Fractionation of whey proteins from red deer (Cervus elaphus) milk and comparison with whey proteins from cow, sheep and goat milks

In the present study, we report the first protein fractionation analysis of whey proteins from red deer (Cervus elaphus) milk. The aim of this study was to investigate the protein composition of red deer milk and examine the protein profile compared with that of cow, sheep and goat using 1D-PAGE and protein RP-HPLC of defatted milk. Ammonium sulfate fractionated sweet whey proteins of the four species were further subjected to anion exchange chromatography, and 1D- and large format 2D-PAGE analysis. Deer milk caseins displayed different mobility on 1D-PAGE, and chromatographed differently on RP-HPLC to those of other species. The apparent ratio of alpha-lactalbumin to beta-lactoglobulin in red deer milk was different compared to other species. As cheese wheys from other ruminants have been shown to contain proteins and peptides with health promoting benefits, it is of interest to characterize proteins in red deer whey, a by-product of an emerging novel deer cheese manufacture venture. Red deer sweet whey, as well as other species, could be fractionated to obtain a fraction partially depleted of alpha-lactalbumin and beta-lactoglobulin, which facilitated display of lower abundance proteins by 1D- and 2D-PAGE. Furthermore, a difference in casein coagulation during sweet whey production from milks of red deer and other species was observed.