Molecular details of the formation of soluble aggregates during ultrafiltration or microfiltration combined with diafiltration of skim milk

Partitioning of casein and fat in Cheddar cheese manufacturing as affected by cheese milk standardisation: A review

“…Lauzin et al (2020) also found a slight reduction in soluble casein (5% of total) and significantly (P < 0.05) lower Ca and P (% of total) in the serum phase of $2× concentrated skim milk by UF and RO compared with that of skim milk, although the authors claimed there was no change in protein equilibrium. Others claimed that internal structural rearrangements or equilibration cause the release of some micellar casein and Ca-phosphate into the serum phase especially in combination with diafiltration using water (Srilaorku et al 1991;Singh 2007;Ferrer et al 2011Ferrer et al , 2014Li et al 2015;Lin et al 2015;Nair and Corredig 2015;Cos ¸kun et al 2022;Raak et al 2023aRaak et al , 2023b. The solubilisation of caseins was attributed to micellar rearrangements induced by shear and/or pressure and changes in ionic equilibrium (the reverse is also true i.e.…”

Transmembrane Pressure during Micro- and Diafiltration of Milk Affects the Release of Non-Sedimentable Caseins

“…Skimmed milk and retentate samples were centrifuged at 100,000× g and 20 • C for 1 h (Optima L-80 XP; Beckman Coulter, Inc., Brea, CA, USA; rotor type Ti70) to obtain the serum phases for further investigations [16].…”

“…The protein contents of skimmed milk and retentates as well as their centrifugal supernatants were determined using a Gerhardt Dumatherm (C. Gerhardt GmbH & Co.KG, Königswinter, Germany) with a conversion factor of N × 6.38 [16].…”

“…Whey protein content of the permeates was analysed by reversed-phase highperformance liquid chromatography, as described previously in detail [16]. The concentrations of α-lactalbumin and β-lactoglobulin were calculated from the peak areas using calibration curves (0.1-40 mg L −1 ) obtained from commercial standards (Sigma-Aldrich, Steinheim, Germany).…”

“…Concentrating casein micelles by membrane filtration, especially in combination with diafiltration, affects the colloidal structure of casein micelles, which in turn, affects the techno-functional properties of the final concentrate [15]. In particular, the partial dissociation of casein molecules into the serum phase as a consequence of the milieu exchange and increased interactions between casein micelles have been reported [16][17][18]. The presence of non-sedimentable caseins in the serum phase can impart important differences onto the techno-functionality of the concentrates.…”