Membrane fouling during ultra- and microfiltration of whey and whey proteins at different environmental conditions: The role of aggregated whey proteins as fouling initiators

Temperature dependent membrane fouling during filtration of whey and whey proteins

“…Despite the fact that electrostatic repulsion increases towards higher temperatures, evolution of deposit layer solid height indicates that other deposit forming effects appear that are enhanced at higher temperatures. As described by Steinhauer et al [40] in a previous study, most likely reasons are calcium-and thiol/disulfide-based protein cross-linking.In summary, it can be concluded that the fouling behavior of the major whey protein β-Lg alone was similar to the one of WPI, even though the reactivity of WPI was lower.…”

“…This results in a sharp increase in sulfhydryl reactivity [38,39]. Based on these findings Steinhauer et al [40] could show in a study published earlier that fouling during MF and UF of both β-Lg and WPI suspensions was primary due to covalent protein cross-linking based on thiol/disulfide reactions. Both, progressing monomerization and the partial unfolding result in an increase of the protein hydrophobicity [41].…”

“…Secondly, calcium based cross-linking can occur especially at higher temperature were calcium phosphate becomes increasingly insoluble. Both possibilities were described in a similar filtration set-up by Steinhauer et al in a study published earlier [40].…”

Effect of pH, transmembrane pressure and whey proteins on the properties of casein micelle deposit layers

“…For the formation of deposit layers, a lab-scale dead-end filtration unit (AMICON 8050, Merck-Millipore, Billerica, USA) was used as described in detail elsewhere [12,22,30]. For the experiments, membrane discs with a diameter of 44.5 mm (nominal pore size: 0.025 mm, nitrocellulose, Millipore Corporation, Billerica, USA) were mounted into the filter holder.…”

The impact of membrane pretreatment on the enzymatic production of whey‐derived galacto‐oligosaccharides

“…Although the UF of whey has been actively investigated, there is little information available on UF of demineralized whey. As recently shown by Steinhauer, Marx, Bogendörfer, and Kulozik () investigating the UF of whey, fouling may be accelerated by the formation of whey protein aggregates. Such an unfavorably change in the morphology of fouling layer may also be induced by the absence of some microsolutes or by washing out some compounds from the feed with DF water during operation.…”