Determination of the efficiency of removal of whey protein from sweet whey with ceramic microfiltration membranes

摘要

Our research objective was to measure percent removalof whey protein from separated sweet whey using0.1-μm uniform transmembrane pressure ceramicmicrofiltration (MF) membranes in a sequential batch3-stage, 3× process at 50°C. Cheddar cheese wheywas centrifugally separated to remove fat at 72°C andpasteurized (72°C for 15 s), cooled to 4°C, and heldovernight. Separated whey (375 kg) was heated to 50°Cwith a plate heat exchanger and microfiltered usinga pilot-scale ceramic 0.1-μm uniform transmembranepressure MF system in bleed-and-feed mode at 50°C ina sequential batch 3-stage (2 diafiltration stages) processto produce a 3× MF retentate and MF permeate.Feed, retentate, and permeate samples were analyzedfor total nitrogen, noncasein nitrogen, and nonproteinnitrogen using the Kjeldahl method. Sodium dodecylsulfate-PAGE analysis was also performed on the wheyfeeds, retentates, and permeates from each stage. A fluxof 54 kg/m~2 per hour was achieved with 0.1-μm ceramicuniform transmembrane pressure microfiltration membranesat 50°C. About 85% of the total nitrogen in thewhey feed passed though the membrane into the permeate.No passage of lactoferrin from the sweet whey feedof the MF into the MF permeate was detected. Therewas some passage of IgG, bovine serum albumen, glycomacropeptide,and casein proteolysis products into thepermeate. Β-Lactoglobulin was in higher concentrationin the retentate than the permeate, indicating that itwas partially blocked from passage through the ceramicMF membrane.