Rotating Disk-Assisted Cross-Flow Ultrafiltration of Sugar Beet Juice

Rotating disk module (RDM)-assisted cross-flow ultrafiltration of sugar beet juice, obtained by cold pulsed electric field-assisted pressing, was studied in full recycling and concentration modes. Results of trans-membrane pressure (TMP) stepping tests with 10- and 50-kDa membranes showed that filtration flux increased with rotation speed and TMP until 1000 rpm and 4 bar. A slight variation of filtration purity was observed for a rotation speed range of 0–2500 rpm. A TMP increase resulted in purity reduction due to the formation of thicker fouling layer. A full recycling test study with a 10-kDa membrane confirmed the influence of TMP and rotation speed on filtration flux. A rotation speed of 1000 rpm and a TMP of 4 bar were selected for sugar beet juice purification, by concentrating juice from 13 to 1 L. The results of concentration mode tests revealed that, with a 10-kDa membrane, the filtrate purity could reach 95.6 ± 0.5 %, which was comparable to the purity of sugar beet juice purified by conventional liming-carbonation method. The flux decline in cross-flow filtration was still important, justifying more effective anti-fouling technologies investigation.     

Dead end ultra-filtration of sugar beet juice expressed from cold electrically pre-treated slices: Effect of membrane polymer on fouling mechanism and permeate quality

Purification of raw sugar beet juice expressed at ambient temperature (20 °C) from pretreated sugar beet slices by pulsed electric field (E = 600 V·cm^− 1, t_PEF = 10 ms, T = 20 °C) was studied on the laboratory scale by dead-end ultrafiltration tests. Polyethersulfone (PES) and Regenerated Cellulose (RC) membranes with the same nominal molecular weight cut-off of 30 kDa were used. Experiments were carried out in unstirred and stirred (at rotation speed of 500 rpm) mode at constant trans-membrane pressure of 2 bar. The effects of the membrane polymer (Polyethersulfone and Regenerate Cellulose) on the filtration flux and the permeate quality were studied. In order to identify the fouling mechanism, the filtration kinetics was modeled using combined fouling models. Results showed that the filtration productivity (filtration flux) and selectivity (rejection ratio of impurities) depended on the membrane polymer. The juice filterability was better with Regenerated Cellulose (RC) membrane while the polyethersulfone (PES) membrane ensured a better retention of impurities (colorants, proteins and colloids), leading to a higher juice purity. Experimental and models data adjustment showed that combined models were preferable to investigate the fouling mechanism for both unstirred and stirred filtration. The desirable sugar purity (95–96%) of filtrate implies the potential application of a novel process (PEF treatment-cold pressing-ultrafiltration) for sugar industrial production.Industrial relevancePre-treatment by pulsed electric field PEF allowed cold or mild extraction of sucrose from sugar beet roots. The combination of PEF and ultra-filtration allowed high yield sucrose extraction and purification with less energy consumption. Membrane fouling analysis led to better filtration producibility. The obtained data can be useful for optimization of the sucrose production with high yield in industrial extraction processes.     

Purification of Purple Sweet Potato Extract by Dead-End Filtration and Investigation of Membrane Fouling Mechanism

Pulsed ultrasound-assisted extraction with water was carried out to extract valuable compounds from purple sweet potato (PSP). Quality properties and dead-end filtration of PSP extract were investigated. Solutes concentration in PSP extract were 118.60?±?2.83, 599.8?±?8.28, and 0.72?±?0.03 μg mL^?1 for total protein, total polyphenol, and total anthocyanin, respectively. Filtration with PES 50 kDa membrane-augmented polyphenol purity from 83.4 % in extract to 99.6 %. A protein removal coefficient of 99 % was achieved. Resistance in series model and Hermia’s model was applied to quantify filtration resistance and investigate fouling mechanism during filtration. Gel layer resistance was the most important for all three used membranes (PES 0.1 μm, PES 100 kDa, and PES 50 kDa). Fitting of experimental data by Hermia’s model revealed that the most suitable fouling mechanism varied, cake layer model for PES 0.1 μm and PES 100 kDa membrane and intermediate blocking model for PES 50 kDa membrane. For the purpose of more efficient polyphenol production, advanced filtration modules, such as cross-flow and rotating disk filtration module, are expected.     

菊芋资源的开发利用

根据国内外近期研究成果,简要介绍了菊芋的生长习性及菊芋块茎的主要成分,比较系统地介绍了菊芋资源的开发现状,其中包括菊芋粉、菊芋汁、菊糖、果糖和低聚果糖等主要菊芋制品的生产、功能性及其在食品工业中的应用。     

Chicory juice clarification by membrane filtration using rotating disk module

Clarification is the first step of inulin production from chicory juice, and membrane filtration as an alternative can greatly simplify this process, increase juice yield, improve product quality, and reduce the cost and waste volume. In this study, a rotating disk module (RDM) was used to investigate the clarification of chicory juice by four micro- and ultrafiltration membranes. Compared with dead end filtration, the RDM had a much higher permeate flux and product quality. High rotating speeds produced high permeate fluxes and reduced flux decline, because of the strong back transport of foulant from fouling layer to feed solution. At high rotating speeds of 1500–2000 rpm, the permeate flux increased with membrane pore size and transmembrane pressure (TMP), while at low rotating speeds (<1000 rpm), permeate flux was independent of membrane type and TMP due to a thick deposited fouling layer as a dominant filtration resistance, while carbohydrate transmission decreased at higher TMP because of denser cake layer as an additional selective membrane. The highest carbohydrate transmission (∼98%) and desirable permeate turbidity (2.4 NTU) was obtained at a TMP of 75 kPa and a rotating speed of 2000 rpm for FSM0.45PP membrane. With the RDM, the Volume Reduction Ratio (VRR) could reach 10 with a high permeate flux (106 L m⁻² h⁻¹) in the concentration test, and permeate was still rich in carbohydrate and well clarified. Chemical cleaning with 0.5% P3-ultrasil 10 detergent solution was able to recover 90% water flux of fouled membrane.     

Identification of Fouling Mechanism During Ultrafiltration of Stevia Extract

Stevioside is one of the naturally occurring sweetener, which can be widely applied in food, drinks, medicine, and daily chemicals. Membrane separation has potential application in clarification of stevioside from pretreated stevia extract by ultrafiltration. In the present study, namely 5-, 10-, 30-, and 100-kDa molecular weight cutoff membranes have been used. Quantification of membrane fouling during ultrafiltration is essential for improving the efficiency of such filtration systems. A systematic analysis was carried out to identify the prevailing mechanism of membrane fouling using a batch unstirred filtration cell. It was observed that the flux decline phenomenon was governed by cake filtration in almost all the membranes. For 100 kDa membrane, both internal pore blocking and cake filtration are equally important. Resistance in series analysis shows that the cake resistance is several orders of magnitude higher than the membrane resistance. The cake resistance is almost independent of transmembrane pressure drop, which indicates the incompressible nature of the cake. A response surface analysis was carried out to quantify the development of cake resistance with time during ultrafiltration of various membranes. Quality parameters show that the 30-kDa membrane is better suited for clarification purposes. Identification of the fouling mechanism would aid in the process of design and scaling up of such clarification setup in future.     

陶瓷膜处理乙醇发酵废水的工艺条件研究

发酵法生产乙醇的过程中产生大量废水,文中采用陶瓷膜处理乙醇发酵废水,考察了膜孔径、料液性质以及操作条件对过滤过程的影响。结果表明,陶瓷膜过滤乙醇发酵废水有较好的效果,化学需氧量(COD)去除率达80%,固体悬浮物(SS)截留率在99%以上。确定了孔径为200nm的膜管在pH值为8.0,错流速度为5m/s,温度为50℃,操作压力0.15MPa条件下操作,膜通量大于700L/(m2·h)。     

A simplified spectrophotometric method for the determination of inulin in Jerusalem artichoke (<Emphasis Type="Italic">Helianthus tuberosus</Emphasis> L.) tubers

A simple spectrophotometric method was developed for the analysis of inulin in Jerusalem artichoke tubers. The inulin was extracted from the artichoke tuber samples using accelerated solvent extraction method, before subsequent hydrolysis in acid condition. The hydrolysates were then analyzed for fructose using spectrophotometry. The spectrophotometric method is based on oxidation of fructose by periodate and evaluation of the remaining periodate by measuring the absorbance at 350 nm of the tri-iodide complex formed, upon addition of potassium iodide. The optimum conditions for the detection of fructose were 0.1 mmol L⁻¹ periodate and 1.5 mmol L⁻¹ potassium iodide at pH 6.0. The proposed method was validated for its analytical performance parameters including accuracy, precision, and recovery. The method was applied to the determination of inulin in ten varieties of Jerusalem artichoke grown in the northeastern part of Thailand. The inulin content in the samples was found to be in the range of 63–75.5% dry weight, and the degree of polymerization was in the range of 14–20. The inulin contents obtained from the proposed spectrophotometry were not significantly different (p = 0.05) from those obtained from high-performance anion-exchange chromatography coupled with pulsed amperometric detection. The results indicated that the present spectrophotometric method can be used as an alternative to chromatographic analysis for the determination of inulin in plant samples.     

Fundamental Understanding of Fouling Mechanisms During Microfiltration of Bitter Gourd (<Emphasis Type="Italic">Momordica charantia</Emphasis>) Extract and Their Dependence on Operating Conditions

Microfiltration of bitter gourd (Momordica charantia) extract using hollow fiber membrane module was carried out in the present study. To identify the dominant fouling mechanism, flux decline behavior was examined using Field model. At lower transmembrane pressure, pore blocking mechanism was found to be more important, while cake filtration was dominant at higher pressure. Higher cross flow rate reduced filtration constant indicating slower rate of membrane fouling. Additionally, surface and particle size analyses were undertaken to validate the findings of modeling. Scanning electron microscope analysis clearly showed prevalence of pore blocking mechanism at lower transmembrane pressure drop, whereas cake filtration was dominant fouling mechanism at higher pressure. Fourier transform infrared spectroscopy analysis supported the role of cake layer as a secondary membrane retaining some amount of polyphenols. Analysis of flux decline ratio also confirmed that for transmembrane pressure of 104 kPa and beyond, cake layer became compact, and hence, increase in cross flow rate was unable to influence the improvement of permeate flux. The current study provides an insight into the fouling mechanism involved in scaling up of clarification of bitter gourd extract for successful processing of this medicinal herb.     

牛蒡菊糖和菊芋菊糖对酒精诱导大鼠慢性氧化损伤的防治作用

[目的：研究酒精对小鼠肾、脑、心脏及睾丸中GSH、MDA 的影响,并探讨牛蒡菊糖在保护脏器氧化损伤方面的作用并与菊芋菊糖进行比较研究。方法：雄性成年小鼠随机分为6 组(牛蒡菊糖低、中、高3 个剂量组,菊芋菊糖组,酒精模型组和空白对照组),共灌胃20d。实验结束后,分别取脑、肾、心脏和睾丸,制成10% 组织匀浆,离心,取上清液测定丙二醛(MDA)、还原性谷胱甘肽(GSH)含量。结果：1)肾脏：小鼠灌胃酒精后,GSH 含量与对照组比较差异不显著(P ＞ 0.05),灌胃酒精和不同剂量牛蒡菊糖以及菊芋菊糖后GSH 含量显著低于酒精组(P ＜ 0.05,P ＜ 0.01);小鼠灌胃酒精后MDA 含量与对照组比较显著升高(P ＜ 0.01),灌胃酒精和中高剂量牛蒡菊糖后MDA含量显著低于酒精组(P ＜ 0.05),但灌胃酒精和菊芋菊糖后MDA含量与酒精组比较差异不显著(P ＞ 0.05)。2)脑：小鼠灌胃酒精后GSH 含量与对照组比较显著降低(P ＜ 0.01),灌胃酒精和中高剂量牛蒡菊糖后GSH 含量显著高于酒精组(P ＜ 0.01),但灌胃酒精和菊糖后GSH 含量与酒精组比较无显著性差异(P ＞ 0.05);小鼠灌胃酒精后MDA 含量与对照组比较显著升高(P ＜ 0.01),灌胃酒精和高剂量牛蒡菊糖以及菊芋菊糖后MDA 含量与酒精组比较显著降低(P ＜ 0.01)。3)心脏：小鼠灌胃酒精后GSH 含量与对照组比较略有降低但无显著性差异(P ＞ 0.05),灌胃酒精和高剂量牛蒡菊糖后GSH 含量显著高于酒精组(P ＜ 0.01),但灌胃酒精和菊芋菊糖后GSH 含量与酒精组比较无显著性差异(P ＞ 0.05);小鼠灌胃酒精后MDA 含量与对照组比较无显著差异(P ＞ 0.05),灌胃酒精和高剂量牛蒡菊糖以及菊芋菊糖后MDA 含量与酒精组比较也无显著差异(P ＞ 0.05)。4)睾丸：小鼠灌胃酒精后GSH含量与对照组比较无显著性差异(P＞ 0.05),灌胃酒精和牛蒡菊糖以及菊芋菊糖后GSH含量与酒精组比较变化也无显著性差异(P ＞ 0.05);小鼠灌胃酒精后MDA 含量与对照组比较略有升高但无显著差异(P ＞ 0.05),灌胃酒精和中高剂量牛蒡菊糖后MDA 含量与酒精组比较显著降低(P ＜ 0.05),但灌胃酒精和菊芋菊糖后MDA 含量与酒精组比较无显著性差异(P ＞ 0.05)。结论：在本实验条件下,酒精能较显著地引起小鼠肾脏和脑组织的氧化损伤但对心脏和睾丸的氧化损伤较小。牛蒡菊糖和菊芋菊糖对上述器官的氧化损伤具有一定的保护作用。     

超滤技术分离花生抗氧化肽及其性能研究

采用超滤技术分离花生抗氧化肽,研究超滤操作压力、温度、pH 值和滤液浓度对膜通量的影响,结果表明,滤液浓度2%,压力0.08MPa,温度25℃和时间20min 条件下,膜通量相对较高为45.18ml/m2·min,分子量3kD 以下的花生肽抗氧化活性较高。利用大豆油研究花生抗氧化肽的活性,当添加0.10% 3kD 花生抗氧化活性肽到大豆油中,存放7d 其POV 值为9.15meq/kg,抗氧化活性较好。     

菊粉酶的研究进展

菊粉酶是一类能水解β-2,1-D-果聚糖果糖苷键的水解酶,属于糖苷水解酶32家族。菊粉酶是菊芋生物炼制中的关键酶,它能将菊芋一步水解,获得高纯度的果糖浆,生产燃料乙醇、燃料丁醇、单细胞油脂、生物柴油、甘露醇和乳酸等其它工业产品,在食品、医药及生物能源等领域有着巨大的应用价值。该文介绍了菊粉的分子结构及来源,概述了菊粉酶的分类、来源、克隆表达、三维结构及应用,并对菊粉酶的未来发展方向进行了展望,旨在提高人们对菊粉酶的认识,推动菊芋生物炼制的研究。     

Extraction and Enzymatic Hydrolysis of Inulin from Jerusalem artichoke and their Effects on Textural and Sensorial Characteristics of Yogurt

Inulin has become an attractive ingredient in the food industry because of its nutritional and functional characteristics. Extraction of inulin from Jerusalem artichoke and the effects of its enzymatic hydrolyzate on the textural and sensorial characteristics of yogurt were investigated. The extraction yield (98%) of inulin was obtained with dry Jerusalem artichoke powder. The thin-layer chromatography and the ion chromatogram analysis of the enzymatic hydrolyzate revealed that inulinase hydrolyzed inulin into fructooligosaccharides with degrees of polymerization from 2 to 10. Utilization of inulin and hydrolyzate in yogurts improved their textural properties. Sensorial evaluation of yogurts showed that yogurts with inulin or its hydrolyzate had a better body and smoother texture than yogurts with sucrose only. The findings of this study suggest that inulin or its hydrolyzate can partially replace sucrose in formulations in the food industry.     

乳酸菌发酵菊芋汁及其风味的研究

对不同品种和产地的菊芋主要成分进行了测定,并利用乳酸菌对菊芋汁进行发酵,研究了不同乳酸菌在菊芋汁中的生长规律、低温存活性及发酵菊芋汁中主要风味物质。结果表明,4种乳酸菌在菊芋汁中均生长良好,最高活菌数可达到109CFU/mL;菊芋汁经乳酸菌发酵后具有良好风味,其风味的差异与发酵菌种有关;发酵菊芋汁中乳酸菌在4℃低温贮藏过程中具有较好的低温存活性,4周后活菌数保持在108CFU/mL。菊芋汁适用于开发成新的功能性乳酸菌饮料。     

生物型洋姜饮料的研制

利用廉价的洋姜为原料,经过脱皮、护色、切片、过滤、生物水解、调配等工艺,研制出一种色泽、风味和口感都很好的洋姜饮料,从而为洋姜的精深加工提供一定的思路和方法。     

Enzymatic Hydrolysis of Inulin — An Alternative Way to Fructose Production

In the seventies large amounts of fructose have been produced from starch by isomerization of glucose. An alternative source of fructose is inulin, present as energy reserve in plants, e. g. from the composite family such as chicory and Jerusalem artichoke. To produce fructose from inulin a hydrolysis step is necessary. This can be performed by acids, but enzyme hydrolysis is preferable because of lower byproduct formation. An enzyme specially suited for industrial application is described. Full hydrolysis of inulin more than 98% (fructose and glucose) can be achieved at 60–65°C using economical dosages of enzyme. The reasons for the special efficiency of the enzyme are touched upon.     

翘鳞伞胞外多糖无机陶瓷膜分离提取工艺优化研究

【研究目的】采用无机陶瓷膜分离提取翘鳞伞胞外多糖,考察不同孔径的膜对膜过程妁影响,优化膜通量影响因素,获得超滤膜分离最佳工艺条件;【方法】以微滤处理后的翘鳞伞发酵液为研究对象,测定了5种不同孔径超滤膜的膜通量以及多糖截留率,采用L9（3^4）正交实验优化了超滤工艺条件;【结果】在5种陶瓷超滤膜中,截留分子量为50kDa的超滤膜最适合于翘鳞伞胞外多糖发酵液分离浓缩,当压力在0．1～0．4MPa,温度在20～40℃时,压力和温度的提高均有利于超滤膜通量的增大,而料液质量浓度的增加对多糖截留率影响较小．【结论】选择50kDa的超滤膜在压力0．3MPa、温度40℃、料液质量浓度0．8g/L的条件下,其膜通量以及多糖截留率最佳。     

Scale‐up batch fermentation of bioethanol production from the dry powder of Jerusalem artichoke (Helianthus tuberosus L.) tubers by recombinant Saccharomyces cerevisiae

This study is a first exploration of industrial bioethanol production from the dry powder of Jerusalem artichoke (Helianthus tuberosus L.) tubers by recombinant S. cerevisiae 6525. Scale‐up fermentation of bioethanol production from the dry powder of Jerusalem artichoke tubers by recombinant Saccharomyces cerevisiae 6525 was carried out at the scale of 50 and 500 L agitating fermentors. For the 50 L fermentor, 85.67 g/L of ethanol was obtained within 72 h of fermentation, and the ethanol yield was 90.1%. For the 500 L fermentor, the highest ethanol concentration of 77.00 g/L was achieved at 84 h, and the ethanol yield was 81.01%. These results indicated that a relatively high yield of ethanol could also be obtained from a scaled‐up fermentation of Jerusalem artichoke powder. Thus, it may be feasible to use a Jerusalem artichoke tuber feedstock to carry out ethanol fermentations using the recombinant S. cerevisiae 6525 for industrial production. Copyright © 2016 The Institute of Brewing & Distilling     

Deacidification of Coconut Oil by Membrane Filtration

Ultrafiltration (UF) of coconut oil was carried out using a Millipore membrane cell at different pressures (0.1–0.4 MPa) and with different molecular weight cutoff membranes, that is,YM-1 (1 kDa), YM-3 (3 kDa), YM-10 (10 kDa), YM-30 (30 kDa), and PLTK-30 (30 kDa). Reduction of free fatty acids (FFAs) was 93.6%, 92.7%, 83.5%, 82.6%, and 81.6% with ethanol, methanol, acetone, n-propanol, and isopropyl alcohol, respectively, in three-stage filtration. The effects of temperature and applied pressure on the permeate flux and oil rejection were also studied with membranes using multistage filtration. As pressure increased from 0.1 to 0.4 MPa, the permeate flux and oil rejection increased linearly. A significant reduction of FFA was observed, which is in proportional with the amount of solvent in the feed used. The oil loss was less at lower temperature (25 °C) and pressure (0.2 MPa). Using PLTK 30 membrane with three-stage filtration, reduction of FFA was achieved up to 93% and 94% with methanol and ethanol solvents, respectively.     

陶瓷膜和有机膜超滤处理荔枝汁和膜垢分析及荔枝汁品质研究

应用陶瓷膜和有机膜对荔枝汁进行澄清实验,并进行采用总循环模式(TRM)研究跨膜压力(TMP)和循环流量(Qf)对膜通量(Qp)的影响,确定其各自的最优水平;采用批处理模式(TBM)研究这两个参数最优水平的组合工艺。澄清工艺中：无机陶瓷膜效果优于有机聚醚砜膜,最佳工艺条件为陶瓷膜组件、TMP 0.3MPa、Qf 40L/min。研究在TBM下,膜垢的形成原因,对微分方程--＝k(J－Jlim)J2－n进行拟合,拟合R2为无机膜0.8812和0.8478;有机膜为0.9048,并分析膜垢的形成的模式：有机膜的膜垢主要是层垢(n＝0),无机膜的膜垢形成主要是层垢和部分并在膜垢的综合情况(n＝0,n＝1)。并研究TBM模式下,总糖、总果胶、总蛋白、抗氧化活性等影响果汁品质的物质的动态过程,结果表明：在P＜0.05,无机膜在品质的保持比如总糖、抗氧化活性、总酚的截留滤等方面强于有机膜,其余的品质无显著差异。