Solid-liquid Extraction of Mushroom Solids and Concentration by Reverse Osmosis

Sliced cull mushrooms were extracted at 60°C, 75°C and 90°C using water, 10^-3M sodium metabisulfite or 10^-3M ascorbic acid solutions in a pilot scale counter-current slope diffuser. Extracts were centrifuged, ultrafiltered (UF) by a commercial great resistance, GR-51PP, 50,000 molecular weight cut-off membrane module, and then concentrated to 18-20% soluble solids (SS) by reverse osmosis (RO) using a high resistance, HR-95 membrane module. Primary mushroom volatiles including l-octen-3-ol and 3-octanone were evaluated in raw, extracted, and concentrated juices. The best temperature/solvent extraction system was 75°C in water with 98.2% soluble solids recovery. RO conducted at 10-20°C following the UF process gave an eight- to nine-fold concentration (from 1.8% SS. to 17.5% SS) with 85.1% solute recovery.     

Influence of Reverse Osmosis on Sugar Retention in Apple Juice Concentration

Reverse osmosis (RO) concentration of apple juices from 10-20 Brix using a commercial plate and frame RO system at various temperatures and pressures demonstrated that high resistance (HR) membranes are more efficient in sugar retention than cellulose acetate (CA) membranes. Both temperature and pressure had a significant effect on solute recovery. Optimum processing conditions for HR membranes were 40°C at 40 bar, 98% sugar recovery and 16.7L/m²/hr average processing capacity (flux). An increase of 3-4% average processing capacity per 1°C increase in temperature was observed. Operating conditions and membranes did not modify fructose content or glucose/fructose ratio of the RO concentrated juices.     

Mushroom Blanch Water Concentration by Membrane Processes

Mushroom blanch water was concentrated by ultrafiltration (UF) and reverse osmosis (RO). UF prefiltration was essential in preventing severe fouling during the RO process. When the UF blanch water permeate was processed by RO, linear relationships between pressure and flux were observed at all concentrations tested. The blanch water was concentrated by UF/RO from 2% to 13% total solids at 60°C and 120 KPa/5000 KPa operating pressures with flux higher than 15 L/m² hr. Maximum concentration obtained was approximately 20% total solids with 90% recovery of the nonvolatiles. Recoveries of some major volatiles were above 50%. Panelists could not differentiate the original from the reconstituted blanch waters in sensory evaluations.     

STUDIES ON THE CLARIFICATION AND CONCENTRATION OF BEETROOT JUICE

Studies on the clarification and subsequent concentration of beetroot juice were carried out. The juice was clarified using enzyme, fining agent (FA), centrifugation and ultrafiltration (UF), while reverse osmosis (RO) and thermovacuum evaporation were used for concentration. The juices were concentrated to 23–25°Brix, and the physicochemical characteristics were evaluated at different stages of processing on the basis of clarity, permeate flux, °Brix, acidity, sugars, pigments and CIE L*, a* and b* (lightness, redness and yellowness, respectively) color values. Average permeate flux during RO was found to be highest (36.08 liters per square meter of membrane per hour [L/m²h]) in the case of enzyme treatment, followed by UF juice, and lowest (30.33 L/m ² h) in the case of enzyme and FA treatments. In terms of clarity of concentrate, the highest value was obtained for juices pretreated with enzyme and UF. Pigment content and L*, a* and b* values showed that pigment loss was higher in the case of RO‐concentrated juice pretreated with enzyme. Comparative evaluation in terms of clarity, color and chemical parameters showed that concentrates obtained using both techniques were comparable.     

Solute and Enzyme Recoveries in Apple Juice Clarification using Ultrafiltration

Enzyme treated apple juices, obtained after pressing on a commercial processing line, were clarified by UF using a plate and frame system. The 50,000 molecular weight cut-off membranes operated at 50°C and 5 bar pressure yielded average recovery of 99.6% and 99.3% soluble solids and titratable acids, respectively, in the permeate and rejected 36.3% of the residual pectinase activity which was available for possible reuse. Proper membrane cleaning to maintain high flux was very important in UF clarification; a 1% Ultrasil solution was more efficient than a 0.1% NaOH solution and reduced need for centrifugation and/ or vacuum filtration prior to UF.     

Preconcentration of Apple Juice by Reverse Osmosis

Single strength apple juices (10° Brix) were processed by reverse osmosis to 20-25°Brix, primarily at 20°C. A pilot scale plate and frame UF-RO system equipped with cellulose acetate (CA) membranes, CA-865 and/or CA-990, or high resistance (HR) membranes, HR-95 and/or HR-98, was operated at pressures of 35-45 bar. At 45 bar, the larger pore-sized CA-865 possessed the highest processing capacity of 26.9 L/m²/hr (from 10°Brix to 20°Brix) and concentration limits of 35° Brix, but had low recovery of solutes and flavor volatiles. The HR-95 and HR-98 had similar processing capacities of 15-16 L/m²/hr and concentration limits of 20-25° Brix at 45 bar. The recoveries of 97% solutes and 87% apple flavor volatiles were obtained using either the HR-95 or the HR-98.     

Microfiltration and Ultrafiltration Ceramic Membranes for Apple Juice Clarification

Depectinized control (CTJ) and ascorbic acid treated (AAJ) apple juices were filtered through microfiltration (MF, 0.2 m) and ultrafiltration (UF, 0.02 m) ceramic tubular membranes. Under optimal conditions (8 m/s, 414 kPa and 50°C), the UF membrane resulted in higher steady state flux and less fouling than the MF membrane for both juices. AAJ produced by addition of AA at milling had lower flux for both MF and UF. The chemical, physical and sensory properties of apple juices from MF and UF membranes were similar and changes during storage were comparable.     

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.     

应用膜分离技术改进泰乐菌素提取工艺

应用超滤-纳滤组合膜分离技术对泰乐菌素发酵液进行提纯和浓缩,以取代原有的板框过滤。对不同材料、截留分子量的超滤和纳滤膜的筛选结果表明,超滤膜宜采用PES-150聚醚砜膜,纳滤膜宜采用聚酰胺复合纳滤膜DL 2540。发酵液采用硅藻土预处理,且超滤过程恒容累积加水250L,能提高82%的膜通量,此时泰乐菌素的收率达97%。发酵液超滤液与原板框滤液的泰乐菌素组分纯度基本一致,但超滤液萃取效果更好,萃取收率提高了20%～26%。DL 2540纳滤膜对超滤液进行3.5倍浓缩,平均通量可达41.3 L/(m2.h),通过纳滤收率可达99%,纳滤浓缩液萃取无乳化现象,所得萃取液的色度也较低。     

CONSEQUENCES of FOULING and MACROMOLECULE ADSORPTION ONTO ULTRAFILTRATION MEMBRANE FOR PINEAPPLE JUICE PROCESSING

Pineapple juice samples were ultrafiltrated using a polysulfone 10,000 molecular weight cut-off (MWCO) membrane. However, to facilitate operations, the ultrafiltration experiments were preceeded by fractionation of juice samples using sequentially Microfiltration/Diafiltration and Ultrafiltration/Diafiltration with 8 μm; 0.4 μm; 0.2 μm and 0.1 μm membranes, using three specific experimental procedures. the 10,000 MWCO membrane was cleansed using a 40°C IN NaOH solution for a minimum of 30 min, to restore optimal membrane water permeation flux. the effects of selective fractionation processes, pretreatments (using antifoaming agent, hemicellulase, and ammonium sulfate saturation), on permeation rates, concentration levels, protein rejection and protein yields were determined. Water permeation fluxes, measured before and after each UF operation showed a dramatic flux drop from 313 L/hm² to 91 L/hm² within seven successive 10,000 MWCO membrane experiments. This occurred inspite of suitable membrane washing conditions, pretreatments and selective fractionation processing of samples. the modification, mainly due to fouling, of the integrity of the 10,000 MWCO membrane relative to concentration level was investigated.     

Effects of Fruit Storage and Processing on Clarity, Proteins, and Stability of Granny Smith Apple Juice

Granny Smith apples were processed into juices and concentrates from fruits which had been stored at 1°C for three months (short-term, ST) and nine months (long-term, LT). Total soluble proteins decreased with storage time of fruits. Juices processed from ST fruits were more resistant to haze formation (heat stability test) than those processed from LT fruits. For juices processed from ST apples, haze formation was related to proteins in the MW range of 21,000 to 31,000 daltons. For juices processed from LT apples, haze formation was not only related to proteins but also to other components in the juices. Fining was recommended to prevent haze and sediment formation.     

Composition of Some Organic and Inorganic Compounds in Reverse Osmosis-Concentrated Citrus Juices

Orange, grapefruit and lemon juices were concentrated over twofold in a pilot scale reverse osmosis (RO) process using a commercially available membrane system. Major sugars, acids, vitamin C, aroma volatiles and over 20 minerals were examined in feed, concentrate and permeate streams. Typically, 15–20 aroma compounds were identified in feed juices and concentrates. Compared with less volatile compounds (e.g., ethyl butyrate, limonene), poorer retention during processing was noted for more volatile molecules (methanol, acetaldehyde, ethanol). °Brix of membrane concentrates were orange (25.3°B), grapefruit (25.1°B) and lemon (22.5°B). Vitamin C was rejected efficiently by the membrane. Mineral analyses showed similar elemental contents in feed and concentrate and insignificant concentration in permeate streams.     

Ultrafiltration and Reverse Osmosis of the Waste Water from Sweet Potato Starch Process

The primary waste water discharged from pilot plant scale sweet potato starch manufacturing was processed by ultrafiltration (UF). The UF permeate was then concentrated by reverse osmosis (RO). Growth of microorganisms in waste water would reduce the flux of UF. When the feed velocity of UF was higher than 2.5 m/sec, its positive effect on permeation rate was no longer existent. Relationships between transmembrane pressure and permeate flux were linear at all tested concentrations. UF filtered protein and calcium reduced two-thirds of the biochemical oxygen demand (BOD) and half the chemical oxygen demand (COD) at weight concentration ratio (WCR) of 5. With RO the rest of the components were recovered and BOD and COD were reduced more than 99% and 98%, respectively, at a WCR of 6.     

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.     

Pilot-scale ceramic membrane filtration of skim milk for the production of a protein base ingredient for use in infant milk formula

The protein composition of bovine skim milk was modified using pilot scale membrane filtration to produce a whey protein-dominant ingredient with a casein profile closer to human milk. Bovine skim milk was processed at low (8.9 °C) or high (50 °C) temperature using ceramic microfiltration (MF) membranes (0.1 μm mean pore diameter). The resulting permeate stream was concentrated using polyethersulfone ultrafiltration (UF) membranes (10 kDa cut-off). The protein profile of MF and UF retentate streams were determined using reversed phase-high performance liquid chromatography and polyacrylamide gel electrophoresis. Permeate from the cold MF process (8.9 °C) had a casein:whey protein ratio of ∼35:65 with no α_S- or κ-casein present, compared with a casein:whey protein ratio of ∼10:90 at 50 °C. This study has demonstrated the application of cold membrane filtration (8.9 °C) at pilot scale to produce a dairy ingredient with a protein profile closer to that of human milk.     

茶饮料生产中膜分离技术的应用研究

综述了国内外关于超滤（UF）和反渗透（RO）技术在茶类饮料生产过程的澄清工艺和浓缩工艺中对茶饮料主要化学成分和品质的影响。并对超滤（UF）和反渗透（RO）膜的选择、工艺流程技术进行了分析评价。     

Influence of flocculation and adsorption as pretreatment on the fouling of ultrafiltration and nanofiltration membranes: application with biologically treated sewage effluent

Membrane fouling is a critical limitation on the application of membranes to wastewater reuse. This work aims to understand the fouling phenomenon which occurs in ultrafiltration (UF; 17500 molecular weight cutoff (MWCO)) and nanofiltration (NF; 250 MWCO) membranes, with and without pretreatment. For this purpose, the molecular weight (MW) distribution of the organics has been used as a parameter to characterize the influent, the permeate, and the foulant on the membrane surface. The variation of foulant concentration on the membrane due to pretreatment of the influent by flocculation and/or adsorption was investigated in detail. With the UF membrane, the peak of the MW distribution of organics in the permeate depended on the pretreatment; for example, the weight-averaged MW (Mw) of 675 without pretreatment shifted down to 314 with pretreatment. In the case of the NF membrane, the Mw of organics in the permeate was 478 (without pretreatment) and 310 (with flocculation followed by adsorption). The Mw of the organics in the foulant on the membrane surface was 513 (UF) and 192 (NF) without pretreatment and 351 (UF) and 183 (NF) after pretreatment with flocculation followed by adsorption, respectively. Without the pretreatment, the foulant concentration was higher on both membranes. The difference was more significant on the UF membrane than on the NF membrane. For both membranes, the flocculation-and-then-adsorption pretreatment proved very effective.     

PROCESSING WHEY-TYPE BY-PRODUCT LIQUIDS FROM COTTONSEED PROTEIN ISOLATION WITH ULTRAFILTRATION AND REVERSE OSMOSIS MEMBRANES

Cottonseed wheys resulting from protein isolation from cottonseed flour were processed by semi-permeable ultrafiltration (UF) and reverse osmosis (RO) membranes. The UF membrane fractionated the soluble whey constituents by retaining protein and passing through salts, carbohydrates and other non-protein components along with most of the water. The UF membrane effluent was then processed through an RO membrane to recover a secondary product containing the whey materials not retained in the protein product from the UF membrane. The feasibility of recycling effluent from the RO membrane for reuse in subsequent protein extractions was demonstrated. Thus, the threat of water pollution from effluent disposal could be eliminated completely and process water requirements drastically reduced. Spray-dried UF protein concentrates were tested for utilization in protein fortification of breads and noncarbonated beverages and as whipping products. They exhibited commercial potential for use in these food applications. The economics of processing the whey-type liquids by the membrane process under investigation were analyzed. Membrane processing of wheys by each of two alternative whey processing systems proved to be economically attractive.     

Volatile odour components and sensory quality of fresh and processed mandarin juices

Twelve volatile compounds were quantified by gas chromatography/mass spectrometry in juices from two Spanish mandarin varieties, Fortuna and Clemenules. Fresh Clemenules juice contained a higher amount of total volatile compounds (61.1 ± 1.1 mg L⁻¹) than fresh Fortuna juice (48.8 ± 2.5 mg L⁻¹), with D ‐limonene (97.1%), myrcene (1.7%), sabinene (0.5%), α‐pinene (0.3%) and linalool (0.3%) being the predominant compounds. Pasteurisation of the mandarin juices (20 s at 98 °C) caused a significant reduction (∼12%) in vitamin C concentration. On the other hand, vitamin C was stable during storage of the juices for 60 days in aseptic tanks at 2 °C. Volatile compounds, however, were more affected by storage in aseptic refrigerated tanks (2 °C) than by heat treatment. Pasteurisation caused a mean decrease in the total concentration of volatile compounds of about 18%, while, after a storage time of 60 days, 36% of total volatiles present in the juices after pasteurisation were lost from both Fortuna and Clemenules juices. Significant reductions in the concentrations of D ‐limonene, myrcene, sabinene, α‐pinene and linalool were found, while those of α‐terpineol and terpinen‐4‐ol increased. Copyright © 2006 Society of Chemical Industry