.5、温度30℃、接种量10%的最佳发酵条件下,发酵终液酒精体积分数可达19.02%,远高于普通发酵(10%～15%)。并在最佳发酵条件下,对糖代谢情况进行初步研究。结果表明：在发酵过程中,锤度为30°BX时,酒精体积分数最大,且糖分完全利用,35°BX时,果糖无法被完全利用,40°BX时,葡萄糖和果糖都无法被完全利用;发酵液中糖分的渗透压与时间成负线性关系,且下降速率与初始糖锤度成线性负相关。     

Development of Hydrolyzed and Hydrolyzed-lsomerized Syrups from Cheese Whey Ultrafiltration Permeate and Their Utilization in Ice Cream

Hydrolyzed lactose syrup (HLS) was produced from cheese whey ultrafiltration permeate by treatment with immobilized β-galactosidase, deionization, and evaporation. The degree of hydrolysis was 97.2%. Hydrolyzed-isomerized lactose syrup (HILS) was produced from hydrolyzed, deionized ultrafiltration permeate by treatment with immobilized glucose isomerase, deionization and evaporation. The degree of isomerization was 34.8%. HLS and HILS were substituted for 25% or 50% of the sucrose (on a solids basis) in vanilla ice cream. The mix freezing time increased when HLS or HILS was substituted for sucrose at a level of 50%. There were no significant differences in melting rates (P < 0.05) and few differences in sensory quality.     

Mass production of D-psicose from d-fructose by a continuous bioreactor system using immobilized D-tagatose 3-epimerase

An improved process for the mass production of D-psicose from D-fructose was developed. A D-fructose solution (60%, pH 7.0) was passed at 45 degrees C through a column filled with immobilized D-tagatose 3-epimerase (D-TE) which was produced using recombinant Escherichia coli, and 25% of the substrate was converted to D-psicose. After epimerization, the substrate, D-fructose, was removed by treatment with baker's yeast. The supernatant was concentrated to a syrup by evaporation under vacuum and D-psicose was crystallized with ethanol. Approximately 20 kg of pure crystal D-psicose was obtained in 60 d.     

Effect of Oxygen, Carbon Dioxide, and Nitrogen on Maple Syrup Stored in Plastic Jugs

Six maple syrups were stored in the dark for 6 months in pigmented and unpigmented high-density polyethylene jugs at room temperature (72°F) in three gas environments-nitrogen, oxygen, and carbon dioxide. The syrup was analyzed for changes in flavor, color, and pH. A taste panel, tasting syrup from pigmented jugs only, detected flavor change in both the oxygen and carbon dioxide environments. There were statistically significant interactions for changes in both color and pH between gas and syrup treatments. The greatest darkening of color and decrease in pH were associated with the carbon dioxide. Jug pigmentation had no detectable effect on the syrup.     

Sucrose Degradation Under Model Processing Conditions

ABSTRACT: During raw and refined sugars processing, chemical changes occur that affect yield and end product color. Model sucrose solutions of 65 and 15 brix were treated with invert sugar levels of 0 to 4%, adjusted to pH 6 to 9, then processed 85 7deg;C for 0 to 6 h. Sucrose loss was correlated with changes in invert sugar concentration under acid conditions. Invert sugars concentrations were correlated with color development under alkaline conditions. At both 65 and 15 brix sucrose, and pH below 7.5, samples showed a 25% increase in invert sugars from acid hydrolysis. Sucrose loss was 1.6% with 3% invert sugar present. At pH 8.5 and higher, color increased in direct correlation with invert sugar concentrations.     

Probability of growth of the spoilage yeast Zygosaccharomyces bailii in a model fruit drink system

A quantitative method for the prediction of the probability of growth of the food spoilage yeast Zygosaccharomyces bailii in a model fruit-drink system is described. A factorially designed experiment, employing a microtitre-plate system was used to assess the effect on growth of culture pH and fructose concentration (°brix) as well as the weak-acid preservatives benzoic acid, sorbic acid and sulphur dioxide. Probability of growth was approximated to a logistic generalized linear model allowing a polynomial equation relating concentrations of sorbic acid, benzoic acid, sulphur dioxide, °brix and hydrogen ions to a function of the probability of growth to be produced.The resulting equation demonstrates a synergistic effect between ^obrix level and weak-acid concentration which is pH dependent. By quantifying this and other interactions as well as single effects the present model can be a useful tool not only to assess existing preservative systems but also during product formulation.