Elemental distribution and fatty acid profile of raw goat milk: effect of dietary olive pellets on milk nutritional value

Abstract

Background: Milk is one of the important drinks for human and serves many nutrients including trace elements required for growth. In terms of prediction of element availability in food, fractionation analysis is helpful for understanding element partitioning. Objective: The current study was conducted to examine the effect of dietary olive pellets on goat milk. The milk samples of goats which were fed with basal diet and olive pellet added basal diet were investigated. Method: Lipid, protein and serum fractions of milk were separated and elements including Fe, Cu, Zn, Mn, Mg, Ca, Cr, Ni, Mo, Al, Ba, Pb, Sn, V, Co and Cd were detected using inductively coupled plasma optic emission spectrometry. Results: The distribution tendency of the elements was variable. The relatively highest bioavailable metal species were found in the milk of olive pellet fed goats, and the percentages were between 5.4 and 83.6%. Sum of the element contents of lipid, protein and serum fractions was compared with whole sample analysis and recoveries were between 93.3 and 110.7%. Fatty Acid (FA) profile of the milk samples was determined using gas chromatography. Classification of milk samples was carried out based on FA contents by principal component analysis. The milk obtained from goats fed with olive pellets have been shown to be similar in terms of polyunsaturated, monounsaturated and long chain FA contents. Conclusion: The results of the present study indicated that feeding the goats with olive pellets improves the quality of milk in terms of FA content. On the other hand, distribution of the elements between investigated fractions was not remarkable.