503 International Symposia Risk Factors for Environment and Food Safety & Natural Resources and Sustainable Development, Faculty of Environmental Protection, November 6-7 Oradea 2009 INVESTIGATION OF THE PROTEIN FRACTIONS IN GOAT MILK WITH RP-HPLC TO OPTIMALIZE THE MILK PROCESSING Ottillia Bara-Herczegh, József Csanádi, Gabriella Török University of Szeged, Faculty of Engineering Abstract The amount of protein in milk (which varies between different species of mammals) is critical to its commercial, technological and biological value. Caprine milk differs from cow milk in several physico-chemical characteristics, which explain major differences in the technological behaviour of the two milks. Goat milk also has different proportions of the four major caseins (α s1 , α s2, β, κ) compared to cow counterparts, and there are great variations, especially between α s1 -casein and α s2 -casein contents between individuals and breeds of goats, because of the occurrence of genetic polymorphisms for all milk proteins, which influence greatly their cheese making properties. The aim of our study was to adopt BORDIN’s (2001) RP-HPLC method for analysis the casein fractions of denatured goat milk samples. The separation of main caseins (α s, β, κ) was successful by ion-pair reversed phase HPLC with the help of casein standards originated from cow milk. Our results are well correlated with the data of references. Keywords: goat milk, casein fractions, separation, HPLC INTRODUCTION Goat milk is traditionally consumed directly or as handmade cheese (Medina and Nuňez, 2004). It is a source of proteins of excellent quality, thanks to the proportion of essential amino acids they provide (Park 2006). Goat milk is also highly digestible and the biological value of its proteins is superior to that of cow milk proteins (Haenlein, 2004, Almaas et al. 2008). Its nutritional properties and lower allergenicity in comparison to cow milk, especially in nonsensitised children (Haenlein, 2004; Park & Haenlein, 2006), has led to an increased interest in goat milk as a functional food, and it now forms a part of the current trend to healthy eating in developed countries (Michaelidou, 2008, Raynal- Ljutovac et al. 2008). The amount of protein in milk (which varies between different species of mammals) is critical to its commercial, technological and biological value. Thus, the greater the quantity of proteins in the raw milk, the higher is its performance in the technological transformation required to prepare derivatives, such as fermented milks or cheeses (Raynal-Ljutovac et al. 2008, Pirisi et al. 2007). In recent years, increasing attention has been paid to the measurement of specific protein fractions in milk, obtained by digestion of the protein. These protein fractions, in addition