Bovine Milk Fat Globule Membrane Proteins Are Affected By Centrifugal Washing Processes

Abstract

The impact of washing on the release of proteins from the milk fat globule membrane (MFGM) was examined by applying washing procedures with different degrees of stringency to milk fat globule (MFG) surfaces in simulated milk ultrafiltrate buffer solution. Three washing methods, M1 (3000g, 5 min, three washes), M2 (3750g, 15 min, one wash), and M3 (15000g, 20 min, three washes) were chosen. MFG ζ-potential increased after M3 washing (P < 0.05), suggesting surface damage. For M1, in which the native MFG surface was least damaged, cluster of differentiation 36 (CD 36) and periodic acid schiff 6/7 proteins were more strongly bound to the MFGM compared with other major membrane proteins. For M3, CD 36 together with fatty acid-binding protein was more strongly bound to the MFGM. Washing by centrifugation and redispersal of the fat globules damaged the MFGM, with release into the aqueous phase of some membrane-associated proteins. The current results show the impact of washing processes on retention of functional MFGM proteins.

Technical difficulties and future challenges in isolating membrane material from milk fat globules in industrial settings – A critical review

“…This was explained by the possibility of membrane component reorganisation after the drastic processing impact of homogenisation. Zheng, Jim enez-Flores, and Everett (2013) showed using CLSM that structural changes to the MFGM took place after washing of cream (see Fig. 6).…”

“…Britten et al (2008) showed that the total protein content of buttermilk (including caseins, whey proteins, and MFGM proteins) was reduced from 24.5 g L À1 to 5.2 g L À1 after one washing step with 10 times the starting volume of UF Saline solution (0.9% NaCl) Cavaletto et al, 1999;Cebo et al, 2010;Fortunato et al, 2003;Keenan et al, 1971;Patton, 1982 Phosphate Cavaletto et al, 1999;Cebo et al, 2010;Dickow et al, 2011;Horisberger et al, 1977;Kathriarachchi et al, 2014;Liao et al, 2011;Mather & Keenan, 1975;Nejjar et al, 1986;Ong et al, 2010;Patton, 1982;Patton & Huston, 1986;Sharma et al, 1996;Ye et al, 2002;Zamora et al, 2012;Zheng et al, 201330e45 C Jenness & Palmer, 1945Montagne et al, 1999;Oehlmann et al, 1994;Shimizu & Yamauchi, 1982;Wiese & Palmer, 1932 1000e3000 (low) Cavaletto et al, 1999;Cebo, Caillat, Bouvier, & Martin, 2010;Chien & Richardson, 1967;Dalgleish & Banks, 1991;Dickow, Larsen, Hammershøj, & Wiking, 2011;Fortunato et al, 2003;Horisberger et al, 1977;Iametti et al, 1997;Kathriarachchi et al, 2014;…”

“…Measurements of MFGM proteins with SDS-PAGE and liquid chromatographyemass spectrometry/mass spectrometry (LCeMS/ MS) showed that even integral MFGM proteins (e.g., BTN) were depleted by washing procedures (Le et al, 2013;Zheng et al, 2013). Therefore, the authors concluded that larger MFGM fragments were lost during the wash procedure, and not only single proteins.…”

“…The purpose of studies by Zheng et al (2013) and Zheng, Jim enez-Flores, Gragson, and Everett (2014) was to gain insights into the stability of fat globules, the compositional changes of the fat globule surface, and the competitive binding strengths of key MFGM proteins during centrifugal washings. For this purpose, the authors investigated mild (3000 Â g; 5 min) and intensive (15,000 Â g; 20 min) washing procedures over three steps.…”

Impact of cream washing on fat globules and milk fat globule membrane proteins

“…Experimental setup of cream washing using a pilot scale cream separator.Measurements of MFGM proteins with SDS-PAGE and LC-MS/MS have shown that even integral MFGM proteins were depleted by washing procedures(Le et al, 2013;Zheng, Jim enez-Flores, & Everett, 2013).…”