Maltose Concentration by Ultrafiltration

[Objective] The aim was to study on effect of maltose concentration by ultrafiltration.[Method] 40% and 15% maltose syrups were concentrated using ultrafiltrati...     

Passion Fruit Juice Concentration by Ultrafiltration and Evaporation

Passion fruit juice was pretreated with pectinase, centrifugation, and pasteurization. The resulting juice was processed by Ultrafiltration (UF) to 20°Brix. The UF permeate was concentrated by evaporation to 70°Brix and combined with the UF retentate to form the final concentrated product at 40°Brix. The pretreatments caused approximately 20% flavor losses, but accomplished more than 50% flux increases. The UF recovered many important flavor constituents, and improved the rate of evaporation. The final concentrated product contained more than 30% of juice flavor. Results of sensory evaluation indicated that flavor of the reconstituted juice was inferior to fresh juice, but the two juices were not significantly different in overall acceptance.     

紫苏叶花色苷抗氧化作用的研究

目的:研究紫苏叶花色苷的抗氧化作用。方法:以TBHQ、VC、紫苏叶水提物作对照,通过铁离子还原/抗氧化能力测定,清除·DPPH自由基和ABTS+自由基试验以及抗氧化能力指数的测定,研究紫苏叶花色苷的抗氧化活性。结果:紫苏叶花色苷具有较强的铁离子还原/抗氧化能力,对·DPPH自由基和ABTS+自由基均有良好的清除作用,能够通过抑制氢转移反应过程终止自由基链式反应。结论:紫苏叶花色苷具有良好的抗氧化能力,其抗氧化性随浓度的增大而增强。紫苏叶花色苷有望作为天然抗氧化剂及功能性食品得到开发利用。     

草浆废液的超滤浓缩

通过草浆废液的超滤浓缩实验，测定了荻苇亚硫酸氢镁红液、麦草Ｓｏｄａ－ＡＱ黑液和稻草硫酸盐黑液超滤浓缩的固形物上限浓度分别为２６．１２％、２７．３３％和３１．５２％。在废液浓度较低时，由于水通量大，超滤浓缩能耗低的优势尤为明显。超滤用于废液的预浓缩具有显著的经济效益。     

Purification and Concentration of Betalaines by Ultrafiltration and Reverse Osmosis

Beet juices prepared by solid-liquid extractions were processed by ultrafiltration (UF) and reverse osmosis (RO) to 30°Brix at 20°C. De Danske Sukkerfabrikker (DDS) UF/RO Lab Module-20 plate-and-frame system was used having a 0.72-m² effective membrane area and pressures from 50-40 bar. After prefiltering, pectinase treated juices were sequentially processed through 20,000 and 6,000 (UF) molecular weight (MW) cut-off membranes. The UF purified products were then concentrated by RO processes on several types of cellulose acetate (CA) membranes, one with a 500 MW cut-off and 70% NaCl permeability provided colorants that were separated from a majority of soluble solids. Addition of invertase to pectinase-treated juices decreased flux but yielded a three-fold increase in betalaine concentration on a dry weight basis. Betalaine concentration by UF and RO processes also halved nitrate level and greatly reduced flavor.     

Ultrafiltration/Reverse Osmosis Concentration of Lobster Extract

A membrane concentration system consisting of tubular polysulphone ultrafiltration (UF) and polyamide reverse osmosis (RO) was evaluated for concentrating key water soluble flavor compounds from lobster extracts. Major flavor-giving compounds in the extract were glutamic acid, glycine, arginine, uridine 5′-monophosphate (UMP), succninic acid and glucose. Factors affecting performance of the UF/RO systems, such as flow rate, feed solid level, temperature and pressure, on permeate flux and solids rejection were measured. The optimum UF conditions were 1.5% feed solid level, 15 L/min feed flow rate, 50°C feed temperature and 1 MPa log mean transmembrane pressure. The RO system retained all dissolved flavor components and its ideal operating conditions were 40°C, 2.8 MPa log mean transmembrane pressure and a flow rate of 15 L/min.     

超滤法浓缩分离免疫初乳中的抗体

收集经大肠杆菌、沙门氏菌混合疫苗免疫处理的乳牛产后７天之内初乳,经去脂、去酪蛋白后所得免疫初乳乳清,用中空纤维超滤器（分子截留为１００ｋｕ（１００ｋｄ）进行浓缩分离,浓缩４．５～７倍、ＩｇＧ收率在９０％以上。为了制得高纯度ＩｇＧ分离物,可和３５％饱和度的硫胺进行盐析,然后再进行超滤脱盐、浓缩、制得的ＩｇＧ浓缩物纯度达８０％以上,这一工艺适合工业化生产。     

乳酸菌发酵液中胞外多糖的超滤浓缩技术研究

采用了内压式中空纤维膜超滤装置对乳酸乳球菌乳亚种发酵液中胞外多糖进行超滤浓缩分离。研究结果表明:在操作压力0.08MPa,操作温度25℃的条件下,用分子量为50ku的膜超滤经离心除菌的发酵液,发酵液的体积浓缩了5倍多,而胞外多糖的含量从949.54mg/L上升到4790mg/L。     

Concentration of Skim Milk by a Cascade Comprised of Ultrafiltration and Nanofiltration: Investigation of the Nanofiltration of Skim Milk Ultrafiltration Permeate

In order to reach a high volume reduction ratio (VRR) prior to drying of skim milk, a membrane cascade comprising of an ultrafiltration (UF) coupled with a nanofiltration (NF) can be applied. The present study investigated the impact of processing (filtration temperature, transmembrane pressure (TMP)) and product (feed pH) parameters on the NF of skim milk UF permeate. It could be shown that a low filtration temperature of 10 °C is more advantageous in terms of flux stability and rejection of the solute fraction as compared to higher filtration temperatures up to 45 °C. The solution pH did not affect permeate flux and lactose retention. However, in order to avoid calcium losses, it is more favorable to conduct the concentration at a pH of 6.8 instead of at a lower pH of 5. The application of a higher TMP (up to 4 MPa) enhances permeate flux and VRR as well as solute rejection during concentration of UF permeate. It was also shown that the retention of solutes decreases towards the end of the concentration process. As a consequence, the achievement of high final VRR must be weighed against increased product losses at the end.     

硼改性微粒硅溶胶的超滤浓缩及稳定性

选用超滤法浓缩硼改性微粒硅溶胶,在室温、操作压力3.5 kPa的条件下、选用截留相对分子质量为10000的醋酸纤维素超滤膜浓缩硼改性微粒硅溶胶,其截留率大于93%,可将硼改性微粒硅溶胶浓缩到15%~16%,并且硼改性微粒硅溶胶不易变性。实验采用阴离子及非离子表面活性剂来提高高浓度硅溶胶的稳定性,结果表明,用量0.01%的羧甲基纤维素分散效果最佳,对硼改性微粒硅溶胶的性能几乎没有影响,有利于实现商品化。     

异丙醇浸出紫苏籽低温压榨饼的研究

采用异丙醇作溶剂对紫苏籽低温压榨饼进行浸出。改变浸出次数,料溶比,溶剂浓度3个因素,在温度78℃,每次15 min条件下进行浸出,对浸出粕中的残油率、蛋白质、单宁及植酸含量进行检测,得出异丙醇浸出紫苏籽低温压榨饼的最佳工艺条件为:浸出次数5次,料溶比1∶1.5(W/V),溶剂浓度87.7%。最终得到紫苏浸出粕的残油率为0.61%,蛋白质含量51.5%(N×6.25,干基),单宁含量1.7%,植酸含量2.81%。     

超滤技术在生产精制糖浆中的应用

研究了不同操作条件下对不锈钢膜超滤原糖浆的影响,通过加入高离子澄清剂Ｇ４０９提高糖浆的脱色与除浊效率,并改良其超滤性能。与传统工艺相比,这种絮凝与膜滤相结合的技术能显著提高脱色与除浊效率。不锈钢膜具有耐酸碱,耐高温,抗脆裂,易清洗的优点。     

超滤法生产大豆浓缩蛋白

采用商业聚砜平板膜生产大豆浓缩蛋白。脱脂豆粕和水按一定比例混合 ,pH8 0室温下搅拌 40min ,离心 ,上清液经超滤、冷冻干燥 ,得到大豆浓缩蛋白。蛋白质含量由 5 2 % (干基 )提高到 72 % (干基 )。蛋白质的回收率达到 90 %以上。根据浓差极化模型得到间歇式超滤浓缩蛋白质时的理论极限蛋白质含量。     

Anthocyanins of Asparagus

SUMMARY— Four anthocyanin pigments were isolated from asparagus spears, Asparagus officinalis L., and identified by chromatographic, spectral, and chemical properties. The major pigment was a linear triglycoside, cyanidin-3-rhamnosylgluco-sylglucoside, followed by cyanidin-3-rhamnosylglucoside. The peonidin analogues of the above pigments were also present in minor quantities.     

超滤法提取大豆低聚糖前处理的研究

大豆乳清是大豆蛋白生产厂的副产品 ,其中含有大豆低聚糖。大豆低聚糖主要包括蔗糖、棉子糖和水苏糖 ,棉子糖和水苏糖具有促进双歧杆菌增殖的作用。本文对采用超滤技术提取大豆乳清中的大豆低聚糖进行了系统的研究 ,研究发现 ,未经前处理的大豆乳清直接进行超滤时 ,大豆低聚糖的截留率高 ,超滤速度慢 ,因此 ,必须对大豆乳清进行前处理。通过正交实验确定了最佳工艺方案和工艺参数 ,最佳工艺参数为pH7,CaCl2 加入量为固形物的 2 0 % ,温度 10 0℃ ,时间 15min。对最佳前处理条件下得到的溶液进行超滤后 ,得到了较高纯度的大豆低聚糖溶液     

Isolation of Casein by Ultrafiltration and Cryodestabilization

Casein was isolated from skim milk by ultrafiltration, storage of the retentate at -8°C for l-4 wk, and centrifuging of thawed samples at 5,000 ×g for 10 min. The extent of cryodestabilization of casein was dependent on the extent of ultrafiltration and storage time at -8°C. Ultrafiltration to a 4× or 6× volume concentration (VCR) ratio resulted in greater than 95% recovery of casein. Casein thus precipitated could be washed with water at 0°C without any significant loss of casein. Removal of lactose caused accelerated casein cryodestabilization in ultrafiltered samples as compared to control samples. Casein precipitated by this method is dispersible in water, whereas acid precipitated casein is not.     

大孔树脂纯化喀什小檗花色苷

研究XAD-7HP大孔树脂分离纯化喀什小檗花色苷的纯化工艺条件。通过树脂筛选和单因素实验确定适宜工艺参数:吸附时间是4h,体积分数60%乙醇溶液为洗脱液,解析时间100min,上样液pH值2.0,吸附温度为30℃,上样质量浓度为750mg/L,洗脱流速为1.0mL/min,。该工艺生产的花色苷产品为紫黑色粉末,色价和花色苷含量比纯化前分别提高了2.21倍和3.15倍。     

紫苏啤酒的研制

紫苏是食药两用植物,富含18种氨基酸、矿物质及黄酮类物质。研究了在啤酒酿造过程中添加紫苏汁的工艺流程,通过正交试验和感官评定的方法得出最佳工艺为:在主发酵前添加2％的紫苏汁, 发酵17天。实验结果表明,酿出的啤酒具有突出的紫苏香气,口味纯正爽口,适宜饮用。