Traditional sheep production for meat and wool for meat and wool among small and medium-sized Chilean farmers has low profitability. Therefore, there is interest in producing value-added, differentiated products. One alternative is the production of sheep milk and cheese. This arricie analyzes and discusses existing alternatives for modifying milk and cheese compositions with the aim of differentiating these products. Also, analytical techniques that allowthe chemical characterization of milk and cheese are briefly mentioned. The main international thrusts are focused on the modification of the content and composition of milk fatty acids and on the identification of volatile compounds, terpenes, polyphenols and other analytes that allow differentiation of cheese types on the basis of aroma, taste and flavor and that would help in ensuring traceability.