浅析造纸行业消泡剂

消泡剂是造纸常用的一种添加剂,本文从泡沫的产生及消泡机理,常用消泡剂、消泡剂使用中需要注意的问题及消泡剂发展趋势几个方面对消泡剂进行了浅析。     

一种发酵用消泡剂的合成与效能

以蓖麻油与聚甘油合成了一种用于发酵过程的消泡剂，实验证明：聚甘油：蓖麻油＝1：2，在混合碱的催化下，在200℃恒温3．5h后，冷却，所得产物对发酵液的消、抑泡有良好的作用。     

制糖过程中泡沫的形成和消泡剂的消泡机理

综述制糖过程中的起泡成分、泡沫形成的条件及泡沫稳定存在的因素。消泡剂的进入系和匍展系数以及憎水颗粒的去润湿 作用，论述了消泡机理。     

消泡剂在造纸工业中的消泡机理及应用

文章就泡沫对制浆造纸的影响和危害进行了论述;介绍了除气消泡剂的类型、组成、应用方法以及产生的效果;对除气消泡剂的消泡机理进行了阐述分析;使用除气消泡剂已经成为制浆造纸企业控制泡沫的有效措施。值得注意的是,应根据应用目的而选择不同类型的除气消泡剂;两种不同类型的除气消泡剂互相配合使用比单一使用一种类型的除气消泡剂效果来的更理想些。     

乳液型有机硅消泡剂的研制

介绍了乳液型有机硅消泡剂的生产方法 ,并对各影响因素进行了详细的讨论     

消泡剂的复合及其消泡机理探讨

综述了泡沫的形成条件及构成泡沫稳定存在的因素：液膜弹性、表面粘度、溶液粘度、电双层斥力和熵双层斥力、气泡间气体的扩散；从消炮剂的进入系数和铺展系数以及憎水颗粒的去润湿作用，论述了消泡机理，阐述了复合消泡剂的概念及应用。     

糖用N型消泡剂使用特性的分析

本文研究了以N型消泡剂为代表的糖用消泡剂在蔗糖溶液中的添加量与消泡抑泡效果的关系,并以消泡时间和抑泡时间为衡量指标,将其与红油粉、蔗糖酯消泡剂和F型消泡剂的消泡效果相比较,最后通过表面张力的测量初步探讨消泡机理。研究结果表明：N型消泡剂浓度越高,消泡抑泡的效果越强,当糖浆中消泡剂的添加量达30ppm时便可取得满意的消泡抑泡效果;在相同用量浓度下,这几种消泡剂的应用效果也不一样,比较试验显示N型消泡剂和F型消泡剂具有优于红油粉的使用效果。此外,本文还初步考察了消泡效果与糖液表面张力的关系,发现应用效果好的消泡剂,会较大幅度地降低糖液的表面张力。     

BREOX FCC P18泡沫控制精制液与聚醚型和有机硅型消泡剂的对比

主要介绍了BREOX FCC P18泡沫控制精制液的作用原理,以及与我公司现用Z—01(聚醚型)和Z-02(有机硅消泡剂)在消泡速度与抑泡性能方面的比较     

聚硅氧烷消泡剂的研制及在糖业中的应用

聚硅氧烷消泡剂是一种广泛应用于医药，食品，日用化工，纺织，造纸行业的广谱消泡剂，用聚硅氧烷为主要原料，加入少量的消泡增效剂，选择适当的乳化体系及工艺制成，本文介绍了一种适用于制糖工业的高效环保型聚硅氧烷消泡剂（F型消泡剂）的制作方法及其应用。     

消泡剂在水基油墨中的应用与研究

介绍了油墨中气泡产生的原因、破坏机理及消泡剂的功用和种类。以水基油墨为例,论述了消泡剂在液体油墨中的消泡原理、消泡效果的检测以及消泡剂使用过量的弊端,并比较了实际应用中消泡剂种类的选择和最佳添加量。     

低乳糖中老年奶粉的研究

对低乳糖中老年奶粉进行了研究,通过实验得出配方（以总量100g计）：蛋白质为大豆分离蛋白2%,乳清浓缩蛋白4%,全乳蛋白质14%;脂肪的添加量为大豆油3.6%,菜籽油4.4%;以及各种营养素的强化量：VA1500～3000IU,VC60～80mg,VE15～20IU,VD400～500IU,VB1750～1000μg,VB2850～1000μg,烟酸700～1000μg,叶酸250～600μg,乳酸锌3～6mg,硫酸亚铁6～10mg,采用酶活力2000NLU/L的乳糖酶,添加量为0.2%,水解时间为4h,乳糖水解率达到90%以上。     

Recovery of lactose from simulated delactosed whey permeate by a low-temperature crystallization process

Delactosed whey permeate is the mother liquor/by-product of lactose manufacture, but it still contains around 20 wt% lactose. The high mineral content, stickiness, and hygroscopic behavior prevent further recovery of lactose in the manufacturing process. Therefore, its use is currently limited to low-value applications such as cattle feed, and more often it is seen as waste. This study investigates a new separation technique operating at sub-zero conditions. At low temperature, precipitation of calcium phosphate is expected to be reduced and the lower solubility at sub-zero temperature makes it possible to recover a large portion of the lactose. We found that lactose could be crystallized at sub-zero conditions. The crystals had a tomahawk morphology and an average size of 23 and 31 µm. In the first 24 h, the amount of calcium phosphate precipitated was limited, whereas the lactose concentration was already close to saturation. The overall rate of crystallization was increased compared with the crystals recovered from a pure lactose solution. Mutarotation was rate limiting in the pure system but it did not limit the crystallization of lactose from delactosed whey permeate. This resulted in faster crystallization; after 24 h the yield was 85%.     

Evaluating the crystallization of lactose at different cooling rates from milk and whey permeates in terms of crystal yield and purity

The cooling rate of supersaturated lactose solution is one of the important parameters determining the yield and size distribution of lactose crystals. The influence of increasing cooling rate on lactose crystallization and quality of lactose crystals was evaluated in concentrated solutions prepared from deproteinized whey powder (DPW) and milk permeate powder (MPP). Concentrated permeates (DPW and MPP) with 60% (wt/wt) total solids were prepared by reconstituting permeate powders in water at 80°C for 2 h for lactose dissolution. Three cooling rates, 0.04°C/min (slow), 0.06°C/min (medium), and 0.08°C/min (fast) were studied in duplicate. A common rapid cooling step (80 to 60°C at 0.5°C/min) followed by slow, medium, and fast cooling rates were applied as per the experimental design from 60 to 20°C. After crystallization, the crystal slurry was centrifuged, washed with cold water, and dried. The dried lactose crystals were weighed to calculate the lactose yield. Final mean particle chord lengths were measured at the end of crystallization using focused beam reflectance measurement for slow, medium, and fast cooling rates, and observed to be not significantly different for DPW (27–33 µm) and MPP (31–34 µm) concentrates. Similarly, the lactose yield for slow, medium, and fast cooling rates in the DPW and MPP concentrates were in the range of 71 to 73% and 76 to 81%, respectively, and no significant difference between the 3 cooling rates was found. Qualitative analysis of dried lactose crystals exhibited no noticeable differences in the crystal purity with increasing cooling rate. This study evaluated the possibility of reducing the crystallization times by 8 h compared with current industrial practice without compromising the crystal yield and quality.     

Short communication: Conversion of lactose and whey into lactic acid by engineered yeast

Lactose is often considered an unwanted and wasted byproduct, particularly lactose trapped in acid whey from yogurt production. But using specialized microbial fermentation, the surplus wasted acid whey could be converted into value-added chemicals. The baker’s yeast Saccharomyces cerevisiae, which is commonly used for industrial fermentation, cannot natively ferment lactose. The present study describes how an engineered S. cerevisiae yeast was constructed to produce lactic acid from purified lactose, whey, or dairy milk. Lactic acid is an excellent proof-of-concept chemical to produce from lactose, because lactic acid has many food, pharmaceutical, and industrial uses, and over 250,000 t are produced for industrial use annually. To ferment the milk sugar lactose, a cellodextrin transporter (CDT-1, which also transports lactose) and a β-glucosidase (GH1-1, which also acts as a β-galactosidase) from Neurospora crassa were expressed in a S. cerevisiae strain. A heterologous lactate dehydrogenase (encoded by ldhA) from the fungus Rhizopus oryzae was integrated into the CDT-1/GH1-1–expressing strain of S. cerevisiae. As a result, the engineered strain was able to produce lactic acid from purified lactose, whey, and store-bought milk. A lactic acid yield of 0.358 g/g of lactose was achieved from whey fermentation, providing an initial proof of concept for the production of value-added chemicals from excess industrial whey using engineered yeast.     

液相色谱法测定乳粉中乳糖方法优化

目的研究并优化GB 5413.5-2010《食品安全国家标准婴幼儿食品和乳品中乳糖、蔗糖的测定》样品制备步骤,解决婴幼儿配方乳粉中乳糖检测结果偏低的现象,保证乳糖检测的准确性。方法在样品溶液制备过程中,采取30 m L水溶解乳粉,并向容量瓶中加入1 m L 3%的乙酸水溶液协助蛋白沉淀,进而降低乙腈在样品溶液中的利用比例,保证样品制备过程中乳糖的充分溶解,最终通过液相色谱测定。结果同一份样品经不同的样品制备方式,于相同的色谱条件下检测,依据本法制得样品测定结果比遵循国标条件制得样品的结果高出7%,并且结果平行性良好。结论通过方法学研究,证实该方法具有适用性、重复性、准确度以及线性范围良好的特点,并且操作简便,适用于婴幼儿配方乳粉中乳糖的检测。     

Nanofiltration Concentration Effect on the Efficacy of Lactose Crystallization

Application of nanofiltration membranes to processing sweet whey and skim milk ultrafiltration permeate increased lactose crystal yield by about 10 and 8 %, respectively, at a concentration factor of 3.0. These increases were attributed to depletion of minerals, especially monovalent cations such as sodium and potassium, by the partial demineralization effect of the nanofiltration membrane. These membranes may be incorporated into current industrial processes for producing lactose from whey and milk permeates.     

肽类生物表面活性剂中消泡剂的分离研究

本研究首次建立硅胶柱层析两步法以去除抗菌脂肽粗品中所含有的大豆油消泡剂成分,实验中采用高效液相色谱（HPLC）检测抗菌脂肽的含量,薄层色谱-可见光分光光度法定量分析消泡剂中甘油三酯含量,TLC法筛选大豆油的洗脱流动相。研究结果表明:使用200³00目的硅胶作为层析材料,硅胶的总负载量为12.5mg/g时,采取混合液（石油醚∶乙酸乙酯∶乙酸=20∶2∶1,体积比）为流动相,以1m L/min流速进行洗脱,可将97.97%的大豆油成分去除;第二阶段采用流动相为100%的乙醇以1m L/min流速进行洗脱可将抗菌脂肽解吸,抗菌脂肽的总回收率达到91.52%,纯度从34.07%提高到93.12%。本研究为肽类生物表面活性剂工业化生产和应用提供实验依据。      

一种新型乳清碳酸饮料的制作工艺

介绍了一种将脱盐乳清粉配制成10%的水溶液,用β-半乳糖苷酶酶解降低其乳糖含量,经两组串联超滤装置处理得到澄清的饮料原液,最后调配加工成澄清型低乳糖碳酸饮料的制作工艺。结果表明,用以上处理方法可制得具有奶香风味、口感清爽并可供长期保存的乳清碳酸饮料。     

乳粉中乳糖数字图像检测方法的研究

基于样品液色度值与乳粉中乳糖含量在一定范围内具有良好的线性关系,提出了一种乳粉中乳糖的数字图像检测方法。利用该方法进行了样品的测定,与SN/T0871-2000方法相比没有显著差异。通过精密度和回收率实验表明:该方法具有良好的重复性和准确性。     

低乳糖酸奶的研制

研究了低乳糖酸奶产品的配方组成及其生产工艺条件等。结果表明，该产品除具备有普通酸奶的营养丰富全面、口味酸甜爽口纯正以及凝固性能良好和无褐变等特点外，其乳糖的水解率高达70％以上，可以有效的预防人体乳糖不耐症的发生。