Filtration of Milk Fat Globule Membrane Fragments from Acid Buttermilk Cheese Whey

Abstract

The proteins and polar lipids present in milk fat globule membrane (MFGM) fragments are gaining attention for their technological and nutritional properties. These MFGM fragments are preferentially enriched in side streams of the dairy industry, like butter serum, buttermilk, and whey. The objective of this study was to recover MFGM fragments from whey by tangential filtration techniques. Acid buttermilk cheese whey was chosen as a source for purification by tangential membrane filtration because it is relatively rich in MFGM-fragments and because casein micelles are absent. Polyethersulfone and cellulose acetate membranes of different pore sizes were evaluated on polar lipid and MFGM-protein retention upon filtration at 40 degrees C. All fractions were analyzed for dry matter, ash, lipids, proteins, reducing sugars, polar lipid content by HPLC, and for the presence of MFGM proteins by sodium dodecyl sulfate-PAGE. A fouling coefficient was calculated. It was found that a thermocalcic aggregation whey pretreatment was very effective in the clarification of the whey, but resulted in low permeate fluxes and high retention of ash and whey proteins. By means of an experimental design, the influence of pH and temperature on the fouling and the retention of polar lipids (and thus MFGM fragments), proteins, and total lipids upon microfiltration with 0.15 microM cellulose acetate membrane was investigated. All models were highly significant, and no outliers were observed. By increasing the pH from 4.6 to 7.5, polar lipid retention at 50 degrees C increased from 64 to 98%, whereas fouling of the filtration membrane was minimized. A 3-step diafiltration of acid whey under these conditions resulted in a polar lipid concentration of 6.79 g/100 g of dry matter. As such, this study shows that tangential filtration techniques are suited for the purification of MFGM fragments.

Composition, Properties and Nutritional Aspects of Milk Fat Globule Membrane – A Review

“…In the MFGM, polar lipids and proteins are closely associated so they will probably co-migrate during dairy processing. As seen in Table 5 and figures in various references [Corredig et al, 2003;Roesch et al, 2004;Rombaut et al, , 2007, dairy products rich in polar lipids are also enriched in MFGM proteins. As such, buttermilk and butter serum are suitable as sources for the isolation of MFGM material; the latter is the richest source of MFGM material on dry basis.…”

“…Many attempts have been performed to isolate MFGM from buttermilk. By using micro-and ultrafiltration, the transmission of components through the membrane was found to depend on filtration conditions such as temperature, pH, pore size and type of membrane material and the type of buttermilk [Morin et al, 2004Rombaut et al, 2007].…”

“…Addition of sodium citrate agent causes dispersion of not only casein micelles but also MFGM fragments . Whey buttermilk , the aqueous fraction obtained by churning of whey cream which is separated from cheese whey, and acid buttermilk whey [Rombaut et al, 2007], the aqueous fraction obtained by acidification of sweet-cream buttermilk, were considered favorable for MFGM isolation by filtration due to absence of casein micelles. As expected, transmission of MFGM proteins through the membrane was lower when using whey buttermilk compared with regular buttermilk .…”

“…At optimized conditions, 98% of the polar lipids from the acid buttermilk whey were recovered in the retentate. Thermocalcic aggregation of the whey before filtering aids to clarify the whey, but also results in low permeate fluxes and high retention of ash and whey proteins [Rombaut et al, 2007].…”

Comparison of emulsifying properties of milk fat globule membrane materials isolated from different dairy by-products

“…Trisodium citrate (1%, wt/wt) was added to dissociate casein micelles into casein components that were small enough to permeate the membrane during the filtration process (Corredig et al, 2003;Rombaut et al, 2006). For BM whey, the pH was adjusted to 7.5 by adding 1 N KOH before MF (Rombaut et al, 2007a). Cross-flow MF was performed in combination with continuous diafiltration (the rate of water addition was equal to the permeate rate) to separate the MFGM fragments from the 2 materials (reconstituted BM and BM whey; Phan et al, 2013).…”