The effect of soluble solids on the Zetapotential (ξ) of a cloudy apple juice was investigated. Apple juice was enzymatically treated with pectinolytic enzymes and diafiltred with a polysulphone UF membrane (100 kDa) to eliminate soluble solids. Most soluble solids were removed after 4 equivalent sample volumes (ESV) of washing water. During a second period, from 5 to 23 ESV, diafiltration rate...

OBJECTIVES With the aim of rapid, culture-independent identification of microorganisms directly from urine specimens, we developed a diafiltration matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) method. METHODS In this procedure, urine specimens are desalted, fractionated, and concentrated prior to MS analysis. The analytic performance characteristi...

We investigated the surface hydrophobicity index based on different fluorescence probes [1-anilinonaphthalene-8-sulfonic acid (ANS) and 6-propionyl-2-(N,N-dimethylamino)-naphthalene (PRODAN)], free sulfhydryl and disulfide bond contents, and particle size of 80% milk protein concentrate (MPC80) powders prepared by adding various amounts of NaCl (0, 50, 100, and 150 mM) during the diafiltration ...

Insulin is an important biotherapeutic protein, and it is also a model protein used to study amyloid diseases, such as Alzheimer's and Parkinson's. The preparation of the protein can lead to small amounts of aggregate in the solution, which in turn may lead to irreproducible in vitro results. Using several pre-treatment methods, we have determined that pH cycling and diafiltration of the insuli...

Diafiltration is term used reflecting tangential flow filtration (TFF) method of “washing” or removing a permeable molecule (impurities, salts, solvents, small proteins, etc) from a solution in an accelerated method when compared to dialysis tubing. By selecting the appropriate membrane(s), it can also be used to exchange buffers, narrow particle size distributions, modify salt concentrations o...

This study concentrates on time-optimal operation of a general batch diafiltration process. The process model consists of a set of input affine differential equations. We apply Pontryagin’s minimum principle to formulate necessary conditions of optimality. These are then used to identify the shape of optimal control as well as singular surface in concentration space. Comparison is made between ...

Looking at current trends within downstream processing (DSP) of high value bioproducts, it shows that there are ongoing efforts in replacing batch processes by continuous variants. However, a unit procedure which still lacks simple and compact variant is diafiltration. Here, we present such single piece diafiltration equipment achieving buffer exchange up to 99.90%. The device composed 3D-print...

This paper is a preliminary study that deals with time-optimal control of a batch membrane diafiltration processes where fouling of the equipped membrane is pronounced. We account for the membrane fouling by its dynamic model where the pore blocking mechanism applies. It is assumed that due to the deposit of foulants, the radius of membrane pores decreases and the part of membrane surface becom...