scholarly journals Change of juice color during raspberry processing in fruit juice and fruit juice concentrate

2006 ◽  
Vol 51 (1) ◽  
pp. 99-115 ◽  
Author(s):  
Predrag Vukosavljevic ◽  
Branka Bukvic ◽  
Miodrag Jankovic ◽  
Tanja Petrovic ◽  
Snezana Stevanovic
Keyword(s):  
High Efficiency ◽  
Fruit Juice ◽  
Cross Flow ◽  
Hydraulic Press ◽  
Extraction Yield ◽  
Single Stage ◽  
Separation Processes ◽  
Laboratory Equipment ◽  
Lower Viscosity ◽  
Total Anthocyanins

A change of anthocyanins under different conditions of enzymatic treatments, clarification and concentration was determined. A pectin preparation Klerzyme?120, manufactured by DSM, France, specific for "sour fruits" with pH below 3.2, was used for maceration and depectinization. Experiments were carried out by a laboratory hydraulic press. Raw raspberry juice was clarified either by membranes separation processes or by traditional treatments using gelatin and bentonite. For microfiltration and ultrafiltration processes, membrane cut-off should not be below 30,000 g/mol to prevent any color loss. Experiments with membrane separations processes were carried out with five different membranes. A raw depectinized raspberry juice was clarified by cross-flow microfiltration and ultrafiltration using ceramic tubular membranes and hollow fiber polymeric membranes of a molecular weight cut-off of 300, 50 and 30 kg /mol or with a mean pore size of 0.2 urn in the case of microfiltration. Fruit juice concentrations were carried out by a laboratory equipment for vacuum evaporation. Extraction yield by a laboratory hydraulic press was the same in case of single-stage maceration and two-stage maceration. However, due to a lower viscosity, it was observed that single-stage process provides raspberry juice with more color and high efficiency of extraction. It was noticed that thermal breaks of raspberry pulp provide juice containing more total anthocyanins. The clarification using gelatin and bentonite removed about 50% total anthocyanins, while a clarification by a cross-flow ultrafiltration using Carbosep M9, M8 and M7 membranes achieved the highest level of color loss. Total color loss after concentration was 70%. The best results in color protection were observed by a microfiltration through Kerasep membrane, due to its relatively large pores (0.2?m). .

Realization of Optional Method of Determining the Concrete's Freeze-Thaw Resistance with Help of Dilatometer

2014 ◽  
Vol 1082 ◽  
pp. 258-264
Author(s):  
Olga Pertseva ◽  
Sergey Nikolskiy
Keyword(s):  
Theoretical Analysis ◽  
High Efficiency ◽  
Nondestructive Method ◽  
Labor Input ◽  
Laboratory Equipment ◽  
Freeze Thaw

It’s really necessary to determine freeze-thaw resistance of concrete faster and correctly.The offered method is based on measurement of long strength by nondestructive method, based onacoustic issue. Also dilatometer is used. During this research, the theoretical analysis of concrete'sspecimen dependence on freeze-thaw resistance and energy, which is emitted by a specimen duringdestruction, has been carried out. Freeze-thaw resistance of a specimen is calculated as themathematical relation of these energies. Correctness of the offered method is proved byexperiments. The offered method is characterized by small labor input, high efficiency and a wideapplication scope, but special laboratory equipment is needed.

High Efficiency Combined Aggregate – Submerged Combustion Melter–Electric Furnace for Vitrification of High-Level Radioactive Wastes

2004 ◽  
Author(s):  
L. S. Pioro ◽  
I. L. Pioro
Keyword(s):  
Electric Furnace ◽  
High Efficiency ◽  
High Capacity ◽  
Main Idea ◽  
Melting Process ◽  
Radioactive Wastes ◽  
Single Stage ◽  
Interface Surface ◽  
High Level ◽  
Submerged Combustion

It is well known that high-level radioactive wastes (HLRAW) are usually vitrified inside electric furnaces. Disadvantages of electric furnaces are their low melting capacity and restrictions on charge preparation. Therefore, a new concept for a high efficiency combined aggregate – submerged combustion melter (SCM)–electric furnace was developed for vitrification of HLRAW. The main idea of this concept is to use the SCM as the primary high-capacity melting unit with direct melt drainage into an electric furnace. The SCM employs a single-stage method for vitrification of HLRAW. The method includes concentration (evaporation), calcination, and vitrification of HLRAW in a single-stage process inside a melting chamber of the SCM. Specific to the melting process is the use of a gas-air or gas-oxygen-air mixture with direct combustion inside a melt. Located inside the melt are high-temperature zones with increased reactivity of the gas phase, the existence of a developed interface surface, and intensive mixing, leading to intensification of the charge melting and vitrification process. The electric furnace clarifies molten glass, thus preparing the high-quality melt for subsequent melt pouring into containers for final storage.

scholarly journals Microfiltration with periodic gas backwashing as an alternative technique for increasing permeate flux

2018 ◽  
Vol 72 (2) ◽  
pp. 59-68
Author(s):  
Tijana Urosevic ◽  
Dragan Povrenovic ◽  
Predrag Vukosavljevic ◽  
Ivan Urosevic
Keyword(s):  
Steady State ◽  
Flow Rate ◽  
Driving Force ◽  
Fruit Juice ◽  
Cross Flow ◽  
Fruit Juices ◽  
Transmembrane Pressure ◽  
Permeate Flux ◽  
Cross Flow Filtration ◽  
Flow Filtration

In this paper, the influence of operating parameters (transmembrane pressure, temperature, the flow rate of retentate) on the cross - flow microfiltration of synthetic fruit juice and periodic backwashing with air was examined. In the experiments, the Kerasep W5 ceramic membrane with a separation limit of 0.2 ?m was used. The results of experiments in which different transmembrane pressures were used showed that stationary fluxes, at stationary conditions, after 60 minutes, have similar values. So, it can be concluded that the value of the driving force is irrelevant at steady state conditions. However, until the steady state conditions are established, a positive effect of the increase in the driving force is opposed to the negative effect of the increased polarization resistance, as a result of the driving force increase. Thus, the optimal transmembrane pressure was determined amounting to 2 bars. The optimum temperature of the process of clearing the fruit juices by microfiltration is reported as 55?C. Higher temperatures are not used due to a degrading effect on the chemical composition of the juice and a long microfiltration process. With an increase in the temperature of retentate from 22?C to 55?C, the permeate flux increased up to 60%. Increasing the flow rate of retentate reduces the thickness of the formed layer on the surface of the membrane. Due to limitations of the experimental setup and the large surface area of the membrane, the specific velocity of the retentate was low, so that the effects of cross-flow filtration were absent. The use of cross-flow filtration is one of the main requirements for increasing permeate flux, but in the present case it was in overall insufficient, so we have applied periodic air backwashing for improving fruit juice flux during membrane clarification. With this technique, the deposited layer on the membrane is lifted and the permeate flux is maintained at high levels preventing establishment of the steady state in the low flux zone. The time spent for the periodic backwashing was low as compared to the benefits of the increase in the collected permeate quantity. In all experiments with periodic backwashing with air, the collected permeate quantity is higher for up to 72.5 % as compared to experiments without backwashing. By increasing the backwashing duration, the flux increase is up to 5 %, which can be significant for microfiltration at industrial scale. Therefore, this technique is certainly recommended for microfiltration in the production of fruit juices.

Development of High Efficiency and Low Noise Cross-Flow Fans for Room Air Conditioner Indoor Unit

2014 ◽  
Author(s):  
Hironobu Yamakawa
Keyword(s):  
High Efficiency ◽  
Length Distribution ◽  
Cross Flow ◽  
Low Noise ◽  
Navier Stokes ◽  
Outer Diameter ◽  
Air Conditioner ◽  
Blade Edge ◽  
Sinusoidal Shape ◽  
Cross Flow Fan

Cross flow fans are used for fan systems in a household room air conditioner indoor unit. In recently, in the view of environmental problem and cost saving, energy saving performance is important specification for users. Reducing fan motor electric power consumption is effective for this purpose. And also low noise fans are needed for comfortable circumferences. To meet these user needs, we developed a high efficiency and silent cross flow fan using CFD (Computational Fluid Dynamics) and experiments. In CFD, numerical model is calculated by commercial software using steady state, Reynolds-averaged Navier-Stokes (RANS) and k-ε turbulent flow model. The developed cross flow fan is geometrically characterized by the solidity (the ratio of the blade pitch and blade cord length) distribution, and the blade edge shape. The solidity average of developed fan was larger than the conventional fan and the solidity distribution was smooth. And the developed fan has the sinusoidal shape of the outer diameter edge. This sinusoidal shape edge makes pressure distribution on the tongue to be more dispersed compare to that of conventional straight edge so that tonal noise was restrained.

The new concept of flux enhancement during cell separation with MF/UF processes

2001 ◽  
Vol 1 (5-6) ◽  
pp. 381-386
Author(s):  
A. Kołtuniewicz
Keyword(s):  
Cell Separation ◽  
High Efficiency ◽  
Membrane Surface ◽  
Cross Flow ◽  
Dry Mass ◽  
High Energy ◽  
Process Conditions ◽  
Permeate Flux ◽  
Flux Enhancement ◽  
Flow Systems

The microfiltration and ultrafiltration processes are considered as matured membrane processes that are well established in industrial practice. Nevertheless, the main obstacles of their further development in the new competitive implementations are the economical problems. The key economic factors are permeate flux and energy consumption. However, although the cross-flow systems enable us to attain higher flux, it is usually very expensive. The high energy is consumed to maintain circulation velocity of the retentate that is sufficient for sweeping out the retained component from the membrane surface. Moreover in the case of cells separation the high intensity of the fouling and low cake permeability makes it necessary to apply additional efforts, such as backflushing, backpulsing, promoters of turbulence, vibrations, ultrasounds and many other. Therefore, dead-end systems are still quite competitive with cross-flow, especially for diluted (less than 0.5% of dry mass) suspensions or solutions. Cell separation with membranes is one of the most vivid problems for modern biotechnology, wastewater and water treatment. Membranes offer mild process conditions and high selectivity of separation. This enables us to solve a variety of problems such as cell culturing, fractionation, concentration, purification and sterilisation. The selected cells may be precisely separated from other components of broth and subsequently directed into the reaction space again in good conditions to ensure a quasi-continuous mode of operation. Moreover, membranes enable us to attain high efficiency of the bioconversion by removal of all product and inhibitors directly from the bioreactor. This is the reason for the huge interest in cell separation with membranes. The idea of the paper was to present the new concept of flux enhancement for cell separation on membranes. This concept lies in taking advantage of the specific rheological nature of biopolymers, which are the main foulants. The biopolymers retained on the membrane surface (i.e. on the top layer) can be applied as a lubricant for the cells that can settle on such a ‘movable layer’. As is shown, further in the paper, the thickness of the moving layer is lower and the flux is greater. The common movement of the cells and gel layer is very convenient from the cells integrity point of view. However the hydrodynamic conditions always play an important role in cross-flow systems; the resistance of ultrafiltration membranes may be reduced much more when compared with more open microfiltration membranes.

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