Vol.5 (2015) No. 3 ISSN: 2088-5334 Preliminary Metabolomic Analysis of Goat Milk from Different Breeds Using Mass Spectrometry Mohamad Razlan Abd Rahman #1 , Zaiton Hassan #2 , Mohd. Sukri Hassan #3 , Roshada Hashim #4 , Norlelawati Arifin #5 , and Mohd Nazmi Abdul Manap #6 # Faculty of Science & Technology, Universiti Sains Islam Malaysia (USIM), 71800 Nilai, Negeri Sembilan, Malaysia E-mail: 1 arazmahani2@gmail.com, { 2 bdrzaiton, 3 cmohdsukri, 4 dpengarah.ua, 5 enorlela, 6 fnazmi} @usim.edu.my Abstract— Metabolomics facilitates the identification of numerous metabolites in a sample with mass less than 1 kD. The purpose of this study was to determine the effect of feed on the metabolites in raw goat milk samples obtained from two breeds namely Saanen and Shami that were collected from a farm in Selangor and Negeri Sembilan, Malaysia, respectively. The types of feed given to the goats were recorded. The fat in the samples were removed via centrifugation before analysis using liquid chromatography quadrupole time of flight mass spectrometry (LC-QToF-MS). From the chromatograms obtained the presence of veterinary drug residue, di- and tri-peptides, short and long-chain fatty acids, some components from plants, and insecticide residue were detected using HMP, KEGG, LMP, and METLIN databases identification. It is expected that through metabolomics study it may be possible to formulate the feed and determine the breed that give good quality milk. Keywords— Metabolomics, goat milk, LC-QToF-MS, databases. I. INTRODUCTION In the last 20 years scientists begin to realise that a simultaneous compound or metabolite identification method would assist in confirming health and physiological status of an organism. Metabolites represent a diverse group of low- molecular-weight structures including lipids, amino acids, peptides, nucleic acids, organic acids, vitamins, thiols and carbohydrates [1]. Metabolomics aims to detect, identify, and quantify a total population of low molecular weight compounds to gain functional information in a biological system [2]. Milk is a complex biological fluid secreted for neonate nourishment and development. Milk contains water, lipids, carbohydrates, proteins, vitamins, minerals, and smaller metabolites. Changes in chemical composition of milk affect nutritional, safety, and technological properties of the milk [3]. In addition to the normal nutritional composition, goat milk contains other metabolites that have functional properties and may be unique to type of feed and breed [4], [5]. Sundekilde [6] suggested that metabolomics approach can be used to establish biomarkers in bovine milk as a diagnostic tool for determining quality and technological properties. Metabolites as biomarkers for specific biochemical pathways will indicate different physiological status of the organism [2]. In addition, coupling chromatography to mass spectrometry (MS) offers an excellent solution to complex mixture analyses and has been extensively used in metabolomics. Chromatographic separation of metabolites prior to MS analyses has several advantages: i) reduces matrix effects and ionization suppression, ii) separates isomers, iii) provides additional and orthogonal data (i.e. retention time/factor/index) valuable for metabolite annotation, and iv) allows for more accurate quantification of individual metabolites [7]. Nevertheless it has now become relatively routine to comprehensively compare the levels of thousands of metabolite peaks in one sample group to another in an untargeted manner. This approach, called untargeted metabolomics, has the potential to implicate unexpected pathways with a unique phenotype or disease process [8]. Reaves [9] coined out that one of the uses of metabolomics data is to pick out a few interesting compounds for further study. This was the further emphasized by [10], whereby he classified a high quality milk as having low somatic cell count (SCC), low standard plate count (SPC), no human pathogen, and no antibiotic residues. Hence, this preliminary effort aims at profiling the metabolites of goat milk in selected farms in some parts of Peninsular Malaysia. 181