The pre-concentration of milk by nanofiltration in the production of Quarg-type fresh cheeses

Abstract

[7]. In addition, a lower transmembrane pressure (TMP) than that applied to RO can be used to obtain comparable fluxes. NF membranes wears ionogenic groups, and, consequently, their separation mechanisms involve both steric (sieving) and electrical (Donnan) effects. Partial loss of electrolytes is advantageous to several applications. A typical example is whey concentration: the use of NF yields partially demineralised INTRODUCTIONNanofiltration is a relatively new pressure-driven membrane process with growing applications to various fields such as food industry and water treatment. A peculiar feature of NF membranes is their low retention towards monovalent ions, whereas retention of higher ions and sugars is comparable to that obtained by reverse osmosis Original articleThe pre-concentration of milk by nanofiltration in the production of Quarg-type fresh cheeses Abstract -Milk pre-concentration by nanofiltration (NF) was proposed for fresh Quarg-type cheese manufacturing. NF process modelling by means of model solutions showed that transmembrane pressure and flow velocity had a clear effect on both permeation flux and lactose retention, that a rise in temperature resulted in an increase in permeate flux and a decrease in lactose retention, and that monovalent ion retention depended heavily on the concentration. Milk was concentrated 2 to 3 times by NF. Permeation fluxes were in a range of 10 to 41 kg·h -1 ·m -2 and solute retentions were in accordance with the results from model solutions. Quarg obtained using milk NF retentates was naturally sweeter (61.52 ± 4.30 g·L -1 lactose) than traditional fresh cheese and had a high calcium content (2.01 ± 0.33 g·L -1 ) and no bitter taste. Whey had a higher total solids and lactose content and, therefore, required an easier treatment than normal Quarg acid whey.

Studying a new anti-polarization method in the process of ultrafiltration of skimmed milk

“…The whole milk ultrafiltration turns 45.1 % of solids, including 96.5 % of lactose and 60.6 % of mineral salts, into filtrates. Similar results are obtained by ultrafiltration of skimmed milk [3,4].…”

“…-pre-concentrate milk [4,5]; -extract/isolate a complex of milk proteins and, simultaneously, separate lactose and mineral substances [6,7];…”

Comparison of the Behavior of Two Nanofiltration Membranes for Sweet Whey Demineralization

“…Concentration and demineralization of whey have been important applications for membrane technologies in the dairy industries (Van der Horst et al, 1995;Rä sä nen et al, 2002). Nanofiltration processes have been studied to reduce the losses of lactose and to improve the capability to demineralize whey (Jeantet et al, 1996;Mucchetti et al, 2000;Atra et al, 2005).…”

Tecnologías de membranas en la agroindustria láctea

“…Puede considerarse como un proceso dual, pues generalmente se aplica en conjunto con una ósmosis inversa. Suele involucrar una separación en base a tamaño molecular y otra basada en la carga eléctrica, lo que en teoría permite apartar los iones monovalentes de los polivalentes; esto para un punto de corte de las moléculas que ronda los 200 a 1.000 daltons, para tamaños de poro inferiores a 2 nm y velocidades de flujo cercanas a 10-41 kg/h*m 2 (Mucchetti et al 2000).…”