Ultrafiltration of Banana (Musa acuminata) Juice Using Hollow Fibers for Enhanced Shelf Life

Banana juice was clarified by cross flow ultrafiltration using a hollow fiber module under total recycle mode. Three surface-modified polysulfone-based membrane cartridges with molecular weight cut-offs 10, 27, and 44 kDa were used to identify the most suitable membrane. The effects of operating conditions—namely, transmembrane pressure drop and cross flow rate on the permeate flux and permeate quality, have been investigated. The quality of the clarified juice was evaluated in terms of viscosity, clarity, color, alcohol insoluble solids, total soluble sugar, pH, protein, and polyphenol content. The results showed that the membrane of molecular weight cut-off 27 kDa was suitable. The permeate flux depended strongly on the transmembrane pressure drop, but its variation on cross flow rate was insignificant. The clarified juice had high clarity and no pectineous materials (in terms of alcohol insoluble solids). It contained significant amount of polyphenol and protein. The storage study indicated that the juice could be successfully stored for 1 month without any additive and preservative, keeping its natural nutritional qualities, taste, and flavor intact.     

聚苯硫醚中空纤维微滤膜的研究--中空纤维的纺制

讨论聚苯硫醚中空纤维熔融纺丝的主要工艺参数，介绍纺丝温度、氮气通量、熔体挤出速度、空气纺程及卷绕速度对纤维成型的影响，得出最佳纺丝工艺条件。     

Clarification of Pear Juice by Hollow Fiber Ultrafiltration

Hollow fiber ultrafiltration was successfully applied to obtain a clear, amber-colored pear juice. For the three hollow fiber membrane cartridges tested (50,000, 30,000, and 10,000 dalton molecular weight cut-off), the process parameters were optimized and found to be similar. The permeate flux increased with increased transmembrane pressure and then declined. Flux reached a maximum at an average transmembrane pressure of 157 kPa with an average feed stream velocity of 0.15 meters/set at 50°C. Higher flux was obtained at higher temperatures within the temperature limitations of the membrane. Flux decreased linearly with the logarithm of the concentration.     

用中空纤维超滤膜法澄清橙汁

对中空纤维超滤膜法澄清橙汁(Citrus sinensis)进行了研究。试验着重研究了操作压力、温度、物料浓度和进料流速对膜透过速率的影响,并测定了超滤(?)中的营养成分的保存率。还探讨了超滤作为膜蒸馏浓缩预处理的可能性。结果表明,超滤法澄清橙汁是可行的．对果汁营养成分及风味无显著影响。由于超滤除去了果胶等固形物,因此能提高膜蒸馏过程的蒸馏通量。     

Hollow Fiber Ultrafiltration of Maple Sap: A Performance Study

In an attempt to develop new products from maple sap, membrane technology was used to fractionate and concentrate macromolecular components (10,000 daltons or larger). Permeate fluxes increased with transmembrane pressure, reaching a maximum at 190–200 kPa, at 8–10°C. The flux profiles were similar to those of protein solutions and fruit juices. This method of clarification was successfully applied to obtain a clear “cold sterilized” sap. Application of ultrafiltration to maple farms or industries are discussed.     

Cottage Cheese Whey Ultrafiltrate Produced by Hollow Fiber Ultrafiltration,

The composition and volume of ultrafiltrate produced by hollow fiber ultrafiltration of cottage cheese whey with the Bio-Rad Bio-Fiber 50 Miniplant were studied and fitted to models. Temperature, pH, and protein concentration of the feed cheese whey, the flow rate of the feed cheese whey through the Miniplant, and the pressure differential across the membranes were the independent variables in the model fitting. Feed whey temperature and pressure differential across the membranes were the most significant variables affecting the volume of ultrafiltrate produced. Surface plots of response were generated.     

Low Dielectric Constant Material from Hollow Fibers and Plant Oil

Abstract

A new low dielectric constant (k) material suited to electronic materials applications was developed using hollow keratin fibers (HF) and chemically modified soybean oil. High-speed microelectronics is facilitated by preventing the “rubber necking,” or slow-down of electrons on the printed wires through the use of low-k dielectrics. The unusual low-k value of the HF composite material derives both from the air (k = 1) in the hollow microcrystalline keratin fibers (k = 1.7), and the triglyceride molecules (k = 2.7), and is in the range of 1.7 to 2.7, depending on the HF fraction. These values are lower than that of the conventional silicon dioxide (k = 3.8 to 4.2) or epoxy dielectric insulators. Also, the HF dielectric is lightweight (SG < 1) and rigid (Modulus > 2 GPa), with fracture toughness (1.0 MPa m^1/2) and approximates the shape and feel of a silicon dioxide insulator. The coefficient of thermal expansion (CTE) of the new material (67.4 ppm/°C) is low enough for electronic materials applications. Multi-Chip-Module circuit printing results suggest that the low-cost composite made with HF (from avian sources) and plant oil (from soybean) has the potential to replace the dielectrics in microchips and circuits boards in the ever-growing electronic materials field, in addition to many applications as new lightweight composite material.     

HPSEC with Component Analysis of Citrus and Apple Pectins After Hollow Fiber Ultrafiltration

Component analysis of high performance size-exclusion chromatograms was applied to 3.3 × concentration of citrus and apple pectins in dilute solution by ultrafiltration with a hollow fiber module fitted with a 100K membrane. Viscosities of the pectins in retained solutions were unchanged and for citrus pectin there was a 10% reduction of weight fraction of the largest-sized component at the last stage of concentration. A small proportion of apple pectin (radius of gyration = 7 nm) was recovered from one permeate by freeze-drying, and, when redissolved in water, produced large aggregates (z-average diam > 100 nm, measured by dynamic light scattering). Results can provide guidelines for use of the method during industrial pectin processing.     

抗菌中空涤纶纤维性能及产品开发

介绍抗菌中空涤纶纤维的性能特点，其特有的物理化学性能及功能性，决定了产品性能良好，市场潜力广阔。     

Clarification of Apple Juice by Hollow Fiber Ultrafiltration: Fluxes and Retention of Odor-Active Volatiles

Fresh apple juice was clarified in a pilot scale ultrafiltration (UF) unit, with membranes made of polysulfone and polyamide and plate and frame and vacuum drum filters. Flux of apple juice (L/m² hr) vs UF transmembrane pressure data showed an optimum at a pressure of about 140 kPa. Retention of odor-active volatiles was highest in plate and frame filtered apple juice and lowest in vacuum drum filtered juice; the retention of odor-active volatiles in UF juice was intermediate to the two traditional filtration methods. Retention of odor-active volatiles in the permeate of a polyamide membrane was higher than that of a polysulfone membrane.     

Nonfat Dairy Coffee Whitener Made from Ultrafiltered Skimmilk Retentates

Retentates of different protein concentrations obtained by ultrafiltration of skimmilk were freeze-dried and evaluated as nonfat dairy coffee whiteners. Blended in hot coffee the retentate whiteners containing added riboflavin gave a pH of 6.3–6.55, coffee whitening capacity comparable to a commercial nondairy coffee creamer, and acceptable dispersibility. The retentate nondairy whitener with optimum qualities contained 56% total protein, 0.5% fat, 31.0% carbohydrates, 1.92% calcium, and 27 mg sodium/100g.     

Skimmilk Solids as Substrate for the Preparation of Casein Enzymatic Hydrolysates

The time-course hydrolysis curves of low-heat (LH) and high-heat (HH) skimmilk powders (SMP) by trypsin or chymotrypsin were compared to that of sodium caseinate (SC). Rates of hydrolysis, shown to be different (P < 0.05), were SC > LH-SMP > HH-SMP. A two-step ultrafiltration process was applied to hydrolyzed LH-SMP and to hydrolyzed SC, and results were compared. Protein and lactose composition differences between LH-SMP and SC were accentuated by ultrafiltration. The hydrolysis profile (molecular weight distribution of peptides, amino acid content) of LH-SMP tryptic hydrolysate showed a greater proportion of short peptides (<2000 Daltons) and a lower content in GLU, PRO, VAL and TYR, compared to that of SC.     

Influence of Preheating Skimmilk on Water-holding Capacity of Sodium Salts of Caseinates and Coprecipitates

The effect of different preheat treatments of milk on the water-holding capacity of the corresponding sodium caseinates made under laboratory conditions was investigated. Unheated skimmed milk, and milks heated under conditions ranging from 60°C to 120°C for 1 min, respectively, were used for the manufacture of the caseinates. Water-holding capacity was estimated using a method involving equilibration of the powder with excess water and measurement of the volume of released water. Water-holding progressively increased with heating, whereby with 120°C/1 min more than two-thirds of the dispersion volume tested was retained. The whey protein content of the caseinates also varied according to temperature and water-holding capacity.     

Ultrafiltration of whey

Utilization of ultrafiltration for the treatment of whey is increasing in the world dairy industry, due to the progress made in membrane technology itself and a better knowledge of the behaviour of whey components. Pretreatment of whey either by heating accompanied or not with pH adjustment or by ionic strength regulation or by prefiltration has the greatest effect on permeation rate. Preconcentration of whey also improves performances of ultrafiltration equipment. Two new potentialities for whey proteins, made possible by properties of new membranes are also presented.     

超滤技术在米酒精制中的应用

超滤膜分离技术应用于米酒精制,可除去大分子物质（杂质）和微生物,使酒澄清,清酒澄清,清香纯正,延长货架期,试验表明,超滤膜选取HPM64,滤膜有效面积0.64m^2较好,影响超滤产量的主要因素有设备运行压力,料喾料液温度等,采用活性炭处理来酒可脱去原酒中的色素和除去异杂味。(永光）     

Ultrafiltration of pickling bath brine

If the pickling process is finished (after some days or weeks) pickling bath brine (brine) from a meat processing plant consists mainly beside water of sodium chloride, sodium nitrite, proteins and low molecular nitrogen-substances. The raw protein content and the dissolved solids are dependent on the brine age. Usually the brine is discharged to the waste water. That means an increasing of COD (Chemical Oxygen Demand) and of mineral content of the effluent. Membrane processes have been applied to waste water treatment in the food processing industry as an integral part of an effluent processing system for effluent cleaning simultaneously with recovering valuable constituents. First experiments in the field of ultrafiltration (UF) of brine were described by Goldberg [2]. The aim of our experiments was to concentrate and separate the brine proteins and to regenerate the brine by ultrafiltration.     

Characterization of Milk Proteins in Ultrafiltration Permeate

Pasteurized, unhomogenized whole milk was ultrafiltered with a Dorr-Oliver, Series S, plate and frame pilot unit containing seven commercial S-10 polysulfone membranes with a 10,000 molecular weight cut-off. Permeate was collected and protein was isolated from the permeate. Proteins precipitated from the UF permeate by 12.5% TCA were weighed and then characterized by SDS-PAGE. Only a very small amount of protein (.25 g/l) was present in the permeate and approximately 90% of that protein was α-lactalbumin.     

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...     

超滤在荔枝汁澄清中的应用

首次采用聚砜中空纤维膜对荔枝汁进行超滤澄清处理 ,超滤后果汁澄清透明 ,透光率达 99.5% ,无混浊现象 ,较好地保持了原汁的营养成分与风味 ,试验还探讨了超滤工艺参数对膜透过速率的影响