Latitude and Skimming Process Effect on Cow’s Milk Content in Essential Inorganic Elements

Abstract

The objective of this study was to determine the mineral variation of cow’s milk as affected by latitude (north or south Europe; reflecting different feeding practices, i.e. grazing or not), and manufacturing process (different fat content). The mineral content of milk is particularly important to the infant food formula industry, whilst milk products cover a significant proportion of adult requirements in inorganic elements. Milk samples of pasteurized full fat milk were taken according to the origin of milk; southern Europe or north Europe during autumn; reflecting different feeding practices. Additionally, milk samples with different fat content 0, 1.5 and 3.5% were taken during the year, from manufacturing milk supplies. The elements determined were Ca, Mg, Zn, Mn, Cu, Fe by the use of atomic absorption spectroscopy, and P was determined through UV-VIS spectrophotometer. Milk fat removal significantly increased the macro mineral content Ca, P, and Mg. Manufacturing process did not affect micro element content. Latitude did not have significant impact on the content of macro minerals, but significant effect on Cu and Mn content. Higher Cu content in milk of south origin was probably related to higher concentrate to forage ratio fed. Higher Mn content in milk of north origin could be attributed to hay or/and drinking water of high industrialized countries. The elements Zn and Fe were not affected by manufacturing process neither by latitude. It was concluded that only Cu can be substantially manipulated through animal nutrition. Food composition tables should be updated as macro inorganic element content of milk is reduced gradually corresponding to higher yielding cows, whilst trace element content tend to increase as a result of higher proportion of concentrates fed.