scholarly journals Influence of Transglutaminase Crosslinking on Casein Protein Fractionation during Low Temperature Microfiltration

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3146
Author(s):  
Ritika Puri ◽  
Francesca Bot ◽  
Upendra Singh ◽  
James A. O’Mahony
Keyword(s):  
Low Temperature ◽  
Hydrophobic Interactions ◽  
Microbiological Quality ◽  
Permeate Flux ◽  
Membrane Pores ◽  
Reversible Dissociation ◽  
Membrane Flux ◽  
Protein Membrane ◽  
Casein Protein ◽  
Isopeptide Bonds

Low temperature microfiltration (MF) is applied in dairy processing to achieve higher protein and microbiological quality ingredients and to support ingredient innovation; however, low temperature reduces hydrophobic interactions between casein proteins and increases the solubility of colloidal calcium phosphate, promoting reversible dissociation of micellar β-casein into the serum phase, and thus into permeate, during MF. Crosslinking of casein proteins using transglutaminase was studied as an approach to reduce the permeation of casein monomers, which typically results in reduced yield of protein in the retentate fraction. Two treatments (a) 5 °C/24 h (TA) and (b) 40 °C/90 min (TB), were applied to the feed before filtration at 5 °C, with a 0.1 µm membrane. Flux was high for TA treatment possibly due to the stabilising effect of transglutaminase on casein micelles. It is likely that formation of isopeptide bonds within and on the surface of micelles results in the micelles being less readily available for protein-protein and protein–membrane interactions, resulting in less resistance to membrane pores and flow passage, thereby conferring higher permeate flux. The results also showed that permeation of casein monomers into the permeate was significantly reduced after both enzymatic treatments as compared to control feed due to the reduced molecular mobility of soluble casein, mainly β-casein, caused by transglutaminase crosslinking.

scholarly journals Application of Ultrafiltration in a Swimming Pool Water Treatment System

Membranes ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 44 ◽  
Author(s):  
Mariusz Dudziak ◽  
Joanna Wyczarska-Kokot ◽  
Edyta Łaskawiec ◽  
Agnieszka Stolarczyk
Keyword(s):  
Ceramic Membrane ◽  
Polymer Membrane ◽  
Swimming Pool ◽  
Permeate Flux ◽  
Limit Values ◽  
Membrane Pores ◽  
Pool Water ◽  
High Regeneration ◽  
Swimming Pool Water ◽  
Ultrafiltration Process

Swimming pool water was treated using an ultrafiltration process using ceramic and polymer membranes for comparison. It was determined that the efficiency of the process depended on the type of membrane used. The polymer membrane decreased the absorbance and concentration of combined chlorine in the pool water to a greater extent than the ceramic membrane. In the case of a ceramic membrane, the concentration of combined chlorine in the permeate exceeded the limit values. During the ultrafiltration process, the permeate flux decreased, causing the blockage of membrane pores. The extent of this phenomenon was similar for both tested membranes. In the case of the ceramic membrane, flushing it with water could significantly restore its initial performance. For both tested membranes, a high regeneration efficiency was observed during chemical treatment with an alkaline solution. SEM photos of the polymer membrane showed low resistance of this polymer to the chlorine present in the swimming pool water.

Partial dealcoholization of red wine by nanofiltration and its effect on anthocyanin and resveratrol levels

2016 ◽  
Vol 22 (8) ◽  
pp. 677-687 ◽  
Author(s):  
Szilvia Banvolgyi ◽  
K Savaş Bahçeci ◽  
Gyula Vatai ◽  
Sandor Bekassy ◽  
Erika Bekassy-Molnar
Keyword(s):  
Low Temperature ◽  
Factorial Design ◽  
Red Wine ◽  
Sensory Attributes ◽  
Transmembrane Pressure ◽  
Nanofiltration Membrane ◽  
Permeate Flux ◽  
Alcohol Content ◽  
Membrane Performance ◽  
Low Alcohol

The present work studies the use of nanofiltration for the production of red wine concentrate with low alcohol content. Factorial design was applied to measure the influences of transmembrane pressure (10–20 bar) and temperature (20–40 ℃) on the retention of valuable components such as anthocyanins and resveratrol, and on the nanofiltration membrane performance. The highest retention of anthocyanin and resveratrol was achieved at low temperature (20 ℃), while the high transmembrane pressure (20 bar) was found to increase the permeate flux considerably. The experiments demonstrated that nanofiltration appears as a valid technique for the production of low alcohol content red wine concentrate. Reduction of volume by a factor of 4, leads to 2.5–3 times more anthocyanins and resveratrol in the wine concentrates. The final new wine products – obtained by using various forms of reconstitution of the concentrated wine – had low alcohol content (4–6 % by volume) and their sensory attributes were similar to those of the original wine.

Effect of Low-Temperature Cleaning of Milking Equipment on the Microbiological Quality of Raw Milk

1983 ◽  
Vol 46 (1) ◽  
pp. 58-60 ◽  
Author(s):  
J. B. STONE ◽  
A. N. MYHR ◽  
I. DAVIE
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Microbiological Quality ◽  
Bacterial Count ◽  
Raw Milk ◽  
Negative Slope ◽  
Plate Count ◽  
Pipeline System ◽  
Standard Plate Count

Effect on the microbiological quality of milk of using a special cleaning detergent (Diversey-Wyandotte, Inc.) for low-temperature (initial 43.8°C, end of wash 35.4°C) washing in a milking parlor pipeline system was compared to regular high-temperature (initial 73°C, end of wash 43.8°C) wash of the system. Microbiological quality of the milk was determined by standard plate count (SPC) and psychrotrophic bacterial count (PBC). Cleanliness of equipment was evaluated by measurement of calcium deposits and visual inspection. Statistical analysis of data over time (June 5 to September 16, 1980) indicated no difference in SPC and PBC of milk between low-and high-temperature washing and, although there was a significant negative slope of PBC with time, this was due to factors other than treatment. Calcium soil deposition and visible evaluation of the equipment were not different for the wash temperatures.

Dynamic Simulations of Alumina Membrane Fouling From Recycling of Semisynthetic Metalworking Fluids

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
John E. Wentz ◽  
Shiv G. Kapoor ◽  
Richard E. DeVor ◽  
N. Rajagopalan
Keyword(s):  
Membrane Fouling ◽  
Fluid Dynamic ◽  
Cross Flow ◽  
Metalworking Fluids ◽  
Alumina Membrane ◽  
Dynamic Simulations ◽  
Membrane Pores ◽  
Alumina Membranes ◽  
Membrane Flux ◽  
Partial Blocking

The recycling of semisynthetic metalworking fluids (MWFs) using alumina membranes is significantly impacted by aggregated MWF microemulsions that cause partial and complete blocking of membrane pores. In this paper, computational fluid dynamic methods are employed to model both a portion of a sintered alumina membrane with tortuous pores and the microemulsions passing through it. Several particle size distributions, measured experimentally at various times through the membrane service life and under two different cross-flow velocities, were used to determine the particle sizes simulated in the flow. Simulated MWF particles smaller than the largest pore diameter were found to completely block the pore through the build-up of a network of particles that blocked smaller diameter inlets and outlets. The results demonstrate as well that significant membrane flux reduction can occur by partial blocking of pore inlets and outlets even in the absence of complete blocking.

scholarly journals Development of hydrophilic GO-ZnO/PES membranes for treatment of pharmaceutical wastewater

2017 ◽  
Vol 76 (3) ◽  
pp. 501-514 ◽  
Author(s):  
O. T. Mahlangu ◽  
R. Nackaerts ◽  
B. B. Mamba ◽  
A. R. D. Verliefde
Keyword(s):  
Phase Inversion ◽  
Hydrophobic Interactions ◽  
Pure Water ◽  
High Energy ◽  
Permeate Flux ◽  
Pharmaceutical Wastewater ◽  
Trace Organic Compounds ◽  
Membrane Performance ◽  
Viable Solution ◽  
Synthesis Approach

Membrane application in water reclamation is challenged by fouling which deteriorates membrane performance in terms of permeate flux and solute rejection. Several studies focusing on antifouling membranes incorporated with nanoparticles have been carried out, but these membranes are not yet a viable solution due to their high energy requirements and inability to completely remove or degrade trace organic compounds (TOrCs). Therefore, this study aims at fabricating polyethersulfone (PES) membranes for treatment of pharmaceutical wastewater by using a unique membrane synthesis approach. PES membranes were synthesised by casting two different solutions before coagulation. Therefore, the synthesis technique was called ‘double-casting phase inversion’. The membranes were impregnated with nanohybrid graphene oxide-zinc oxide (GO-ZnO) to increase their hydrophilicity, rejection of pharmaceuticals (by decreasing membrane-solute hydrophobic interactions), resistance to organic fouling and photodegradation properties. The addition of GO-ZnO increased membrane hydrophilicity and pure water permeability. The rejection of TOrCs and anti-fouling properties were also improved due to a reduction in membrane-solute and membrane-foulant hydrophobic interactions, respectively. In addition to improved TOrC rejection properties and resistance to fouling, GO-ZnO/PES membranes degraded Brilliant Black.

Use of flocculants for increasing permeate flux in anaerobic membrane bioreactors

2014 ◽  
Vol 69 (11) ◽  
pp. 2237-2242 ◽  
Author(s):  
H. Díaz ◽  
L. Azócar ◽  
A. Torres ◽  
S. I. C. Lopes ◽  
D. Jeison
Keyword(s):  
Membrane Filtration ◽  
Common Factor ◽  
Cross Flow ◽  
Membrane Bioreactors ◽  
High Rate ◽  
Permeate Flux ◽  
Membrane Flux ◽  
Anaerobic Membrane Bioreactors ◽  
Flux Increase ◽  
The One

Biomass retention, required for high rate anaerobic wastewater treatment, can be accomplished coupling an anaerobic bioreactor with membrane filtration. However, low flux seems to be a common factor when operating anaerobic membrane bioreactors (AnMBRs). Modification of biomass properties may represent a strategy for improving membrane flux. The addition of flocculants was tested as a tool for flux increase. Six different products were tested in dead-end filtration experiments. Based on the results, two products were selected for cross-flow tests. The one presenting better performance (Nalco MPE50) was tested in a laboratory-scale continuous AnMBR. Results show that the flocculant was able to substantially increase flux. Indeed, the flux-increasing effect was observed for several weeks after flocculant addition. Therefore, the use of flocculants seems to be an interesting tool to cope with temporary increases in required flux.

scholarly journals Effect of Freezing Modes, Storage Time, and Defrosting Methods on Microbiological Quality Parameters of Apricots

2021 ◽  
Vol 51 (1) ◽  
pp. 29-38
Author(s):  
Batuch Guseynova ◽  
Islam Asabutaev ◽  
Tatyana Daudova
Keyword(s):  
Low Temperature ◽  
Microwave Irradiation ◽  
Storage Time ◽  
Initial Period ◽  
Microbiological Quality ◽  
Quality Parameters ◽  
Customs Union ◽  
Anaerobic Microorganisms ◽  
C Storage ◽  
Number Of Microorganisms

Introduction. Low-temperature freezing technology extends the shelf life of perishable fruits as it causes a sharp slowdown in the biochemical and microbiological processes in frozen products. However, it cannot provide complete destruction of microorganisms. The present research featured the reaction of apricot microbiota to the technological techniques of shock freezing. The research objective was to study the effect of low-temperature freezing modes (t = –25, –30, and –35°C), storage time (3 and 9 months), methods, and defrosting modes (in air at t = 5 and 22°C; in water at t = 5, 16, and 22°C; under the effect of microwave irradiation) on the surface microflora of apricots. Study objects and methods. The experiment featured apricots of the varieties Uzden, Untsukulskiy Pozdniy, Honobah, Krasnoshchyokiy, and Shalakh. The microbiological profile of defrosted apricots was based on the State Standard. Results and discussion. Fast freezing at t = –25°C provided a better inhibition of epiphytic microflora than at t = –30 and –35°C: aerobic-mesophilic and optionally anaerobic microorganisms – by 65.2–68.6%, yeast – by 61.5–69.0%, and mold – by 59.3–68.4%, compared to their initial content on fresh apricots. During the initial period of refrigeration storage, the number of microorganisms decreased, while the subsequent nine-month storage (t = –18°C) led to a slight increase in microbiota. After nine months of storage, the number of microorganisms on defrosted fruits, depending on the variety, was the following: aerobic-mesophilic and optionally anaerobic microorganisms – 1.2×103–2.0×103 CFU/g, yeast – 14–26 CFU/g, and molds – 75–108 CFU/g. Defrosting of apricots by microwave irradiation resulted in a greater destruction of microorganisms than after traditional thawing in air and water. Conclusion. The results of microbiological studies indicate that the shock freezing technology ensures the production of quick-frozen apricots that meet the requirements of Technical Regulations of the Customs Union No. 021/2011.

scholarly journals Microflora and Microbiological Quality in Low Temperature Long Time Pasteurized Milk

2010 ◽  
Vol 27 (3) ◽  
pp. 152-157
Author(s):  
Hirokazu OGIHARA ◽  
Nami KIRIBE ◽  
Mami HOSHINO ◽  
Yoshie ODA ◽  
Soichi FURUKAWA ◽  
...  
Keyword(s):  
Low Temperature ◽  
Microbiological Quality ◽  
Pasteurized Milk ◽  
Long Time

scholarly journals Deduction of Surfactants Effect on Performance, Morphology, Thermal and Molecular Properties of Polymeric Polyvinylidene Fluoride (PVDF) Based Ultrafiltration Membrane

2018 ◽  
Vol 63 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Nurul Hannan Mohd Safari ◽  
Abdul Rahman Hassan ◽  
Che Wan Insyirah Che Wan Takwa ◽  
Sabariah Rozali
Keyword(s):  
Polyvinylidene Fluoride ◽  
Sodium Dodecyl ◽  
Tween 80 ◽  
Permeate Flux ◽  
Cross Sectional ◽  
Membrane Pores ◽  
Surfactant Material ◽  
Uf Membranes ◽  
Pore Properties ◽  
Triton X

In membrane making, surfactant material is one of the effective strategies to produce membrane / thin film with optimal and specific properties. This paper addressed the effect of Sodium dodecyl sulphate (SDS), Triton X-100 and Tween 80 as additives for the making of Polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes. The fabricated membranes were analysed in the aspect of performance, morphological structures, thermal properties and molecular orientation. Analysis results showed that the surfactant additives enhanced the membrane performance and properties. Surprisingly, the addition of 2 wt% surfactant increased the permeate flux of bovine serum albumin (BSA) up to 78.14 L/m2h compared to membrane without surfactant with flux at only 2.74 L/m2h. In addition, the role of surfactants on membrane pores and pore properties of PVDF UF membranes were examined. The cross-sectional morphological structures showed that these surfactants led towards the formation of macro-voids and finger-like structures as well as a spongy layer. The surfactants additives also improved the membrane pores and pore properties which reflect to the protein rejection up to 85 % and 78 % of BSA and egg albumin (EA), respectively. Moreover, analysis on the thermal features found that SDS, Triton X-100 and Tween 80 promoted better thermal stability and significantly fine molecular alignment which provided the versatility for the membrane to be used for any applications.

Modeling the impact of permeate flux and hydrodynamic conditions on fouling in submerged hollow fiber membranes

2007 ◽  
Vol 7 (4) ◽  
pp. 111-118 ◽  
Author(s):  
H. Lin ◽  
P.R. Bérubé
Keyword(s):  
Membrane System ◽  
Membrane Module ◽  
Air Sparging ◽  
Hydrodynamic Conditions ◽  
Permeate Flux ◽  
Exponential Relationship ◽  
Membrane Pores ◽  
The Difference ◽  
Fouling Reduction ◽  
The Impact

A series of studies was undertaken to investigate the impact of the system hydrodynamics (i.e., sparging intensity and membrane module configuration) the operating permeate flux and fouling reduction measures on the evolution of the trans-membrane pressure (TMP). The evolution in TMP could be modeled using a simple exponential relationship that incorporated the impact of the air sparging intensity, the membrane module configuration and the backwash cycles on the evolution in TMP. The extent of reversible fouling was a function of the operating permeate flux and the hydrodynamic conditions in the membrane system and could be characterized based on the difference between the operating permeate flux and the critical permeate flux. Reversible fouling could be eliminated during each backwash cycle. The extent of irreversible fouling was relatively low and was expected to be a function of the diffusion and adsorption tendency of foulants within the membrane pores.

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